Add a test for CSS variables

This will be necessary for supporting variables in animations.

.gitlab-ci.yml

@@ -26,8 +26,7 @@ variables:
   BACKEND_FLAGS: "-Dx11-backend=true -Dwayland-backend=true -Dbroadway-backend=true"
   FEATURE_FLAGS: "-Dvulkan=enabled -Dcloudproviders=enabled -Dbuild-testsuite=true -Dintrospection=enabled"
   MESON_TEST_TIMEOUT_MULTIPLIER: 3
-  MESON_TEST_MAX_PROCESSES: 8
-  FEDORA_IMAGE: "registry.gitlab.gnome.org/gnome/gtk/fedora:v52"
+  FEDORA_IMAGE: "registry.gitlab.gnome.org/gnome/gtk/fedora:v49"
 
 workflow:
   rules:
@@ -68,6 +67,7 @@ style-check-diff:
         - "${CI_PROJECT_DIR}/_build/report-x11.xml"
         - "${CI_PROJECT_DIR}/_build/report-wayland.xml"
         - "${CI_PROJECT_DIR}/_build/report-wayland_gl.xml"
+        - "${CI_PROJECT_DIR}/_build/report-wayland_gles2.xml"
         - "${CI_PROJECT_DIR}/_build/report-broadway.xml"
     name: "gtk-${CI_COMMIT_REF_NAME}"
     paths:
@@ -117,12 +117,10 @@ release-build:
     EXTRA_MESON_FLAGS: "--buildtype=release"
   script:
     - .gitlab-ci/show-info-linux.sh
-    - mkdir _install
-    # don't use catch by default, since it causes sporadic test failures
-    # - export PATH="$HOME/.local/bin:${CI_PROJECT_DIR}/_install/bin:$PATH"
-    # - .gitlab-ci/install-meson-project.sh --prefix ${CI_PROJECT_DIR}/_install https://gitlab.gnome.org/jadahl/catch.git main
+    - export PATH="$HOME/.local/bin:$PATH"
     - meson subprojects download
     - meson subprojects update --reset
+    - mkdir _install
     - meson setup
             --prefix=${CI_PROJECT_DIR}/_install
             ${COMMON_MESON_FLAGS}
@@ -135,6 +133,8 @@ release-build:
     - PKG_CONFIG_PATH=${CI_PROJECT_DIR}/_install/lib64/pkgconfig:${CI_PROJECT_DIR}/_install/share/pkgconfig meson setup _build_hello examples/hello
     - LD_LIBRARY_PATH=${CI_PROJECT_DIR}/_install/lib64 meson compile -C _build_hello
     - .gitlab-ci/run-tests.sh _build wayland gtk
+    # only repeat test runs that are likely affected by test setups
+    - .gitlab-ci/run-tests.sh _build wayland_gles2 gtk:gdk,gtk:gsk-gl
 
 fedora-clang:
   extends: .build-fedora-default
@@ -198,11 +198,11 @@ fedora-mingw64:
       - subprojects/libepoxy/
       - subprojects/pango/
 
-msys2-ucrt64:
+msys2-mingw64:
   extends: .mingw-defaults
   needs: []
   variables:
-    MSYSTEM: "UCRT64"
+    MSYSTEM: "MINGW64"
     CHERE_INVOKING: "yes"
   artifacts:
     when: always
@@ -413,12 +413,11 @@ static-scan:
 # Run tests with the address sanitizer. We need to turn off introspection
 # and f16c, since they are incompatible with asan
 asan-build:
-  extends: .build-fedora-default
+  image: $FEDORA_IMAGE
   tags: [ asan ]
   stage: analysis
   needs: []
   variables:
-    MESON_TEST_MAX_PROCESSES: 4
   script:
     - export PATH="$HOME/.local/bin:$PATH"
     - CC=clang meson setup
@@ -446,10 +445,10 @@ reference:
             --force-fallback-for=gdk-pixbuf,pango
             -Dintrospection=enabled
             -Ddocumentation=true
-            -Dman-pages=true
+            -Dgtk_doc=true
             -Dgdk-pixbuf:gtk_doc=true
-            -Dpango:documentation=true
-            -Dbuild-demos=true
+            -Dpango:gtk_doc=true
+            -Dbuild-demos=false
             -Dbuild-examples=false
             -Dbuild-tests=false
             -Dbuild-testsuite=false
@@ -461,7 +460,6 @@ reference:
     - mv _build/docs/reference/gdk/gdk4-wayland/ _reference/gdk4-wayland/
     - mv _build/docs/reference/gsk/gsk4/ _reference/gsk4/
     - mv _build/docs/reference/gtk/gtk4/ _reference/gtk4/
-    - mv _build/docs/reference/gtk/*.html _reference/gtk4/
     - mv _build/subprojects/pango/docs/Pango/ _reference/Pango/
     - mv _build/subprojects/pango/docs/PangoCairo/ _reference/PangoCairo/
     - mv _build/subprojects/pango/docs/PangoFc/ _reference/PangoFc/

.gitlab-ci/fedora.Dockerfile

@@ -1,4 +1,4 @@
-FROM fedora:40
+FROM fedora:39
 
 RUN dnf -y install \
     adwaita-icon-theme \
@@ -99,11 +99,8 @@ RUN dnf -y install \
     which \
     wireplumber \
     xorg-x11-server-Xvfb \
- && dnf -y update \
  && dnf clean all
 
-RUN rm /usr/share/vulkan/icd.d/powervr_mesa_icd.x86_64.json
-
 # Enable sudo for wheel users
 RUN sed -i -e 's/# %wheel/%wheel/' -e '0,/%wheel/{s/%wheel/# %wheel/}' /etc/sudoers
 

.gitlab-ci/flatpak-build.sh

@@ -19,12 +19,13 @@ flatpak build ${builddir} meson \
                 --buildtype=debugoptimized \
                 -Dx11-backend=true \
                 -Dwayland-backend=true \
+                -Dvulkan=disabled \
                 -Dbuild-tests=false \
                 -Dbuild-testsuite=false \
                 -Dbuild-examples=false \
                 -Dintrospection=disabled \
                 -Dbuild-demos=true \
-                -Dprofile=devel \
+                -Ddemo-profile=devel \
                 _flatpak_build
 
 flatpak build --env=CI_COMMIT_SHORT_SHA=$CI_COMMIT_SHORT_SHA ${builddir} ninja -C _flatpak_build install

.gitlab-ci/install-meson-project.sh

@@ -1,91 +0,0 @@
-#!/bin/bash
-
-set -e
-
-usage() {
-  cat <<-EOF
-	Usage: $(basename $0) [OPTION…] REPO_URL COMMIT
-
-	Check out and install a meson project
-
-	Options:
-	  -Dkey=val      Option to pass on to meson
-	  --prefix       Prefix to install to
-	  --subdir       Build subdirectory instead of whole project
-	  --prepare      Script to run before build
-
-	  -h, --help     Display this help
-
-	EOF
-}
-
-TEMP=$(getopt \
-  --name=$(basename $0) \
-  --options='D:h' \
-  --longoptions='prefix:' \
-  --longoptions='subdir:' \
-  --longoptions='prepare:' \
-  --longoptions='help' \
-  -- "$@")
-
-eval set -- "$TEMP"
-unset TEMP
-
-MESON_OPTIONS=()
-PREFIX=/usr
-SUBDIR=.
-PREPARE=:
-
-while true; do
-  case "$1" in
-    -D)
-      MESON_OPTIONS+=( -D$2 )
-      shift 2
-    ;;
-
-    --prefix)
-      PREFIX=$2
-      shift 2
-    ;;
-
-    --subdir)
-      SUBDIR=$2
-      shift 2
-    ;;
-
-    --prepare)
-      PREPARE=$2
-      shift 2
-    ;;
-
-    -h|--help)
-      usage
-      exit 0
-    ;;
-
-    --)
-      shift
-      break
-    ;;
-  esac
-done
-
-if [[ $# -lt 2 ]]; then
-  usage
-  exit 1
-fi
-
-REPO_URL="$1"
-COMMIT="$2"
-
-CHECKOUT_DIR=$(mktemp --directory)
-trap "rm -rf $CHECKOUT_DIR" EXIT
-
-git clone --depth 1 "$REPO_URL" -b "$COMMIT" "$CHECKOUT_DIR"
-
-pushd "$CHECKOUT_DIR/$SUBDIR"
-sh -c "$PREPARE"
-meson setup --prefix "$PREFIX" _build "${MESON_OPTIONS[@]}"
-meson compile -C _build
-meson install -C _build
-popd

.gitlab-ci/run-tests.sh

@@ -8,19 +8,17 @@ builddir=$1
 setup=$2
 suite=$3
 multiplier=${MESON_TEST_TIMEOUT_MULTIPLIER:-1}
-n_processes=${MESON_TEST_MAX_PROCESSES:-1}
 
 # Ignore memory leaks lower in dependencies
 export LSAN_OPTIONS=suppressions=$srcdir/lsan.supp:print_suppressions=0:detect_leaks=0:allocator_may_return_null=1
+export G_SLICE=always-malloc
 
 case "${setup}" in
   x11*)
-    dbus-run-session -- \
-       xvfb-run -a -s "-screen 0 1024x768x24 -noreset" \
+    xvfb-run -a -s "-screen 0 1024x768x24 -noreset" \
           meson test -C ${builddir} \
                 --quiet \
                 --timeout-multiplier "${multiplier}" \
-                --num-processes "${n_processes}" \
                 --print-errorlogs \
                 --setup=${setup} \
                 --suite=${suite//,/ --suite=} \
@@ -42,11 +40,9 @@ case "${setup}" in
     compositor=$!
     export WAYLAND_DISPLAY=wayland-5
 
-    dbus-run-session -- \
-          meson test -C ${builddir} \
+    meson test -C ${builddir} \
                 --quiet \
                 --timeout-multiplier "${multiplier}" \
-                --num-processes "${n_processes}" \
                 --print-errorlogs \
                 --setup=${setup} \
                 --suite=${suite//,/ --suite=} \
@@ -67,11 +63,9 @@ case "${setup}" in
     server=$!
     export BROADWAY_DISPLAY=:5
 
-    dbus-run-session -- \
-          meson test -C ${builddir} \
+    meson test -C ${builddir} \
                 --quiet \
                 --timeout-multiplier "${multiplier}" \
-                --num-processes "${n_processes}" \
                 --print-errorlogs \
                 --setup=${setup} \
                 --suite=${suite//,/ --suite=} \

.gitlab-ci/test-msys2.sh

@@ -2,6 +2,12 @@
 
 set -e
 
+if [[ "$MSYSTEM" == "MINGW32" ]]; then
+    export MSYS2_ARCH="i686"
+else
+    export MSYS2_ARCH="x86_64"
+fi
+
 # Update everything
 pacman --noconfirm -Suy
 
@@ -9,27 +15,26 @@ pacman --noconfirm -Suy
 pacman --noconfirm -S --needed \
     base-devel \
     git \
-    ${MINGW_PACKAGE_PREFIX}-cc \
-    ${MINGW_PACKAGE_PREFIX}-ccache \
-    ${MINGW_PACKAGE_PREFIX}-pkgconf \
-    ${MINGW_PACKAGE_PREFIX}-gobject-introspection \
-    ${MINGW_PACKAGE_PREFIX}-meson \
-    ${MINGW_PACKAGE_PREFIX}-adwaita-icon-theme \
-    ${MINGW_PACKAGE_PREFIX}-atk \
-    ${MINGW_PACKAGE_PREFIX}-cairo \
-    ${MINGW_PACKAGE_PREFIX}-gdk-pixbuf2 \
-    ${MINGW_PACKAGE_PREFIX}-glib2 \
-    ${MINGW_PACKAGE_PREFIX}-graphene \
-    ${MINGW_PACKAGE_PREFIX}-json-glib \
-    ${MINGW_PACKAGE_PREFIX}-libepoxy \
-    ${MINGW_PACKAGE_PREFIX}-pango \
-    ${MINGW_PACKAGE_PREFIX}-fribidi \
-    ${MINGW_PACKAGE_PREFIX}-gst-plugins-bad-libs \
-    ${MINGW_PACKAGE_PREFIX}-shared-mime-info \
-    ${MINGW_PACKAGE_PREFIX}-python-gobject \
-    ${MINGW_PACKAGE_PREFIX}-shaderc \
-    ${MINGW_PACKAGE_PREFIX}-vulkan \
-    ${MINGW_PACKAGE_PREFIX}-vulkan-headers
+    mingw-w64-$MSYS2_ARCH-cc \
+    mingw-w64-$MSYS2_ARCH-ccache \
+    mingw-w64-$MSYS2_ARCH-pkgconf \
+    mingw-w64-$MSYS2_ARCH-gobject-introspection \
+    mingw-w64-$MSYS2_ARCH-meson \
+    mingw-w64-$MSYS2_ARCH-adwaita-icon-theme \
+    mingw-w64-$MSYS2_ARCH-atk \
+    mingw-w64-$MSYS2_ARCH-cairo \
+    mingw-w64-$MSYS2_ARCH-gdk-pixbuf2 \
+    mingw-w64-$MSYS2_ARCH-glib2 \
+    mingw-w64-$MSYS2_ARCH-graphene \
+    mingw-w64-$MSYS2_ARCH-json-glib \
+    mingw-w64-$MSYS2_ARCH-libepoxy \
+    mingw-w64-$MSYS2_ARCH-pango \
+    mingw-w64-$MSYS2_ARCH-fribidi \
+    mingw-w64-$MSYS2_ARCH-gst-plugins-bad-libs \
+    mingw-w64-$MSYS2_ARCH-shared-mime-info \
+    mingw-w64-$MSYS2_ARCH-python-gobject \
+    mingw-w64-$MSYS2_ARCH-shaderc \
+    mingw-w64-$MSYS2_ARCH-vulkan
 
 mkdir -p _ccache
 export CCACHE_BASEDIR="$(pwd)"
@@ -39,7 +44,7 @@ export CCACHE_DIR="${CCACHE_BASEDIR}/_ccache"
 ccache --zero-stats
 ccache --show-stats
 export CCACHE_DISABLE=true
-meson setup \
+meson \
     -Dx11-backend=false \
     -Dwayland-backend=false \
     -Dwin32-backend=true \

.gitlab/issue_templates/Bug.md

@@ -34,9 +34,7 @@
 <!--
  - Which version of GTK you are using
  - What operating system and version
- - What windowing system (X11 or Wayland)
- - What graphics driver / mesa version
- - For Linux, which distribution
+  - For Linux, which distribution
  - If you built GTK yourself, the list of options used to configure the build
 -->
 

CONTRIBUTING.md

@@ -35,7 +35,7 @@ The issue tracker is meant to be used for actionable issues only.
 
 You should not open a new issue for security related questions.
 
-When in doubt, follow the process for [GNOME security issues](https://security.gnome.org/).
+When in doubt, follow [security](https://security.gnome.org/).
 
 ### Bug reports
 
@@ -100,16 +100,14 @@ development tools appropriate for your operating system, including:
  - Meson
  - Ninja
  - Gettext (19.7 or newer)
- - a [C99 compatible compiler][glib-toolchain-reqs]
+ - a [C99 compatible compiler](https://wiki.gnome.org/Projects/GLib/CompilerRequirements)
 
 Up-to-date instructions about developing GNOME applications and libraries
 can be found on [the GNOME Developer Center](https://developer.gnome.org).
 
 The GTK project uses GitLab for code hosting and for tracking issues. More
-information about using GitLab can be found on [the GNOME handbook][handbook].
-
-[glib-toolchain-reqs]: https://gitlab.gnome.org/GNOME/glib/-/blob/main/docs/toolchain-requirements.md
-[handbook]: https://handbook.gnome.org/infrastructure/gitlab.html
+information about using GitLab can be found [on the GNOME
+wiki](https://wiki.gnome.org/GitLab).
 
 ### Dependencies
 
@@ -133,7 +131,7 @@ GTK will attempt to download and build some of these dependencies if it
 cannot find them on your system.
 
 Additionally, you may want to look at projects that create a development
-environment for you, like [jhbuild](https://gitlab.gnome.org/GNOME/jhbuild)
+environment for you, like [jhbuild](https://wiki.gnome.org/HowDoI/Jhbuild)
 and [gvsbuild](https://github.com/wingtk/gvsbuild).
 
 ### Getting started
@@ -146,28 +144,33 @@ $ git clone https://gitlab.gnome.org/yourusername/gtk.git
 $ cd gtk
 ```
 
+**Note**: if you plan to push changes to back to the main repository and
+have a GNOME account, you can skip the fork, and use the following instead:
+
+```sh
+$ git clone git@gitlab.gnome.org:GNOME/gtk.git
+$ cd gtk
+```
+
 To compile the Git version of GTK on your system, you will need to
 configure your build using Meson:
 
 ```sh
-$ meson setup _builddir .
-$ meson compile -C _builddir
+$ meson _builddir .
+$ cd _builddir
+$ ninja
 ```
 
 Typically, you should work on your own branch:
 
 ```sh
-$ git switch -C your-branch
+$ git checkout -b your-branch
 ```
 
 Once you've finished working on the bug fix or feature, push the branch
 to the Git repository and open a new merge request, to let the GTK
 maintainers review your contribution.
 
-**Important**: Do **not** attach a diff or a patch file to a GitLab issue.
-Patches cannot be reviewed, and do not not go through the CI pipeline. If
-you wish to submit your changes to GTK, always use a merge request.
-
 ### Code reviews
 
 Each contribution is reviewed by the core developers of the GTK project.
@@ -259,4 +262,4 @@ people committing to GTK to follow a few rules:
 
 If you have been contributing to GTK for a while and you don't have commit
 access to the repository, you may ask to obtain it following the [GNOME account
-process](https://handbook.gnome.org/infrastructure/developer-access.html).
+process](https://wiki.gnome.org/AccountsTeam/NewAccounts).

NEWS

@@ -1,648 +1,6 @@
-Overview of Changes in 4.17.0, xx-xx-xxxx
+Overview of Changes in 4.14.2, xx-xx-xxxx
 =========================================
 
-
-Overview of Changes in 4.16.2, 09-25-2024
-=========================================
-
-* GtkLabel:
- - Fix centered text in RTL
-
-* Gsk:
- - Speed up some Vulkan operations
- - Improve startup speed by avoiding initialization
-   of GL and Vulkan in most cases
- - Reduce critials at startup to warnings
- - Fix a crash on startup with some Vulkan drivers
- - Fix a big texture leak in NGL
-
-* Gdk:
- - Speed up memory format conversions
-
-* Wayland:
- - Be more careful with mimetypes during DND or copy-paste
-
-* Tools:
- - builder-tool: Improve conversion of boxes
-
-* Translation updates:
- Brazilian Portuguese
- Bulgarian
- Catalan
- Chinese (China)
- Georgian
- German
- Hebrew
- Indonesian
- Persian
- Polish
- Portuguese
- Slovenian
- Spanish
- Turkish
- Ukrainian
-
-
-Overview of Changes in 4.16.1, 09-16-2024
-=========================================
-
-* GtkFileChooser:
- - Plug a memory leak
-
-* GtkCalendar:
- - Avoid ending up with invalid dates
-
-* Printing:
- - Fix initial printer selection in the print dialog
-
-* Gsk:
- - Fix shadows for opaque textures
- - Fix a crash in a corner case
-
-* Css:
- - Make relative paths work again in theme files
-
-* Accessibility:
- - Fix detection of the Flatpak portal
-
-* MacOS:
- - Fix keyboard input in popovers
- - Keep DND icons above regular windows
- - Ignore events from DND icons
-
-* Translation updates
- Basque
- British English
- Bulgarian
- Czech
- Danish
- Georgian
- Hungarian
- Lithuanian
- Portuguese
- Spanish
- Swedish
-
-
-Overview of Changes in 4.16.0, 09-06-2024
-=========================================
-
-Note: This release changes the default GSK renderer to be Vulkan,
-on Wayland. Other platforms still use ngl. The intent of this change
-is to use the best available platform APIs. You can still override
-the renderer choice using the GSK_RENDERER environment variable.
-
-We believe that most of the problems reported with the new renderers
-during the 4.13 and 4.15 development cycles have been addressed by now.
-
-But the new renderers and dmabuf support are using graphics drivers
-in different ways than the old gl renderer, and trigger new driver bugs.
-Therefore, it is recommended to use the latest mesa release (24.2)
-with the new renderers.
-
-* GtkScale:
- - Fix positioning of scale values
-
-* GtkEmojiChooser:
- - Make Control-clicks work for the recent section
-
-* GtkPopover:
- - Make sure focus lands on the right widget when cascading
-
-* GtkSpinButton:
- - Disable Emoji input for numeric spin buttons
-
-* GtkSingleSelection:
- - Implement unselect_all
-
-* Accssibility:
- - Fix roles for radio buttons
- - Check if ATs are listening before exporting trees
- - Add a check for sandboxed accessibility bus
- - Fix handling of the error message relation
- - Turn criticals into debug messages
- - Set expanded states properly in menus
-
-* CSS:
- - Fix a few issues on bigendian systems
- - Avoid a crash with relative colors
-
-* GSK:
- - Use the right GL context when exporting textures
- - Don't let colors influence depth decisions
- - Allow uploading of mipmap levels when tiling textures
-
-* GDK:
- - Update keysyms from libX11 1.8.10
- - Implement cpu-side mipmapping
- - Use a thread pool for color conversions and mipmapping
-
-* Vulkan:
- - Fix drag surface offsets
-
-* Wayland:
- - Fix a crash
- - Associate EGL windows with context later
-
-* X11:
- - Fix initial EGL context creation
- - Fix a problem with GL context creation
-
-* Broadway:
- - Implement compute_size and request_layout
-
-* MacOS:
- - Set transparent backgroiund for toplevel windows
-
-* Windows:
- - Improve debug output
- - Detect Mesas d3d12 driver and request GDI compat
-
-* Demos:
- - Set window icons in demos
- - Add a 64k x 64k image to the image scaling demo
-
-* Translation updates
- Belarusian
- Brazilian Portuguese
- Catalan
- Czech
- Galician
- German
- Hebrew
- Indonesian
- Korean
- Lithuanian
- Persian
- Polish
- Portuguese
- Slovenian
- Spanish
- Turkish
- Ukrainian
-
-
-Overview of Changes in 4.15.6, 08-26-2024
-=========================================
-
-* GtkCheckButton:
- - Add a grouped style class for radio buttons
-
-* GtkScale:
- - Fix alignment and positioning problems
-
-* Css:
- - Fix crashes in the variable support
-
-* Gsk:
- - Make graphics offloading work better with kwin
- - Make colorstate transfer functions more robust
- - GC dead textures more agressively
- - Only use a single render pass per frame
-
-* GL:
- - Round damage rectangles properly
- - Use the shared context when creating textures
- - Fix a file descriptor leak in dmabuf export
-
-* Vulkan:
- - Round damage rectangles properly
-
-* Wayland:
- - Work with the kwin implementation of xx-color-management-v4
-
-* Windows:
- - Make gtk_show_uri use SHOpenWithDialog()
- - Enable incremental rendering with WGL
-
-* Macos:
- - Open context menus on Ctrl-left click
-
-* Debugging:
- - Show color state information in the inspector
- - Collect input event traces in the recorder
- - Add shortcuts for toggling recording: Super-r
-   and for screenshots: Super-c
- - Split the GDK_DEBUG env var into GDK_DEBUG and GDK_DISABLE
- - Add GDK_DISABLE=color-mgmt and GDK_DISABLE=offload
-
-* Tools:
- - Add a 'Paste as node' action in gtk4-node-editor
-
-* Translations updates
- Basque
- Belarusian
- Brazilian Portuguese
- Chinese (China)
- Georgian
- Hebrew
- Hindi
- Russian
- Slovenian
- Turkish
- Ukrainian
-
-
-Overview of Changes in 4.15.5, 11-08-2024
-=========================================
-
-* GtkTextView:
- - ADd GtkTextBufferCommitNotify
-
-* CSS:
- - Propagate color state information to GSK for many features:
-   colors, borders, shadows, text
-
-* Gdk:
- - Fix an fd leak in the Vulkan code
- - Fix a leak of EGLSurfaces and DMA buffers
- - Set the opaque region of surfaces automatically based on their content
-
-* Gsk:
- - Fix Emoji rendering in Vulkan
- - Rework color handling to take color states into account
- - Implement more powerful occlusion culling
- - Minimize our use of renderpasses
-
-* Macos:
- - Fix window transparency
-
-* Debugging:
- - The inspector shows details about color states
-
-* Deprecations:
- - gdk_draw_context_begin/end_frame
- - gdk_surface_set_opaque_region
-
-* Build:
- - Require gstreamer 1.24
-
-* Translation updates
- Romanian
-
-
-Overview of Changes in 4.15.4, 30-07-2024
-=========================================
-
-* GtkPopover:
- - Fix size allocation with wrapping labels
-
-* GtkColumnView:
- - Check column visibility when measuring
-
-* CSS:
- - Fix fallout from recent changes
- - Make implementation of currentcolor inheritance match browsers
-
-* Gdk:
- - Introduce GdkColorState for encoding color space information
-   Currently, we support srgb, srgb-linear, rec2100-pq and rec2100-linear
- - Add color states to GdkTexture, as well as to the texture builder
-   and downloader objects, and convert as necessary
- - Add GdkMemoryTextureBuilder
- - Attach color states when loading or saving textures
- - Add GdkCicpParams to create color state objects for cicp tuples
- - Drop GDK_DEBUG=vulkan-validate
-   Use VK_INSTEANCE_LAYERS=VK_LAYER_KHRONOS_validation instead
-
-* Gsk:
- - Improve caching of glyphs and textures
- - Remove the uber shader
- - Numerous bug fixes
- - Fix corner cases in offload handling
- - Implement occlusion culling for opaque content
- - Allow offloading (some) transformed textures
- - Take colorstate into account when compositing
- - Add GDK_DEBUG=linear to opt into linear compositing
- - Implement tiling for large textures
- - Stop using descriptors and go back to simpler texture
-   management that should work better with older GL
- - Use correct shader clip mode for glyphs
- - Improve shadow rendering
-
-* Media:
- - Attach color states to textures obtained from gstreamer
-
-* Wayland:
- - Allow offloading GL textures via dmabuf export
- - Suppot the xx-color-management-v4 protocol
-
-* Deprecations:
- - GskGLShader and the render node
-
-* Tools:
- - Improve the rendernode tool extract command
- - Add an image tool that is about manipulating textures
-
-* Build:
- - GTK now requires a C11 compiler
-
-* Translation updates
- Georgian
- Hebrew
- Hindi
- Occitan
- Slovenian
-
-
-Overview of Changes in 4.15.3, 29-06-2024
-=========================================
-
-* Accessibility:
- - Only emit notifications when cursor positions change in GtkText
- - Fix handling of help text properties
-
-* CSS:
- - Fix some crashes introduced in recent currentcolor changes
-
-* DND:
- - Avoid a critical
-
-* Documentation:
- - Fix many oversights and missing docs
-
-* maxOS:
- - Add native keyboard shortcuts
-
-
-Overview of Changes in 4.15.2, 28-06-2024
-=========================================
-
-* GtkFileChooserWidget:
- - Plug some memory leaks
- - Make Ctrl-Shift-N create a new folder
-
-* GtkPopover:
- - Handle resizing and position changes better
-
-* CSS:
- - Support color(), oklab(), etc (https://www.w3.org/TR/css-color-4/)
- - Support color-mix() (https://www.w3.org/TR/css-color-5/)
- - Support relative colors (https://www.w3.org/TR/css-color-5/)
- - Support more colorspaces in color()
- - Allow percentages for opacity
- - Handle currentcolor more correctly
-
-* Accessibility:
- - Avoid markup when reading labels
-
-* GSK:
- - Subset fonts when serializing node trees
- - Make ngl export render_texture results as dmabufs
-
-* Wayland:
- - Use xdg-dialog protocol for attached dialogs
-
-* Windows:
- - Build with UNICODE
-
-* macOS:
- - Implement fullscreen-on-monitor
-
-* Documentation:
- - Widget shortcuts and actions are now described in the docs
-
-* Debugging:
- - Add GTK_DEBUG=css for warning about deprecated css syntax
-
-* Tools:
- - rendernode-tool: Add an extract command for data urls
-
-* Deprecations:
- - CSS Color functions shade(), lighter(), darker(), alpha(), mix()
-
-* Translation updates:
- Czech
- Hebrew
- Serbian
-
-
-Overview of Changes in 4.15.1, 21-05-2024
-=========================================
-
-* GtkGraphicsOffload:
- - Don't crash without a child
-
-* GtkSpinner:
- - Don't animate when unmapped
-
-* CSS:
- - Support the :root selector
- - Support variables and custom properties (https://www.w3.org/TR/css-variables-1/)
- - Implement math functions (https://www.w3.org/TR/css-values-4/)
- - Support modern syntax and calc in rgb() and hsl()
-
-* Icontheme:
- - Make symbolic svg loading more efficient
- - Handle color-free symbolics more efficiently
-
-* Accessibility:
- - Make the gtk-demo sidebar search more accessible
- - Stop emitting focus events
- - Realize child contexts when necessary
-
-* GDK:
- - Support XDG_ACTIVATION_TOKEN
- - dmabuf: Be more defensive when importing unknown formats to GL
- - dmabuf: Use narrow range for YUV
- - vulkan: Recreate swapchains when necessary or beneficial
-
-* GSK:
- - Improve logging for GDK_DEBUG=offload
- - Improve logging for GSK_DEBUG=renderer
- - gpu: Warn about inefficient texture import
- - gpu: Handle tiny offscreens correctly
- - vulkan: Add profiler marks in various places
- - vulkan: Fix a problem with imported dmabufs showing up black
- - cairo: Speed up mask nodes, since we use them for symbolic icons
-
-* Wayland:
- - Use wl_compositor version 6
-
-* X11:
- - Implement a missing method
-
-* Build:
- - Fix many ubsan warnings
-
-* Debugging:
- - Show more texture details in the recorder
- - Use GTK_DEBUG=css to see CSS deprecations
-
-* macOS:
- - Fix problems with events handed back to the OS
- - Respect GDK_DEBUG=default-settings
- - Allow applictions to handle Dock > Quit
-
-* Deprecations:
- - Use of @name colors in CSS
-
-* Translation updates:
- Catalan
- Georgian
- Hungarian
- Korean
- Portuguese
- Turkish
-
-
-Overview of Changes in 4.15.0, 21-04-2024
-=========================================
-
-This release changes the default GSK renderer to be Vulkan, on
-Wayland. Other platforms still use ngl.
-
-The intent of this change is to get wider testing and verify that
-Vulkan drivers are good enough for us to rely on. If significant
-problems show up, we will revert this change for 4.16.
-
-You can still override the renderer choice using the GSK_RENDERER
-environment variable.
-
----
-
-This release also changes font rendering settings by introducing
-a new high-level gtk-font-rendering settings which gives GTK more
-freedom to decide on font rendering.
-
-You can still use the low-level font-related settings by changing
-the new property to 'manual'.
-
----
-
-* GtkColumnView:
- - Fix infinite loops in dispose
- - Fix problems with weak ref cycles in GtkExpression
-
-* GtkListView:
-* GtkShortcutManager:
- - Track the propagation phase of added controllers
-
-* GtkGLArea:
- - Produce dmabuf textures, so graphics offload is possible
-
-* GtkTextView:
- - Support text shadows
-
-* GtkGraphicsOffload:
- - Add a black-background property
-
-* Settings:
- - Add a new gtk-font-rendering setting
-
-* Accessibility:
- - Add support for GetRangeExtents to GtkAccessibleText
- - Add support for GetOffsetAtPoint to GtkAccessibleText
- - Implement GtkAccessibleRange for scrollbars
-
-* GDK:
- - Add a callback-based cursor API
-
-* GSK:
--  Use the Vulkan renderer by default
- - Avoid an infinite recursion with offscreens in some cases
- - Optimize graphics offload to make it more likely that compositors
-   can use direct scanout
-
-* X11:
- - Fix some confusing debug messages
- - Drop a no-longer-relevant optimization that was interfering with
-   getting the current window manager capabilities
-
-* macOS:
- - Implement the color picker for macOS 10.15+
-
-* Debugging:
- - Snow monitor resolution in the inspector
-
-* Demos:
- - Use graphics offload in the shadertoy demo
- - Show more reliable fps numbers in the fishbowl demo
-
-* Tools:
- - Support generating pdf in gtk4-rendernode-tool
-
-* Build:
- - Require pango 1.52
- - Require cairo 1.18
- - Add a missing dependency that was causing build failures
- - Drop deprecated build options:
-   gtk_doc -> documentation
-   update_screenshots -> screenshots
-   demo-profile -> profile
-   demos -> build-demos
-
-* Deprecations:
- - gdk_widget_set/get_font_options
- - gdk_wayland/x11_display_set_cursor_theme
-
-* Translation updates:
- Basque
- Brazilian Portuguese
- British English
- Chinese (China)
- Hebrew
- Kabyle
- Persian
- Polish
- Russian
- Slovenian
- Swedish
- Turkish
-
-
-Overview of Changes in 4.14.2, 03-04-2024
-=========================================
-
-* GtkScale:
- - Improve positioning of values in some cases
-
-* Theme:
- - Make progress in entries visible
-
-* Accessibility:
- - Fix text insertion handling
-
-* GDK:
- - dnd: Use the default cursor durion motion
- - dnd: Use a better cursor for indicating the move action
-
-* GSK:
- - gl: Handle offloads in offscreen context better
- - Fix text rendering problems with some fonts
-
-* Wayland:
- - Tighten up some protocol version checks
- - Use the presentation time protocol
- - Fix a crash with subsurfaces
- - Improve settings portal handling
-
-* macOS:
- - Fix up the app menu support
-
-* Windows:
- - Fix problems with minimization
- - Fix build without fontconfig
-
-* Debugging:
- - Add font settings in the inspector
-
-* Demos:
- - Clean up the application demo
- - Update cursor images for the cursor demo
-
-* Translation updates:
- Catalan
- Czech
- French
- Georgian
- Hebrew
- Persian
- Slovenian
- Turkish
- Ukrainian
-
-
 Overview of Changes in 4.14.1, 16-03-2024
 =========================================
 

README.md

@@ -39,21 +39,18 @@ Nightly documentation can be found at
   - Gsk: https://gnome.pages.gitlab.gnome.org/gtk/gsk4/
 
 Nightly flatpaks of our demos can be installed from the
-[GNOME Nightly](https://nightly.gnome.org/) repository:
-
-```sh
-flatpak remote-add --if-not-exists gnome-nightly https://nightly.gnome.org/gnome-nightly.flatpakrepo
-flatpak install gnome-nightly org.gtk.Demo4
-flatpak install gnome-nightly org.gtk.WidgetFactory4
-flatpak install gnome-nightly org.gtk.IconBrowser4
-```
+[GNOME Nightly](https://wiki.gnome.org/Apps/Nightly) repository:
+  - `flatpak remote-add --if-not-exists gnome-nightly https://nightly.gnome.org/gnome-nightly.flatpakrepo`
+  - `flatpak install gnome-nightly org.gtk.Demo4`
+  - `flatpak install gnome-nightly org.gtk.WidgetFactory4`
+  - `flatpak install gnome-nightly org.gtk.IconBrowser4`
 
 Building and installing
 -----------------------
 
 In order to build GTK you will need:
 
-  - [a C11 compatible compiler](https://gitlab.gnome.org/GNOME/glib/-/blob/main/docs/toolchain-requirements.md)
+  - [a C99 compatible compiler](https://wiki.gnome.org/Projects/GLib/CompilerRequirements)
   - [Python 3](https://www.python.org/)
   - [Meson](http://mesonbuild.com)
   - [Ninja](https://ninja-build.org)
@@ -128,7 +125,7 @@ version, for example `gtk-4-10`.
 How to report bugs
 ------------------
 
-Bugs should be reported on the [issues page](https://gitlab.gnome.org/GNOME/gtk/issues/).
+Bugs should be reported on the [issues page](https://gitlab.gnome.org/GNOME/gtk/issues/new).
 
 In the bug report please include:
 
@@ -136,13 +133,9 @@ In the bug report please include:
 
    - which version of GTK you are using
    - what operating system and version
-   - what windowing system (X11 or Wayland)
-   - what graphics driver / mesa version
    - for Linux, which distribution
    - if you built GTK, the list of options used to configure the build
 
-  Most of this information can be found in the GTK inspector.
-
   And anything else you think is relevant.
 
 * How to reproduce the bug.

build-aux/flatpak/org.gtk.Demo4.json

@@ -185,8 +185,9 @@
             "builddir" : true,
             "config-opts" : [
                 "--libdir=/app/lib",
+                "-Dvulkan=disabled",
                 "-Dbuildtype=debugoptimized",
-                "-Dprofile=devel"
+                "-Ddemo-profile=devel"
             ],
             "sources" : [
                 {

build-aux/flatpak/org.gtk.IconBrowser4.json

@@ -114,8 +114,9 @@
             "builddir" : true,
             "config-opts" : [
                 "--libdir=/app/lib",
+                "-Dvulkan=disabled",
                 "-Dbuildtype=debugoptimized",
-                "-Dprofile=devel"
+                "-Ddemo-profile=devel"
             ],
             "sources" : [
                 {

build-aux/flatpak/org.gtk.WidgetFactory4.json

@@ -114,8 +114,9 @@
             "builddir" : true,
             "config-opts" : [
                 "--libdir=/app/lib",
+                "-Dvulkan=disabled",
                 "-Dbuildtype=debugoptimized",
-                "-Dprofile=devel"
+                "-Ddemo-profile=devel"
             ],
             "sources" : [
                 {
@@ -130,6 +131,7 @@
         "env" : {
             "DBUS_SESSION_BUS_ADDRESS" : "''",
             "GSK_RENDERER" : "opengl",
+            "GDK_DEBUG" : "vulkan-disable",
             "G_ENABLE_DEBUG" : "true"
         }
     }

build-aux/flatpak/org.gtk.gtk4.NodeEditor.json

@@ -114,8 +114,9 @@
             "builddir" : true,
             "config-opts" : [
                 "--libdir=/app/lib",
+                "-Dvulkan=disabled",
                 "-Dbuildtype=debugoptimized",
-                "-Dprofile=devel"
+                "-Ddemo-profile=devel"
             ],
             "sources" : [
                 {
@@ -130,6 +131,7 @@
         "env" : {
             "DBUS_SESSION_BUS_ADDRESS" : "''",
             "GSK_RENDERER" : "opengl",
+            "GDK_DEBUG" : "vulkan-disable",
             "G_ENABLE_DEBUG" : "true"
         }
     }

demos/constraint-editor/constraint-editor-application.c

@@ -0,0 +1,115 @@
+/*
+ * Copyright © 2019 Red Hat, Inc.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library. If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Authors: Matthias Clasen
+ */
+
+#include "config.h"
+
+#include "constraint-editor-application.h"
+#include "constraint-editor-window.h"
+
+struct _ConstraintEditorApplication
+{
+  GtkApplication parent_instance;
+};
+
+G_DEFINE_TYPE(ConstraintEditorApplication, constraint_editor_application, GTK_TYPE_APPLICATION);
+
+static void
+constraint_editor_application_init (ConstraintEditorApplication *app)
+{
+}
+
+static void
+quit_activated (GSimpleAction *action,
+                GVariant      *parameter,
+                gpointer       data)
+{
+  g_application_quit (G_APPLICATION (data));
+}
+
+static GActionEntry app_entries[] =
+{
+  { "quit", quit_activated, NULL, NULL, NULL }
+};
+
+static void
+constraint_editor_application_startup (GApplication *app)
+{
+  const char *quit_accels[2] = { "<Ctrl>Q", NULL };
+  const char *open_accels[2] = { "<Ctrl>O", NULL };
+  GtkCssProvider *provider;
+
+  G_APPLICATION_CLASS (constraint_editor_application_parent_class)->startup (app);
+
+  g_action_map_add_action_entries (G_ACTION_MAP (app),
+                                   app_entries, G_N_ELEMENTS (app_entries),
+                                   app);
+  gtk_application_set_accels_for_action (GTK_APPLICATION (app), "app.quit", quit_accels);
+  gtk_application_set_accels_for_action (GTK_APPLICATION (app), "win.open", open_accels);
+
+  provider = gtk_css_provider_new ();
+  gtk_css_provider_load_from_resource (provider, "/org/gtk/gtk4/constraint-editor/constraint-editor.css");
+  gtk_style_context_add_provider_for_display (gdk_display_get_default (),
+                                              GTK_STYLE_PROVIDER (provider),
+                                              GTK_STYLE_PROVIDER_PRIORITY_APPLICATION);
+}
+
+static void
+constraint_editor_application_activate (GApplication *app)
+{
+  ConstraintEditorWindow *win;
+
+  win = constraint_editor_window_new (CONSTRAINT_EDITOR_APPLICATION (app));
+  gtk_window_present (GTK_WINDOW (win));
+}
+
+static void
+constraint_editor_application_open (GApplication  *app,
+                                    GFile        **files,
+                                    int            n_files,
+                                    const char    *hint)
+{
+  ConstraintEditorWindow *win;
+  int i;
+
+  for (i = 0; i < n_files; i++)
+    {
+      win = constraint_editor_window_new (CONSTRAINT_EDITOR_APPLICATION (app));
+      constraint_editor_window_load (win, files[i]);
+      gtk_window_present (GTK_WINDOW (win));
+    }
+}
+
+static void
+constraint_editor_application_class_init (ConstraintEditorApplicationClass *class)
+{
+  GApplicationClass *application_class = G_APPLICATION_CLASS (class);
+
+  application_class->startup = constraint_editor_application_startup;
+  application_class->activate = constraint_editor_application_activate;
+  application_class->open = constraint_editor_application_open;
+}
+
+ConstraintEditorApplication *
+constraint_editor_application_new (void)
+{
+  return g_object_new (CONSTRAINT_EDITOR_APPLICATION_TYPE,
+                       "application-id", "org.gtk.gtk4.ConstraintEditor",
+                       "flags", G_APPLICATION_HANDLES_OPEN,
+                       NULL);
+}

demos/constraint-editor/constraint-editor-application.h

@@ -1,5 +1,5 @@
 /*
- * Copyright © 2024 Benjamin Otte
+ * Copyright © 2019 Red Hat, Inc.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ -14,19 +14,15 @@
  * You should have received a copy of the GNU Lesser General Public
  * License along with this library. If not, see <http://www.gnu.org/licenses/>.
  *
- * Authors: Benjamin Otte <otte@gnome.org>
+ * Authors: Matthias Clasen
  */
 
 #pragma once
 
-#include <glib.h>
+#include <gtk/gtk.h>
 
-G_BEGIN_DECLS
+#define CONSTRAINT_EDITOR_APPLICATION_TYPE (constraint_editor_application_get_type ())
 
-typedef void (* GdkTaskFunc) (gpointer user_data);
-
-void                    gdk_parallel_task_run               (GdkTaskFunc                 task_func,
-                                                             gpointer                    task_data);
-
-G_END_DECLS
+G_DECLARE_FINAL_TYPE (ConstraintEditorApplication, constraint_editor_application, CONSTRAINT, EDITOR_APPLICATION, GtkApplication)
 
+ConstraintEditorApplication *constraint_editor_application_new (void);

demos/constraint-editor/constraint-editor-window.c

@@ -0,0 +1,652 @@
+/*
+ * Copyright © 2019 Red Hat, Inc.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library. If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Authors: Matthias Clasen
+ */
+
+#include "config.h"
+
+#include "constraint-editor-window.h"
+#include "constraint-view.h"
+#include "constraint-editor.h"
+#include "guide-editor.h"
+
+struct _ConstraintEditorWindow
+{
+  GtkApplicationWindow parent_instance;
+
+  GtkWidget *paned;
+  GtkWidget *view;
+  GtkWidget *list;
+};
+
+G_DEFINE_TYPE(ConstraintEditorWindow, constraint_editor_window, GTK_TYPE_APPLICATION_WINDOW);
+
+static GtkConstraintTarget *
+find_target (GListModel          *model,
+             GtkConstraintTarget *orig)
+{
+  const char *name;
+  const char *model_name;
+  gpointer item;
+  int i;
+
+  if (orig == NULL)
+    return NULL;
+
+  if (GTK_IS_LABEL (orig))
+    name = gtk_label_get_label (GTK_LABEL (orig));
+  else if (GTK_IS_CONSTRAINT_GUIDE (orig))
+    name = gtk_constraint_guide_get_name (GTK_CONSTRAINT_GUIDE (orig));
+  else
+    {
+      g_warning ("Don't know how to handle %s targets", G_OBJECT_TYPE_NAME (orig));
+      return NULL;
+    }
+  for (i = 0; i < g_list_model_get_n_items (model); i++)
+    {
+      item = g_list_model_get_item (model, i);
+      g_object_unref (item);
+      if (GTK_IS_WIDGET (item))
+        model_name = gtk_widget_get_name (GTK_WIDGET (item));
+      else
+        model_name = gtk_constraint_guide_get_name (GTK_CONSTRAINT_GUIDE (item));
+
+      if (strcmp (name, model_name) == 0)
+        return GTK_CONSTRAINT_TARGET (item);
+    }
+  g_warning ("Failed to find target '%s'", name);
+
+  return NULL;
+}
+
+gboolean
+constraint_editor_window_load (ConstraintEditorWindow *self,
+                               GFile            *file)
+{
+  char *path;
+  GtkBuilder *builder;
+  GError *error = NULL;
+  GtkWidget *view;
+  GtkLayoutManager *layout;
+  GtkWidget *child;
+  const char *name;
+  gpointer item;
+  int i;
+  GListModel *list;
+
+  path = g_file_get_path (file);
+
+  builder = gtk_builder_new ();
+  if (!gtk_builder_add_from_file (builder, path, &error))
+    {
+      g_print ("Could not load %s: %s", path, error->message);
+      g_error_free (error);
+      g_free (path);
+      g_object_unref (builder);
+      return FALSE;
+    }
+
+  view = GTK_WIDGET (gtk_builder_get_object (builder, "view"));
+  if (!GTK_IS_BOX (view))
+    {
+      g_print ("Could not load %s: No GtkBox named 'view'", path);
+      g_free (path);
+      g_object_unref (builder);
+      return FALSE;
+    }
+  layout = gtk_widget_get_layout_manager (view);
+  if (!GTK_IS_CONSTRAINT_LAYOUT (layout))
+    {
+      g_print ("Could not load %s: Widget 'view' does not use GtkConstraintLayout", path);
+      g_free (path);
+      g_object_unref (builder);
+      return FALSE;
+    }
+
+  for (child = gtk_widget_get_first_child (view);
+       child;
+       child = gtk_widget_get_next_sibling (child))
+    {
+      if (!GTK_IS_LABEL (child))
+        {
+          g_print ("Skipping non-GtkLabel child\n");
+          continue;
+        }
+
+      name = gtk_label_get_label (GTK_LABEL (child));
+      constraint_view_add_child (CONSTRAINT_VIEW (self->view), name);
+    }
+
+  list = gtk_constraint_layout_observe_guides (GTK_CONSTRAINT_LAYOUT (layout));
+  for (i = 0; i < g_list_model_get_n_items (list); i++)
+    {
+      GtkConstraintGuide *guide, *clone;
+      int w, h;
+
+      item = g_list_model_get_item (list, i);
+      guide = GTK_CONSTRAINT_GUIDE (item);
+
+      /* need to clone here, to attach to the right targets */
+      clone = gtk_constraint_guide_new ();
+      gtk_constraint_guide_set_name (clone, gtk_constraint_guide_get_name (guide));
+      gtk_constraint_guide_set_strength (clone, gtk_constraint_guide_get_strength (guide));
+      gtk_constraint_guide_get_min_size (guide, &w, &h);
+      gtk_constraint_guide_set_min_size (clone, w, h);
+      gtk_constraint_guide_get_nat_size (guide, &w, &h);
+      gtk_constraint_guide_set_nat_size (clone, w, h);
+      gtk_constraint_guide_get_max_size (guide, &w, &h);
+      gtk_constraint_guide_set_max_size (clone, w, h);
+      constraint_view_add_guide (CONSTRAINT_VIEW (self->view), clone);
+      g_object_unref (guide);
+      g_object_unref (clone);
+    }
+  g_object_unref (list);
+
+  list = gtk_constraint_layout_observe_constraints (GTK_CONSTRAINT_LAYOUT (layout));
+  for (i = 0; i < g_list_model_get_n_items (list); i++)
+    {
+      GtkConstraint *constraint;
+      GtkConstraint *clone;
+      GtkConstraintTarget *target;
+      GtkConstraintTarget *source;
+      GtkConstraintAttribute source_attr;
+
+      item = g_list_model_get_item (list, i);
+      constraint = GTK_CONSTRAINT (item);
+
+      target = gtk_constraint_get_target (constraint);
+      source = gtk_constraint_get_source (constraint);
+      source_attr = gtk_constraint_get_source_attribute (constraint);
+
+      if (source == NULL && source_attr == GTK_CONSTRAINT_ATTRIBUTE_NONE)
+        clone = gtk_constraint_new_constant (find_target (constraint_view_get_model (CONSTRAINT_VIEW (self->view)), target),
+                                  gtk_constraint_get_target_attribute (constraint),
+                                  gtk_constraint_get_relation (constraint),
+                                  gtk_constraint_get_constant (constraint),
+                                  gtk_constraint_get_strength (constraint));
+      else
+        clone = gtk_constraint_new (find_target (constraint_view_get_model (CONSTRAINT_VIEW (self->view)), target),
+                                    gtk_constraint_get_target_attribute (constraint),
+                                    gtk_constraint_get_relation (constraint),
+                                    find_target (constraint_view_get_model (CONSTRAINT_VIEW (self->view)), source),
+                                    source_attr,
+                                    gtk_constraint_get_multiplier (constraint),
+                                    gtk_constraint_get_constant (constraint),
+                                    gtk_constraint_get_strength (constraint));
+
+      constraint_view_add_constraint (CONSTRAINT_VIEW (self->view), clone);
+
+      g_object_unref (constraint);
+      g_object_unref (clone);
+    }
+  g_object_unref (list);
+
+  g_free (path);
+  g_object_unref (builder);
+
+  return TRUE;
+}
+
+static void
+open_response_cb (GObject *source,
+                  GAsyncResult *result,
+                  void *user_data)
+{
+  GtkFileDialog *dialog = GTK_FILE_DIALOG (source);
+  ConstraintEditorWindow *self = user_data;
+  GFile *file;
+
+  file = gtk_file_dialog_open_finish (dialog, result, NULL);
+  if (file)
+    {
+      constraint_editor_window_load (self, file);
+      g_object_unref (file);
+    }
+}
+
+static void
+open_cb (GtkWidget              *button,
+         ConstraintEditorWindow *self)
+{
+  GtkFileDialog *dialog;
+  GFile *cwd;
+
+  dialog = gtk_file_dialog_new ();
+  gtk_file_dialog_set_title (dialog, "Open file");
+  cwd = g_file_new_for_path (".");
+  gtk_file_dialog_set_initial_folder (dialog, cwd);
+  g_object_unref (cwd);
+  gtk_file_dialog_open (dialog, GTK_WINDOW (self), NULL, open_response_cb, self);
+  g_object_unref (dialog);
+}
+
+static void
+serialize_child (GString   *str,
+                 int        indent,
+                 GtkWidget *child)
+{
+  const char *name;
+
+  name = gtk_widget_get_name (child);
+  g_string_append_printf (str, "%*s<child>\n", indent, "");
+  g_string_append_printf (str, "%*s  <object class=\"GtkLabel\" id=\"%s\">\n", indent, "", name);
+  g_string_append_printf (str, "%*s    <property name=\"label\">%s</property>\n", indent, "", name);
+  g_string_append_printf (str, "%*s  </object>\n", indent, "");
+  g_string_append_printf (str, "%*s</child>\n", indent, "");
+}
+
+static char *
+serialize_model (GListModel *list)
+{
+  GString *str = g_string_new ("");
+  int i;
+
+  g_string_append (str, "<interface>\n");
+  g_string_append (str, "  <object class=\"GtkBox\" id=\"view\">\n");
+  g_string_append (str, "    <property name=\"layout-manager\">\n");
+  g_string_append (str, "      <object class=\"GtkConstraintLayout\">\n");
+  g_string_append (str, "        <constraints>\n");
+  for (i = 0; i < g_list_model_get_n_items (list); i++)
+    {
+      gpointer item = g_list_model_get_item (list, i);
+      g_object_unref (item);
+      if (GTK_IS_CONSTRAINT (item))
+        constraint_editor_serialize_constraint (str, 10, GTK_CONSTRAINT (item));
+      else if (GTK_IS_CONSTRAINT_GUIDE (item))
+        guide_editor_serialize_guide (str, 10, GTK_CONSTRAINT_GUIDE (item));
+    }
+  g_string_append (str, "        </constraints>\n");
+  g_string_append (str, "      </object>\n");
+  g_string_append (str, "    </property>\n");
+  for (i = 0; i < g_list_model_get_n_items (list); i++)
+    {
+      gpointer item = g_list_model_get_item (list, i);
+      g_object_unref (item);
+      if (GTK_IS_WIDGET (item))
+        serialize_child (str, 4, GTK_WIDGET (item));
+    }
+  g_string_append (str, "  </object>\n");
+  g_string_append (str, "</interface>\n");
+
+  return g_string_free (str, FALSE);
+}
+
+
+static void
+save_response_cb (GObject *source,
+                  GAsyncResult *result,
+                  void *user_data)
+{
+  GtkFileDialog *dialog = GTK_FILE_DIALOG (source);
+  ConstraintEditorWindow *self = user_data;
+  GFile *file;
+
+  file = gtk_file_dialog_save_finish (dialog, result, NULL);
+  if (file)
+    {
+      GListModel *model;
+      char *text;
+      GError *error = NULL;
+
+      model = constraint_view_get_model (CONSTRAINT_VIEW (self->view));
+      text = serialize_model (model);
+      g_file_replace_contents (file, text, strlen (text),
+                               NULL, FALSE,
+                               G_FILE_CREATE_NONE,
+                               NULL,
+                               NULL,
+                               &error);
+      if (error != NULL)
+        {
+          GtkAlertDialog *alert;
+
+          alert = gtk_alert_dialog_new ("Saving failed");
+          gtk_alert_dialog_set_detail (alert, error->message);
+          gtk_alert_dialog_show (alert,
+                                 GTK_WINDOW (gtk_widget_get_root (GTK_WIDGET (self))));
+          g_object_unref (alert);
+          g_error_free (error);
+        }
+
+      g_free (text);
+      g_object_unref (file);
+    }
+}
+
+static void
+save_cb (GtkWidget              *button,
+         ConstraintEditorWindow *self)
+{
+  GtkFileDialog *dialog;
+  GFile *cwd;
+
+  dialog = gtk_file_dialog_new ();
+  gtk_file_dialog_set_title (dialog, "Save constraints");
+  cwd = g_file_new_for_path (".");
+  gtk_file_dialog_set_initial_folder (dialog, cwd);
+  g_object_unref (cwd);
+  gtk_file_dialog_save (dialog,
+                        GTK_WINDOW (gtk_widget_get_root (GTK_WIDGET (button))),
+                        NULL,
+                        save_response_cb, self);
+  g_object_unref (dialog);
+}
+
+static void
+constraint_editor_window_dispose (GObject *object)
+{
+  gtk_widget_dispose_template (GTK_WIDGET (object), CONSTRAINT_EDITOR_WINDOW_TYPE);
+
+  G_OBJECT_CLASS (constraint_editor_window_parent_class)->dispose (object);
+}
+
+static int child_counter;
+static int guide_counter;
+
+static void
+add_child (ConstraintEditorWindow *win)
+{
+  char *name;
+
+  child_counter++;
+  name = g_strdup_printf ("Child %d", child_counter);
+  constraint_view_add_child (CONSTRAINT_VIEW (win->view), name);
+  g_free (name);
+}
+
+static void
+add_guide (ConstraintEditorWindow *win)
+{
+  char *name;
+  GtkConstraintGuide *guide;
+
+  guide_counter++;
+  name = g_strdup_printf ("Guide %d", guide_counter);
+  guide = gtk_constraint_guide_new ();
+  gtk_constraint_guide_set_name (guide, name);
+  g_free (name);
+
+  constraint_view_add_guide (CONSTRAINT_VIEW (win->view), guide);
+}
+
+static void
+constraint_editor_done (ConstraintEditor *editor,
+                        GtkConstraint    *constraint,
+                        ConstraintEditorWindow *win)
+{
+  GtkConstraint *old_constraint;
+
+  g_object_get (editor, "constraint", &old_constraint, NULL);
+
+  if (old_constraint)
+    constraint_view_remove_constraint (CONSTRAINT_VIEW (win->view), old_constraint);
+
+  constraint_view_add_constraint (CONSTRAINT_VIEW (win->view), constraint);
+
+  g_clear_object (&old_constraint);
+
+  gtk_window_destroy (GTK_WINDOW (gtk_widget_get_ancestor (GTK_WIDGET (editor), GTK_TYPE_WINDOW)));
+}
+
+static void
+edit_constraint (ConstraintEditorWindow *win,
+                 GtkConstraint          *constraint)
+{
+  GtkWidget *window;
+  ConstraintEditor *editor;
+  GListModel *model;
+
+  window = gtk_window_new ();
+  gtk_window_set_transient_for (GTK_WINDOW (window), GTK_WINDOW (win));
+  gtk_window_set_resizable (GTK_WINDOW (window), FALSE);
+  if (constraint)
+    gtk_window_set_title (GTK_WINDOW (window), "Edit Constraint");
+  else
+    gtk_window_set_title (GTK_WINDOW (window), "Create Constraint");
+
+  model = constraint_view_get_model (CONSTRAINT_VIEW (win->view));
+
+  editor = constraint_editor_new (model, constraint);
+
+  gtk_window_set_child (GTK_WINDOW (window), GTK_WIDGET (editor));
+
+  g_signal_connect (editor, "done", G_CALLBACK (constraint_editor_done), win);
+
+  gtk_window_present (GTK_WINDOW (window));
+}
+
+static void
+add_constraint (ConstraintEditorWindow *win)
+{
+  edit_constraint (win, NULL);
+}
+
+static void
+guide_editor_done (GuideEditor            *editor,
+                   GtkConstraintGuide     *guide,
+                   ConstraintEditorWindow *win)
+{
+  gtk_window_destroy (GTK_WINDOW (gtk_widget_get_ancestor (GTK_WIDGET (editor), GTK_TYPE_WINDOW)));
+}
+
+static void
+edit_guide (ConstraintEditorWindow *win,
+            GtkConstraintGuide     *guide)
+{
+  GtkWidget *window;
+  GuideEditor *editor;
+
+  window = gtk_window_new ();
+  gtk_window_set_resizable (GTK_WINDOW (window), FALSE);
+  gtk_window_set_transient_for (GTK_WINDOW (window), GTK_WINDOW (win));
+  gtk_window_set_title (GTK_WINDOW (window), "Edit Guide");
+
+  editor = guide_editor_new (guide);
+  gtk_window_set_child (GTK_WINDOW (window), GTK_WIDGET (editor));
+
+  g_signal_connect (editor, "done", G_CALLBACK (guide_editor_done), win);
+  gtk_window_present (GTK_WINDOW (window));
+}
+
+static void
+row_activated (GtkListBox *list,
+               GtkListBoxRow *row,
+               ConstraintEditorWindow *win)
+{
+  GObject *item;
+
+  item = G_OBJECT (g_object_get_data (G_OBJECT (row), "item"));
+
+  if (GTK_IS_CONSTRAINT (item))
+    edit_constraint (win, GTK_CONSTRAINT (item));
+  else if (GTK_IS_CONSTRAINT_GUIDE (item))
+    edit_guide (win, GTK_CONSTRAINT_GUIDE (item));
+}
+
+static void
+constraint_editor_window_class_init (ConstraintEditorWindowClass *class)
+{
+  GObjectClass *object_class = G_OBJECT_CLASS (class);
+  GtkWidgetClass *widget_class = GTK_WIDGET_CLASS (class);
+
+  g_type_ensure (CONSTRAINT_VIEW_TYPE);
+
+  object_class->dispose = constraint_editor_window_dispose;
+
+  gtk_widget_class_set_template_from_resource (widget_class,
+                                               "/org/gtk/gtk4/constraint-editor/constraint-editor-window.ui");
+
+  gtk_widget_class_bind_template_child (widget_class, ConstraintEditorWindow, paned);
+  gtk_widget_class_bind_template_child (widget_class, ConstraintEditorWindow, view);
+  gtk_widget_class_bind_template_child (widget_class, ConstraintEditorWindow, list);
+
+  gtk_widget_class_bind_template_callback (widget_class, open_cb);
+  gtk_widget_class_bind_template_callback (widget_class, save_cb);
+  gtk_widget_class_bind_template_callback (widget_class, add_child);
+  gtk_widget_class_bind_template_callback (widget_class, add_guide);
+  gtk_widget_class_bind_template_callback (widget_class, add_constraint);
+  gtk_widget_class_bind_template_callback (widget_class, row_activated);
+}
+
+static void
+row_edit (GtkButton *button,
+          ConstraintEditorWindow *win)
+{
+  GtkWidget *row;
+  GObject *item;
+
+  row = gtk_widget_get_ancestor (GTK_WIDGET (button), GTK_TYPE_LIST_BOX_ROW);
+  item = (GObject *)g_object_get_data (G_OBJECT (row), "item");
+  if (GTK_IS_CONSTRAINT (item))
+    edit_constraint (win, GTK_CONSTRAINT (item));
+  else if (GTK_IS_CONSTRAINT_GUIDE (item))
+    edit_guide (win, GTK_CONSTRAINT_GUIDE (item));
+}
+
+static void
+mark_constraints_invalid (ConstraintEditorWindow *win,
+                          gpointer                removed)
+{
+  GtkWidget *child;
+  GObject *item;
+
+  for (child = gtk_widget_get_first_child (win->list);
+       child;
+       child = gtk_widget_get_next_sibling (child))
+    {
+      item = (GObject *)g_object_get_data (G_OBJECT (child), "item");
+      if (GTK_IS_CONSTRAINT (item))
+        {
+          GtkConstraint *constraint = GTK_CONSTRAINT (item);
+
+          if (gtk_constraint_get_target (constraint) == (GtkConstraintTarget *)removed ||
+              gtk_constraint_get_source (constraint) == (GtkConstraintTarget *)removed)
+            {
+              GtkWidget *button;
+              button = (GtkWidget *)g_object_get_data (G_OBJECT (child), "edit");
+              gtk_button_set_icon_name (GTK_BUTTON (button), "dialog-warning-symbolic");
+              gtk_widget_set_tooltip_text (button, "Constraint is invalid");
+            }
+        }
+    }
+}
+
+static void
+row_delete (GtkButton *button,
+            ConstraintEditorWindow *win)
+{
+  GtkWidget *row;
+  GObject *item;
+
+  row = gtk_widget_get_ancestor (GTK_WIDGET (button), GTK_TYPE_LIST_BOX_ROW);
+  item = (GObject *)g_object_get_data (G_OBJECT (row), "item");
+  if (GTK_IS_CONSTRAINT (item))
+    constraint_view_remove_constraint (CONSTRAINT_VIEW (win->view),
+                                       GTK_CONSTRAINT (item));
+  else if (GTK_IS_CONSTRAINT_GUIDE (item))
+    {
+      mark_constraints_invalid (win, item);
+      constraint_view_remove_guide (CONSTRAINT_VIEW (win->view),
+                                    GTK_CONSTRAINT_GUIDE (item));
+    }
+  else if (GTK_IS_WIDGET (item))
+    {
+      mark_constraints_invalid (win, item);
+      constraint_view_remove_child (CONSTRAINT_VIEW (win->view),
+                                    GTK_WIDGET (item));
+    }
+}
+
+static GtkWidget *
+create_widget_func (gpointer item,
+                    gpointer user_data)
+{
+  ConstraintEditorWindow *win = user_data;
+  const char *name;
+  char *freeme = NULL;
+  GtkWidget *row, *box, *label, *button;
+
+  if (GTK_IS_WIDGET (item))
+    name = gtk_widget_get_name (GTK_WIDGET (item));
+  else if (GTK_IS_CONSTRAINT_GUIDE (item))
+    name = gtk_constraint_guide_get_name (GTK_CONSTRAINT_GUIDE (item));
+  else if (GTK_IS_CONSTRAINT (item))
+    name = freeme = constraint_editor_constraint_to_string (GTK_CONSTRAINT (item));
+  else
+    name = "";
+
+  row = gtk_list_box_row_new ();
+  g_object_set_data_full (G_OBJECT (row), "item", g_object_ref (item), g_object_unref);
+  box = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 0);
+  label = gtk_label_new (name);
+  if (GTK_IS_WIDGET (item) || GTK_IS_CONSTRAINT_GUIDE (item))
+    g_object_bind_property (item, "name",
+                            label, "label",
+                            G_BINDING_DEFAULT);
+  gtk_widget_set_margin_start (label, 10);
+  gtk_widget_set_margin_end (label, 10);
+  gtk_widget_set_margin_top (label, 10);
+  gtk_widget_set_margin_bottom (label, 10);
+  gtk_label_set_xalign (GTK_LABEL (label), 0.0);
+  gtk_widget_set_hexpand (label, TRUE);
+  gtk_list_box_row_set_child (GTK_LIST_BOX_ROW (row), box);
+  gtk_box_append (GTK_BOX (box), label);
+
+  if (GTK_IS_CONSTRAINT (item) || GTK_IS_CONSTRAINT_GUIDE (item))
+    {
+      button = gtk_button_new_from_icon_name ("document-edit-symbolic");
+      gtk_button_set_has_frame (GTK_BUTTON (button), FALSE);
+      g_signal_connect (button, "clicked", G_CALLBACK (row_edit), win);
+      g_object_set_data (G_OBJECT (row), "edit", button);
+      gtk_box_append (GTK_BOX (box), button);
+      button = gtk_button_new_from_icon_name ("edit-delete-symbolic");
+      gtk_button_set_has_frame (GTK_BUTTON (button), FALSE);
+      g_signal_connect (button, "clicked", G_CALLBACK (row_delete), win);
+      gtk_box_append (GTK_BOX (box), button);
+    }
+  else if (GTK_IS_WIDGET (item))
+    {
+      button = gtk_button_new_from_icon_name ("edit-delete-symbolic");
+      gtk_button_set_has_frame (GTK_BUTTON (button), FALSE);
+      g_signal_connect (button, "clicked", G_CALLBACK (row_delete), win);
+      gtk_box_append (GTK_BOX (box), button);
+    }
+
+  g_free (freeme);
+
+  return row;
+}
+
+static void
+constraint_editor_window_init (ConstraintEditorWindow *self)
+{
+  gtk_widget_init_template (GTK_WIDGET (self));
+
+  gtk_list_box_bind_model (GTK_LIST_BOX (self->list),
+                           constraint_view_get_model (CONSTRAINT_VIEW (self->view)),
+                           create_widget_func,
+                           self,
+                           NULL);
+}
+
+ConstraintEditorWindow *
+constraint_editor_window_new (ConstraintEditorApplication *application)
+{
+  return g_object_new (CONSTRAINT_EDITOR_WINDOW_TYPE,
+                       "application", application,
+                       NULL);
+}

demos/constraint-editor/constraint-editor-window.h

@@ -0,0 +1,34 @@
+/*
+ * Copyright © 2019 Red Hat, Inc
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library. If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Authors: Matthias Clasen
+ */
+
+#pragma once
+
+#include <gtk/gtk.h>
+
+#include "constraint-editor-application.h"
+
+
+#define CONSTRAINT_EDITOR_WINDOW_TYPE (constraint_editor_window_get_type ())
+
+G_DECLARE_FINAL_TYPE (ConstraintEditorWindow, constraint_editor_window, CONSTRAINT, EDITOR_WINDOW, GtkApplicationWindow)
+
+ConstraintEditorWindow * constraint_editor_window_new  (ConstraintEditorApplication  *application);
+
+gboolean                 constraint_editor_window_load (ConstraintEditorWindow       *self,
+                                                        GFile                        *file);

demos/constraint-editor/constraint-editor-window.ui

@@ -0,0 +1,77 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<interface>
+  <template class="ConstraintEditorWindow" parent="GtkApplicationWindow">
+    <property name="title" translatable="yes">GTK Constraint Editor</property>
+    <property name="default-width">1024</property>
+    <property name="default-height">768</property>
+    <child type="titlebar">
+      <object class="GtkHeaderBar" id="header">
+        <child type="start">
+          <object class="GtkButton">
+            <property name="icon-name">document-open-symbolic</property>
+            <property name="tooltip-text">Open ui file</property>
+            <signal name="clicked" handler="open_cb"/>
+          </object>
+        </child>
+        <child type="start">
+          <object class="GtkButton">
+            <property name="icon-name">document-save-symbolic</property>
+            <property name="tooltip-text">Save to ui file</property>
+            <signal name="clicked" handler="save_cb"/>
+          </object>
+        </child>
+      </object>
+    </child>
+    <child>
+      <object class="GtkPaned" id="paned">
+        <property name="orientation">horizontal</property>
+        <child>
+          <object class="GtkBox">
+            <property name="orientation">vertical</property>
+            <child>
+              <object class="GtkBox">
+                <property name="orientation">horizontal</property>
+                <child>
+                  <object class="GtkButton">
+                    <property name="label">Add Child</property>
+                    <signal name="clicked" handler="add_child" swapped="yes"/>
+                  </object>
+                </child>
+                <child>
+                  <object class="GtkButton">
+                    <property name="label">Add Guide</property>
+                    <signal name="clicked" handler="add_guide" swapped="yes"/>
+                  </object>
+                </child>
+                <child>
+                  <object class="GtkButton">
+                    <property name="label">Add Constraint</property>
+                    <signal name="clicked" handler="add_constraint" swapped="yes"/>
+                  </object>
+                </child>
+              </object>
+            </child>
+            <child>
+              <object class="GtkScrolledWindow">
+                <property name="hscrollbar-policy">never</property>
+                <property name="vscrollbar-policy">automatic</property>
+                <property name="vexpand">1</property>
+                <child>
+                  <object class="GtkListBox" id="list">
+                    <property name="show-separators">1</property>
+                    <property name="selection-mode">none</property>
+                    <signal name="row-activated" handler="row_activated"/>
+                  </object>
+                </child>
+              </object>
+            </child>
+          </object>
+        </child>
+        <child>
+          <object class="ConstraintView" id="view">
+          </object>
+        </child>
+      </object>
+    </child>
+  </template>
+</interface>

demos/constraint-editor/constraint-editor.c

@@ -0,0 +1,716 @@
+/*
+ * Copyright © 2019 Red Hat, Inc.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library. If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Authors: Matthias Clasen
+ */
+
+#include "config.h"
+
+#include "constraint-editor.h"
+#include "constraint-view.h"
+
+struct _ConstraintEditor
+{
+  GtkWidget parent_instance;
+
+  GtkWidget *grid;
+  GtkWidget *target;
+  GtkWidget *target_attr;
+  GtkWidget *relation;
+  GtkWidget *source;
+  GtkWidget *source_attr;
+  GtkWidget *multiplier;
+  GtkWidget *constant;
+  GtkWidget *strength;
+  GtkWidget *preview;
+  GtkWidget *button;
+
+  GtkConstraint *constraint;
+  GListModel *model;
+
+  gboolean constructed;
+};
+
+enum {
+  PROP_MODEL = 1,
+  PROP_CONSTRAINT,
+  LAST_PROP
+};
+
+static GParamSpec *pspecs[LAST_PROP];
+
+enum {
+  DONE,
+  LAST_SIGNAL
+};
+
+static guint signals[LAST_SIGNAL];
+
+G_DEFINE_TYPE(ConstraintEditor, constraint_editor, GTK_TYPE_WIDGET);
+
+static const char *
+get_target_name (GtkConstraintTarget *target)
+{
+  if (target == NULL)
+    return "Super";
+  else if (GTK_IS_WIDGET (target))
+    return gtk_widget_get_name (GTK_WIDGET (target));
+  else if (GTK_IS_CONSTRAINT_GUIDE (target))
+    return gtk_constraint_guide_get_name (GTK_CONSTRAINT_GUIDE (target));
+  else
+    return "";
+}
+
+static void
+constraint_target_combo (GListModel *model,
+                         GtkWidget  *combo,
+                         gboolean    is_source)
+{
+  GtkStringList *targets;
+  int i;
+
+  targets = gtk_string_list_new (NULL);
+
+  gtk_string_list_append (targets, "Super");
+
+  if (model)
+    {
+      for (i = 0; i < g_list_model_get_n_items (model); i++)
+        {
+          GObject *item = g_list_model_get_object (model, i);
+
+          if (GTK_IS_CONSTRAINT (item))
+            continue;
+
+          gtk_string_list_append (targets, get_target_name (GTK_CONSTRAINT_TARGET (item)));
+          g_object_unref (item);
+        }
+    }
+
+  gtk_drop_down_set_model (GTK_DROP_DOWN (combo), G_LIST_MODEL (targets));
+  g_object_unref (targets);
+}
+
+static gpointer
+get_target (GListModel *model,
+            const char *id)
+{
+  int i;
+
+  if (id == NULL)
+    return NULL;
+
+  if (strcmp ("Super", id) == 0)
+    return NULL;
+
+  for (i = 0; i < g_list_model_get_n_items (model); i++)
+    {
+      GObject *item = g_list_model_get_object (model, i);
+      g_object_unref (item);
+      if (GTK_IS_CONSTRAINT (item))
+        continue;
+      else if (GTK_IS_WIDGET (item))
+        {
+          if (strcmp (id, gtk_widget_get_name (GTK_WIDGET (item))) == 0)
+            return item;
+        }
+      else if (GTK_IS_CONSTRAINT_GUIDE (item))
+        {
+          if (strcmp (id, gtk_constraint_guide_get_name (GTK_CONSTRAINT_GUIDE (item))) == 0)
+            return item;
+        }
+    }
+
+  return NULL;
+}
+
+static void
+select_target (GtkDropDown *combo,
+               const char  *target_name)
+{
+  GListModel *model = gtk_drop_down_get_model (combo);
+
+  for (unsigned int i = 0; i < g_list_model_get_n_items (model); i++)
+    {
+      GtkStringObject *s = g_list_model_get_item (model, i);
+
+      g_object_unref (s);
+      if (strcmp (target_name, gtk_string_object_get_string (s)) == 0)
+        {
+          gtk_drop_down_set_selected (GTK_DROP_DOWN (combo), i);
+          return;
+        }
+    }
+}
+
+static GtkConstraintAttribute
+get_attr (unsigned int id)
+{
+  switch (id)
+    {
+    case 0: return GTK_CONSTRAINT_ATTRIBUTE_NONE;
+    case 1: return GTK_CONSTRAINT_ATTRIBUTE_LEFT;
+    case 2: return GTK_CONSTRAINT_ATTRIBUTE_RIGHT;
+    case 3: return GTK_CONSTRAINT_ATTRIBUTE_TOP;
+    case 4: return GTK_CONSTRAINT_ATTRIBUTE_BOTTOM;
+    case 5: return GTK_CONSTRAINT_ATTRIBUTE_START;
+    case 6: return GTK_CONSTRAINT_ATTRIBUTE_END;
+    case 7: return GTK_CONSTRAINT_ATTRIBUTE_WIDTH;
+    case 8: return GTK_CONSTRAINT_ATTRIBUTE_HEIGHT;
+    case 9: return GTK_CONSTRAINT_ATTRIBUTE_CENTER_X;
+    case 10: return GTK_CONSTRAINT_ATTRIBUTE_CENTER_Y;
+    case 11: return GTK_CONSTRAINT_ATTRIBUTE_BASELINE;
+    default: g_assert_not_reached ();
+    }
+}
+
+static unsigned int
+get_attr_id (GtkConstraintAttribute attr)
+{
+  switch (attr)
+    {
+    case GTK_CONSTRAINT_ATTRIBUTE_NONE: return 0;
+    case GTK_CONSTRAINT_ATTRIBUTE_LEFT: return 1;
+    case GTK_CONSTRAINT_ATTRIBUTE_RIGHT: return 2;
+    case GTK_CONSTRAINT_ATTRIBUTE_TOP: return 3;
+    case GTK_CONSTRAINT_ATTRIBUTE_BOTTOM: return 4;
+    case GTK_CONSTRAINT_ATTRIBUTE_START: return 5;
+    case GTK_CONSTRAINT_ATTRIBUTE_END: return 6;
+    case GTK_CONSTRAINT_ATTRIBUTE_WIDTH: return 7;
+    case GTK_CONSTRAINT_ATTRIBUTE_HEIGHT: return 8;
+    case GTK_CONSTRAINT_ATTRIBUTE_CENTER_X: return 9;
+    case GTK_CONSTRAINT_ATTRIBUTE_CENTER_Y: return 10;
+    case GTK_CONSTRAINT_ATTRIBUTE_BASELINE: return 11;
+    default: g_assert_not_reached ();
+    }
+}
+
+static const char *
+get_attr_nick (GtkConstraintAttribute attr)
+{
+  GEnumClass *class = g_type_class_ref (GTK_TYPE_CONSTRAINT_ATTRIBUTE);
+  GEnumValue *value = g_enum_get_value (class, attr);
+  const char *nick = value->value_nick;
+  g_type_class_unref (class);
+
+  return nick;
+}
+
+static GtkConstraintRelation
+get_relation (unsigned int id)
+{
+  switch (id)
+    {
+    case 0: return GTK_CONSTRAINT_RELATION_LE;
+    case 1: return GTK_CONSTRAINT_RELATION_EQ;
+    case 2: return GTK_CONSTRAINT_RELATION_GE;
+    default: g_assert_not_reached ();
+    }
+}
+
+static unsigned int
+get_relation_id (GtkConstraintRelation relation)
+{
+  switch (relation)
+    {
+    case GTK_CONSTRAINT_RELATION_LE: return 0;
+    case GTK_CONSTRAINT_RELATION_EQ: return 1;
+    case GTK_CONSTRAINT_RELATION_GE: return 2;
+    default: g_assert_not_reached ();
+    }
+}
+
+static const char *
+get_relation_nick (GtkConstraintRelation relation)
+{
+  GEnumClass *class = g_type_class_ref (GTK_TYPE_CONSTRAINT_RELATION);
+  GEnumValue *value = g_enum_get_value (class, relation);
+  const char *nick = value->value_nick;
+  g_type_class_unref (class);
+
+  return nick;
+}
+
+static const char *
+get_relation_display_name (GtkConstraintRelation relation)
+{
+  switch (relation)
+    {
+    case GTK_CONSTRAINT_RELATION_LE:
+      return "≤";
+    case GTK_CONSTRAINT_RELATION_EQ:
+      return "=";
+    case GTK_CONSTRAINT_RELATION_GE:
+      return "≥";
+    default:
+      return "?";
+    }
+}
+
+static GtkConstraintStrength
+get_strength (unsigned int id)
+{ 
+  switch (id)
+    {
+    case 0: return GTK_CONSTRAINT_STRENGTH_WEAK;
+    case 1: return GTK_CONSTRAINT_STRENGTH_MEDIUM;
+    case 2: return GTK_CONSTRAINT_STRENGTH_STRONG;
+    case 3: return GTK_CONSTRAINT_STRENGTH_REQUIRED;
+    default: g_assert_not_reached ();
+    }
+}
+
+static unsigned int
+get_strength_id (GtkConstraintStrength strength)
+{
+  switch (strength)
+    {
+    case GTK_CONSTRAINT_STRENGTH_WEAK: return 0;
+    case GTK_CONSTRAINT_STRENGTH_MEDIUM: return 1;
+    case GTK_CONSTRAINT_STRENGTH_STRONG: return 2;
+    case GTK_CONSTRAINT_STRENGTH_REQUIRED: return 3;
+    default: g_assert_not_reached ();
+    }
+}
+
+static const char *
+get_strength_nick (GtkConstraintStrength strength)
+{
+  GEnumClass *class = g_type_class_ref (GTK_TYPE_CONSTRAINT_STRENGTH);
+  GEnumValue *value = g_enum_get_value (class, strength);
+  const char *nick = value->value_nick;
+  g_type_class_unref (class);
+
+  return nick;
+}
+
+void
+constraint_editor_serialize_constraint (GString       *str,
+                                        int            indent,
+                                        GtkConstraint *constraint)
+{
+  const char *target;
+  const char *target_attr;
+  const char *relation;
+  const char *source;
+  const char *source_attr;
+  double multiplier;
+  double constant;
+  const char *strength;
+
+  target = get_target_name (gtk_constraint_get_target (constraint));
+  target_attr = get_attr_nick (gtk_constraint_get_target_attribute (constraint));
+  relation = get_relation_nick (gtk_constraint_get_relation (constraint));
+  source = get_target_name (gtk_constraint_get_source (constraint));
+  source_attr = get_attr_nick (gtk_constraint_get_source_attribute (constraint));
+  multiplier = gtk_constraint_get_multiplier (constraint);
+  constant = gtk_constraint_get_constant (constraint);
+  strength = get_strength_nick (gtk_constraint_get_strength (constraint));
+
+  g_string_append_printf (str, "%*s<constraint target=\"%s\" target-attribute=\"%s\"\n", indent, "", target, target_attr);
+  g_string_append_printf (str, "%*s            relation=\"%s\"\n", indent, "", relation);
+  if (strcmp (source_attr, "none") != 0)
+    {
+      g_string_append_printf (str, "%*s            source=\"%s\" source-attribute=\"%s\"\n", indent, "", source, source_attr);
+      g_string_append_printf (str, "%*s            multiplier=\"%g\"\n", indent, "", multiplier);
+    }
+  g_string_append_printf (str, "%*s            constant=\"%g\"\n", indent, "", constant);
+  g_string_append_printf (str, "%*s            strength=\"%s\" />\n", indent, "", strength);
+}
+
+static void
+create_constraint (GtkButton        *button,
+                   ConstraintEditor *editor)
+{
+  gpointer obj;
+  gpointer target;
+  GtkConstraintAttribute target_attr;
+  gpointer source;
+  GtkConstraintAttribute source_attr;
+  GtkConstraintRelation relation;
+  double multiplier;
+  double constant;
+  int strength;
+  GtkConstraint *constraint;
+
+  obj = gtk_drop_down_get_selected_item (GTK_DROP_DOWN (editor->target));
+  if (obj)
+    target = get_target (editor->model, gtk_string_object_get_string (GTK_STRING_OBJECT (obj)));
+  else
+    target = NULL;
+  target_attr = get_attr (gtk_drop_down_get_selected (GTK_DROP_DOWN (editor->target_attr)));
+
+  obj = gtk_drop_down_get_selected_item (GTK_DROP_DOWN (editor->source));
+  if (obj)
+    source = get_target (editor->model, gtk_string_object_get_string (GTK_STRING_OBJECT (obj)));
+  else
+    source = NULL;
+  source_attr = get_attr (gtk_drop_down_get_selected (GTK_DROP_DOWN(editor->source_attr)));
+
+  relation = get_relation (gtk_drop_down_get_selected (GTK_DROP_DOWN (editor->relation)));
+
+  multiplier = g_ascii_strtod (gtk_editable_get_text (GTK_EDITABLE (editor->multiplier)), NULL);
+
+  constant = g_ascii_strtod (gtk_editable_get_text (GTK_EDITABLE (editor->constant)), NULL);
+
+  strength = get_strength (gtk_drop_down_get_selected (GTK_DROP_DOWN (editor->strength)));
+
+  constraint = gtk_constraint_new (target, target_attr,
+                                   relation,
+                                   source, source_attr,
+                                   multiplier,
+                                   constant,
+                                   strength);
+  g_signal_emit (editor, signals[DONE], 0, constraint);
+  g_object_unref (constraint);
+}
+
+static void
+source_attr_changed (ConstraintEditor *editor)
+{
+  if (get_attr (gtk_drop_down_get_selected (GTK_DROP_DOWN (editor->source_attr))) == GTK_CONSTRAINT_ATTRIBUTE_NONE)
+    {
+      gtk_drop_down_set_selected (GTK_DROP_DOWN (editor->source), GTK_INVALID_LIST_POSITION);
+      gtk_editable_set_text (GTK_EDITABLE (editor->multiplier), "");
+      gtk_widget_set_sensitive (editor->source, FALSE);
+      gtk_widget_set_sensitive (editor->multiplier, FALSE);
+    }
+  else
+    {
+      gtk_widget_set_sensitive (editor->source, TRUE);
+      gtk_widget_set_sensitive (editor->multiplier, TRUE);
+      gtk_editable_set_text (GTK_EDITABLE (editor->multiplier), "1");
+    }
+}
+
+char *
+constraint_editor_constraint_to_string (GtkConstraint *constraint)
+{
+  GString *str;
+  const char *name;
+  const char *attr;
+  const char *relation;
+  double c, m;
+
+  str = g_string_new ("");
+
+  name = get_target_name (gtk_constraint_get_target (constraint));
+  attr = get_attr_nick (gtk_constraint_get_target_attribute (constraint));
+  relation = get_relation_display_name (gtk_constraint_get_relation (constraint));
+
+  if (name == NULL)
+    name = "[ ]";
+
+  g_string_append_printf (str, "%s.%s %s ", name, attr, relation);
+
+  c = gtk_constraint_get_constant (constraint);
+
+  attr = get_attr_nick (gtk_constraint_get_source_attribute (constraint));
+  if (strcmp (attr, "none") != 0)
+    {
+      name = get_target_name (gtk_constraint_get_source (constraint));
+      m = gtk_constraint_get_multiplier (constraint);
+
+      if (name == NULL)
+        name = "[ ]";
+
+      g_string_append_printf (str, "%s.%s", name, attr);
+
+      if (m != 1.0)
+        g_string_append_printf (str, " × %g", m);
+
+      if (c > 0.0)
+        g_string_append_printf (str, " + %g", c);
+      else if (c < 0.0)
+        g_string_append_printf (str, " - %g", -c);
+    }
+  else
+    g_string_append_printf (str, "%g", c);
+
+  return g_string_free (str, FALSE);
+}
+
+static void
+update_preview (ConstraintEditor *editor)
+{
+  GString *str;
+  const char *name;
+  const char *attr;
+  const char *relation;
+  const char *multiplier;
+  const char *constant;
+  double c, m;
+
+  if (!editor->constructed)
+    return;
+
+  str = g_string_new ("");
+
+  name = gtk_string_object_get_string (GTK_STRING_OBJECT (gtk_drop_down_get_selected_item (GTK_DROP_DOWN (editor->target))));
+  attr = get_attr_nick (get_attr (gtk_drop_down_get_selected ((GTK_DROP_DOWN (editor->target_attr)))));
+  relation = get_relation_nick (get_relation (gtk_drop_down_get_selected (GTK_DROP_DOWN (editor->relation))));
+
+  if (name == NULL)
+    name = "[ ]";
+
+  g_string_append_printf (str, "%s.%s %s ", name, attr, relation);
+
+  constant = gtk_editable_get_text (GTK_EDITABLE (editor->constant));
+  c = g_ascii_strtod (constant, NULL);
+
+  attr = get_attr_nick (get_attr (gtk_drop_down_get_selected (GTK_DROP_DOWN (editor->source_attr))));
+  if (strcmp (attr, "none") != 0)
+    {
+       name = gtk_string_object_get_string (GTK_STRING_OBJECT (gtk_drop_down_get_selected_item (GTK_DROP_DOWN (editor->source))));
+      multiplier = gtk_editable_get_text (GTK_EDITABLE (editor->multiplier));
+      m = g_ascii_strtod (multiplier, NULL);
+
+      if (name == NULL)
+        name = "[ ]";
+
+      g_string_append_printf (str, "%s.%s", name, attr);
+
+      if (m != 1.0)
+        g_string_append_printf (str, " × %g", m);
+
+      if (c > 0.0)
+        g_string_append_printf (str, " + %g", c);
+      else if (c < 0.0)
+        g_string_append_printf (str, " - %g", -c);
+    }
+  else
+    g_string_append_printf (str, "%g", c);
+
+  gtk_label_set_label (GTK_LABEL (editor->preview), str->str);
+
+  g_string_free (str, TRUE);
+}
+
+static void
+update_button (ConstraintEditor *editor)
+{
+  gpointer obj;
+  const char *target;
+  const char *source;
+  GtkConstraintAttribute source_attr = get_attr (gtk_drop_down_get_selected (GTK_DROP_DOWN (editor->source_attr)));
+
+  obj = gtk_drop_down_get_selected_item (GTK_DROP_DOWN (editor->target));
+  target = obj ? gtk_string_object_get_string (GTK_STRING_OBJECT (obj)) : NULL;
+
+  obj = gtk_drop_down_get_selected_item (GTK_DROP_DOWN (editor->source));
+  source = obj ?  gtk_string_object_get_string (GTK_STRING_OBJECT (obj)) : NULL;
+
+  if (target && (source || (source_attr == GTK_CONSTRAINT_ATTRIBUTE_NONE)))
+    gtk_widget_set_sensitive (editor->button, TRUE);
+  else
+    gtk_widget_set_sensitive (editor->button, FALSE);
+}
+
+static void
+constraint_editor_init (ConstraintEditor *editor)
+{
+  gtk_widget_init_template (GTK_WIDGET (editor));
+}
+
+static void
+constraint_editor_constructed (GObject *object)
+{
+  ConstraintEditor *editor = CONSTRAINT_EDITOR (object);
+
+  constraint_target_combo (editor->model, editor->target, FALSE);
+  constraint_target_combo (editor->model, editor->source, TRUE);
+
+  if (editor->constraint)
+    {
+      GtkConstraintTarget *target;
+      GtkConstraintAttribute attr;
+      GtkConstraintRelation relation;
+      GtkConstraintStrength strength;
+      char *val;
+      double multiplier;
+      double constant;
+
+      target = gtk_constraint_get_target (editor->constraint);
+      select_target (GTK_DROP_DOWN (editor->target), get_target_name (target));
+
+      attr = gtk_constraint_get_target_attribute (editor->constraint);
+      gtk_drop_down_set_selected (GTK_DROP_DOWN (editor->target_attr), get_attr_id (attr));
+
+      target = gtk_constraint_get_source (editor->constraint);
+      select_target (GTK_DROP_DOWN (editor->source), get_target_name (target));
+
+      attr = gtk_constraint_get_source_attribute (editor->constraint);
+      gtk_drop_down_set_selected (GTK_DROP_DOWN (editor->source_attr), get_attr_id (attr));
+
+      relation = gtk_constraint_get_relation (editor->constraint);
+      gtk_drop_down_set_selected (GTK_DROP_DOWN (editor->relation), get_relation_id (relation));
+
+      multiplier = gtk_constraint_get_multiplier (editor->constraint);
+      val = g_strdup_printf ("%g", multiplier);
+      gtk_editable_set_text (GTK_EDITABLE (editor->multiplier), val);
+      g_free (val);
+
+      constant = gtk_constraint_get_constant (editor->constraint);
+      val = g_strdup_printf ("%g", constant);
+      gtk_editable_set_text (GTK_EDITABLE (editor->constant), val);
+      g_free (val);
+
+      strength = gtk_constraint_get_strength (editor->constraint);
+      gtk_drop_down_set_selected (GTK_DROP_DOWN (editor->strength), get_strength_id (strength));
+
+      gtk_button_set_label (GTK_BUTTON (editor->button), "Apply");
+    }
+  else
+    {
+      gtk_drop_down_set_selected (GTK_DROP_DOWN (editor->target_attr), get_attr_id (GTK_CONSTRAINT_ATTRIBUTE_LEFT));
+      gtk_drop_down_set_selected (GTK_DROP_DOWN (editor->source_attr), get_attr_id (GTK_CONSTRAINT_ATTRIBUTE_LEFT));
+      gtk_drop_down_set_selected (GTK_DROP_DOWN (editor->relation), get_relation_id (GTK_CONSTRAINT_RELATION_EQ));
+      gtk_drop_down_set_selected (GTK_DROP_DOWN (editor->strength), get_strength_id (GTK_CONSTRAINT_STRENGTH_REQUIRED));
+
+      gtk_editable_set_text (GTK_EDITABLE (editor->multiplier), "1.0");
+      gtk_editable_set_text (GTK_EDITABLE (editor->constant), "0.0");
+
+      gtk_button_set_label (GTK_BUTTON (editor->button), "Create");
+    }
+
+  editor->constructed = TRUE;
+  update_preview (editor);
+  update_button (editor);
+}
+
+static void
+constraint_editor_set_property (GObject      *object,
+                                guint         property_id,
+                                const GValue *value,
+                                GParamSpec   *pspec)
+{
+  ConstraintEditor *self = CONSTRAINT_EDITOR (object);
+
+  switch (property_id)
+    {
+    case PROP_MODEL:
+      self->model = g_value_dup_object (value);
+      break;
+
+    case PROP_CONSTRAINT:
+      self->constraint = g_value_dup_object (value);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+    }
+}
+
+static void
+constraint_editor_get_property (GObject    *object,
+                                guint       property_id,
+                                GValue     *value,
+                                GParamSpec *pspec)
+{
+  ConstraintEditor *self = CONSTRAINT_EDITOR (object);
+
+  switch (property_id)
+    {
+    case PROP_MODEL:
+      g_value_set_object (value, self->model);
+      break;
+
+    case PROP_CONSTRAINT:
+      g_value_set_object (value, self->constraint);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+    }
+}
+
+static void
+constraint_editor_dispose (GObject *object)
+{
+  ConstraintEditor *self = (ConstraintEditor *)object;
+
+  g_clear_object (&self->model);
+  g_clear_object (&self->constraint);
+
+  gtk_widget_dispose_template (GTK_WIDGET (object), CONSTRAINT_EDITOR_TYPE);
+
+  G_OBJECT_CLASS (constraint_editor_parent_class)->dispose (object);
+}
+
+static void
+constraint_editor_class_init (ConstraintEditorClass *class)
+{
+  GObjectClass *object_class = G_OBJECT_CLASS (class);
+  GtkWidgetClass *widget_class = GTK_WIDGET_CLASS (class);
+
+  object_class->constructed = constraint_editor_constructed;
+  object_class->dispose = constraint_editor_dispose;
+  object_class->set_property = constraint_editor_set_property;
+  object_class->get_property = constraint_editor_get_property;
+
+  pspecs[PROP_CONSTRAINT] =
+    g_param_spec_object ("constraint", "constraint", "constraint",
+                         GTK_TYPE_CONSTRAINT,
+                         G_PARAM_READWRITE|G_PARAM_CONSTRUCT_ONLY);
+
+  pspecs[PROP_MODEL] =
+    g_param_spec_object ("model", "model", "model",
+                         G_TYPE_LIST_MODEL,
+                         G_PARAM_READWRITE|G_PARAM_CONSTRUCT_ONLY);
+
+  g_object_class_install_properties (object_class, LAST_PROP, pspecs);
+
+  signals[DONE] =
+    g_signal_new ("done",
+                  G_TYPE_FROM_CLASS (object_class),
+                  G_SIGNAL_RUN_LAST,
+                  0,
+                  NULL, NULL,
+                  NULL,
+                  G_TYPE_NONE, 1, GTK_TYPE_CONSTRAINT);
+
+  gtk_widget_class_set_layout_manager_type (widget_class, GTK_TYPE_BIN_LAYOUT);
+
+  gtk_widget_class_set_template_from_resource (widget_class,
+                                               "/org/gtk/gtk4/constraint-editor/constraint-editor.ui");
+
+  gtk_widget_class_bind_template_child (widget_class, ConstraintEditor, grid);
+  gtk_widget_class_bind_template_child (widget_class, ConstraintEditor, target);
+  gtk_widget_class_bind_template_child (widget_class, ConstraintEditor, target_attr);
+  gtk_widget_class_bind_template_child (widget_class, ConstraintEditor, relation);
+  gtk_widget_class_bind_template_child (widget_class, ConstraintEditor, source);
+  gtk_widget_class_bind_template_child (widget_class, ConstraintEditor, source_attr);
+  gtk_widget_class_bind_template_child (widget_class, ConstraintEditor, multiplier);
+  gtk_widget_class_bind_template_child (widget_class, ConstraintEditor, constant);
+  gtk_widget_class_bind_template_child (widget_class, ConstraintEditor, strength);
+  gtk_widget_class_bind_template_child (widget_class, ConstraintEditor, preview);
+  gtk_widget_class_bind_template_child (widget_class, ConstraintEditor, button);
+
+  gtk_widget_class_bind_template_callback (widget_class, update_preview);
+  gtk_widget_class_bind_template_callback (widget_class, update_button);
+  gtk_widget_class_bind_template_callback (widget_class, create_constraint);
+  gtk_widget_class_bind_template_callback (widget_class, source_attr_changed);
+}
+
+ConstraintEditor *
+constraint_editor_new (GListModel    *model,
+                       GtkConstraint *constraint)
+{
+  return g_object_new (CONSTRAINT_EDITOR_TYPE,
+                       "model", model,
+                       "constraint", constraint,
+                       NULL);
+}

demos/constraint-editor/constraint-editor.css

@@ -0,0 +1,12 @@
+constraintview {
+  background: black;
+  color: white;
+}
+
+constraintview .child {
+  background: red;
+}
+
+constraintview .guide {
+  background: blue;
+}

demos/constraint-editor/constraint-editor.gresource.xml

@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<gresources>
+  <gresource prefix="/org/gtk/gtk4/constraint-editor">
+    <file preprocess="xml-stripblanks">constraint-editor-window.ui</file>
+    <file preprocess="xml-stripblanks">constraint-editor.ui</file>
+    <file preprocess="xml-stripblanks">guide-editor.ui</file>
+    <file>constraint-editor.css</file>
+  </gresource>
+</gresources>

demos/constraint-editor/constraint-editor.h

@@ -0,0 +1,34 @@
+/*
+ * Copyright © 2019 Red Hat, Inc
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library. If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Authors: Matthias Clasen
+ */
+
+#pragma once
+
+#include <gtk/gtk.h>
+
+#define CONSTRAINT_EDITOR_TYPE (constraint_editor_get_type ())
+
+G_DECLARE_FINAL_TYPE (ConstraintEditor, constraint_editor, CONSTRAINT, EDITOR, GtkWidget)
+
+ConstraintEditor * constraint_editor_new (GListModel    *model,
+                                          GtkConstraint *constraint);
+
+void constraint_editor_serialize_constraint (GString       *str,
+                                             int            indent,
+                                             GtkConstraint *constraint);
+char *constraint_editor_constraint_to_string (GtkConstraint *constraint);

demos/constraint-editor/constraint-editor.ui

@@ -0,0 +1,204 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<interface>
+  <object class="GtkStringList" id="targets">
+    <items>
+      <item>None</item>
+      <item>Left</item>
+      <item>Right</item>
+      <item>Top</item>
+      <item>Bottom</item>
+      <item>Start</item>
+      <item>End</item>
+      <item>Width</item>
+      <item>Height</item>
+      <item>Center X</item>
+      <item>Center Y</item>
+      <item>Baseline</item>
+    </items>
+  </object>
+  <template class="ConstraintEditor" parent="GtkWidget">
+    <child>
+      <object class="GtkGrid" id="grid">
+        <property name="margin-start">20</property>
+        <property name="margin-end">20</property>
+        <property name="margin-top">20</property>
+        <property name="margin-bottom">20</property>
+        <property name="row-spacing">10</property>
+        <property name="column-spacing">10</property>
+        <child>
+          <object class="GtkLabel">
+            <property name="label">Target</property>
+            <layout>
+              <property name="column">0</property>
+              <property name="row">1</property>
+            </layout>
+          </object>
+        </child>
+        <child>
+          <object class="GtkDropDown" id="target">
+            <signal name="notify::selected" handler="update_preview" swapped="yes"/>
+            <signal name="notify::selected" handler="update_button" swapped="yes"/>
+            <layout>
+              <property name="column">1</property>
+              <property name="row">1</property>
+            </layout>
+          </object>
+        </child>
+        <child>
+          <object class="GtkDropDown" id="target_attr">
+            <property name="model">targets</property>
+            <signal name="notify::selected" handler="update_preview" swapped="yes"/>
+            <layout>
+              <property name="column">2</property>
+              <property name="row">1</property>
+            </layout>
+          </object>
+        </child>
+        <child>
+          <object class="GtkLabel">
+            <property name="label">Relation</property>
+            <layout>
+              <property name="column">0</property>
+              <property name="row">2</property>
+            </layout>
+          </object>
+        </child>
+        <child>
+          <object class="GtkDropDown" id="relation">
+            <signal name="notify::selected" handler="update_preview" swapped="yes"/>
+            <property name="model">
+              <object class="GtkStringList">
+                <items>
+                  <item>≤</item>
+                  <item>=</item>
+                  <item>≥</item>
+                </items>
+              </object>
+            </property>
+            <layout>
+              <property name="column">1</property>
+              <property name="row">2</property>
+            </layout>
+          </object>
+        </child>
+        <child>
+          <object class="GtkLabel">
+            <property name="label">Source</property>
+            <layout>
+              <property name="column">0</property>
+              <property name="row">3</property>
+            </layout>
+          </object>
+        </child>
+        <child>
+          <object class="GtkDropDown" id="source">
+            <signal name="notify::selected" handler="update_preview" swapped="yes"/>
+            <signal name="notify::selected" handler="update_button" swapped="yes"/>
+            <layout>
+              <property name="column">1</property>
+              <property name="row">3</property>
+            </layout>
+          </object>
+        </child>
+        <child>
+          <object class="GtkDropDown" id="source_attr">
+            <property name="model">targets</property>
+            <signal name="notify::selected" handler="update_preview" swapped="yes"/>
+            <signal name="notify::selected" handler="source_attr_changed" swapped="yes"/>
+            <signal name="notify::selected" handler="update_button" swapped="yes"/>
+            <layout>
+              <property name="column">2</property>
+              <property name="row">3</property>
+            </layout>
+          </object>
+        </child>
+        <child>
+          <object class="GtkLabel">
+            <property name="label">Multiplier</property>
+            <layout>
+              <property name="column">0</property>
+              <property name="row">4</property>
+            </layout>
+          </object>
+        </child>
+        <child>
+          <object class="GtkEntry" id="multiplier">
+            <signal name="changed" handler="update_preview" swapped="yes"/>
+            <layout>
+              <property name="column">1</property>
+              <property name="row">4</property>
+            </layout>
+          </object>
+        </child>
+        <child>
+          <object class="GtkLabel">
+            <property name="label">Constant</property>
+            <layout>
+              <property name="column">0</property>
+              <property name="row">5</property>
+            </layout>
+          </object>
+        </child>
+        <child>
+          <object class="GtkEntry" id="constant">
+            <signal name="changed" handler="update_preview" swapped="yes"/>
+            <layout>
+              <property name="column">1</property>
+              <property name="row">5</property>
+            </layout>
+          </object>
+        </child>
+        <child>
+          <object class="GtkLabel">
+            <property name="label">Strength</property>
+            <layout>
+              <property name="column">0</property>
+              <property name="row">6</property>
+            </layout>
+          </object>
+        </child>
+        <child>
+          <object class="GtkDropDown" id="strength">
+            <property name="model">
+              <object class="GtkStringList">
+                <items>
+                  <item>Weak</item>
+                  <item>Medium</item>
+                  <item>Strong</item>
+                  <item>Required</item>
+                </items>
+              </object>
+            </property>
+            <layout>
+              <property name="column">1</property>
+              <property name="row">6</property>
+            </layout>
+          </object>
+        </child>
+        <child>
+          <object class="GtkLabel" id="preview">
+            <property name="xalign">0</property>
+            <layout>
+              <property name="column">1</property>
+              <property name="row">7</property>
+              <property name="column-span">2</property>
+            </layout>
+            <attributes>
+              <attribute name="scale" value="1.44"/>
+            </attributes>
+          </object>
+        </child>
+        <child>
+          <object class="GtkButton" id="button">
+            <property name="label">Create</property>
+            <signal name="clicked" handler="create_constraint"/>
+            <layout>
+              <property name="column">2</property>
+              <property name="row">8</property>
+            </layout>
+          </object>
+        </child>
+      </object>
+    </child>
+  </template>
+</interface>

demos/constraint-editor/constraint-view-child.c

@@ -0,0 +1,93 @@
+/*
+ * Copyright © 2019 Red Hat, Inc
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library. If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Authors: Matthias Clasen
+ */
+
+#include "constraint-view-child.h"
+
+struct _ConstraintViewChild
+{
+  GObject parent_instance;
+
+  char *name;
+};
+
+enum {
+  PROP_NAME = 1,
+  LAST_PROP
+};
+
+static GParamSpec props[LAST_PROP];
+
+G_DEFINE_TYPE (ConstraintViewChild, constraint_view_child, G_TYPE_OBJECT)
+
+static void
+constraint_view_child_init (ConstraintViewChild *child)
+{
+}
+
+static void
+constraint_view_child_finalize (GObject *object)
+{
+  ConstraintViewChild *child = CONSTRAINT_VIEW_CHILD (object);
+
+  g_free (child->name);
+
+  G_OBJECT_CLASS (constraint_view_child_parent_class)->finalize (object);
+}
+
+static void
+constraint_view_child_set_property (GObject *object,
+                                    
+static void
+constraint_view_child_class_init (ConstraintViewChildClass *class)
+{
+  GObjectClass *object_class = G_OBJECT_CLASS (class);
+
+  object_class->finalize = constraint_view_child_finalize;
+  object_class->get_property = constraint_view_child_get_property;
+  object_class->set_property = constraint_view_child_set_property;
+
+  props[PROP_NAME] =
+    g_param_spec_string ("name", "name", "name",
+                         NULL,
+                         G_PARAM_READWRITE);
+
+  g_object_class_install_properties (object_class, LAST_PROP, props);
+}
+
+#define CONSTRAINT_VIEW_CHILD_TYPE (constraint_view_get_type ())
+
+G_DECLARE_TYPE (ConstraintViewChild, constraint_view_child, CONSTRAINT, VIEW_CHILD, GObject)
+
+#define CONSTRAINT_VIEW_WIDGET_TYPE (constraint_view_widget_get_type ())
+
+G_DECLARE_FINAL_TYPE (ConstraintViewWidget, constraint_view_widget, CONSTRAINT, VIEW_WIDGET, ConstraintViewChild)
+
+ConstraintViewWidget * constraint_view_widget_new (void);
+
+#define CONSTRAINT_VIEW_GUIDE_TYPE (constraint_view_guide_get_type ())
+
+G_DECLARE_FINAL_TYPE (ConstraintViewGuide, constraint_view_guide, CONSTRAINT, VIEW_GUIDE, ConstraintViewChild)
+
+ConstraintViewGuide * constraint_view_guide_new (void);
+
+#define CONSTRAINT_VIEW_CONSTRAINT_TYPE (constraint_view_constraint_get_type ())
+
+G_DECLARE_FINAL_TYPE (ConstraintViewConstraint, constraint_view_constraint, CONSTRAINT, VIEW_CONSTRAINT, ConstraintViewChild)
+
+ConstraintViewGuide * constraint_view_constraint_new (void);

demos/constraint-editor/constraint-view-child.h

@@ -0,0 +1,44 @@
+/*
+ * Copyright © 2019 Red Hat, Inc
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library. If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Authors: Matthias Clasen
+ */
+
+#pragma once
+
+#include <gtk/gtk.h>
+
+#define CONSTRAINT_VIEW_CHILD_TYPE (constraint_view_get_type ())
+
+G_DECLARE_TYPE (ConstraintViewChild, constraint_view_child, CONSTRAINT, VIEW_CHILD, GObject)
+
+#define CONSTRAINT_VIEW_WIDGET_TYPE (constraint_view_widget_get_type ())
+
+G_DECLARE_FINAL_TYPE (ConstraintViewWidget, constraint_view_widget, CONSTRAINT, VIEW_WIDGET, ConstraintViewChild)
+
+ConstraintViewWidget * constraint_view_widget_new (void);
+
+#define CONSTRAINT_VIEW_GUIDE_TYPE (constraint_view_guide_get_type ())
+
+G_DECLARE_FINAL_TYPE (ConstraintViewGuide, constraint_view_guide, CONSTRAINT, VIEW_GUIDE, ConstraintViewChild)
+
+ConstraintViewGuide * constraint_view_guide_new (void);
+
+#define CONSTRAINT_VIEW_CONSTRAINT_TYPE (constraint_view_constraint_get_type ())
+
+G_DECLARE_FINAL_TYPE (ConstraintViewConstraint, constraint_view_constraint, CONSTRAINT, VIEW_CONSTRAINT, ConstraintViewChild)
+
+ConstraintViewGuide * constraint_view_constraint_new (void);

demos/constraint-editor/constraint-view.c

@@ -0,0 +1,345 @@
+/* Copyright (C) 2019 Red Hat, Inc.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <gtk/gtk.h>
+#include "constraint-view.h"
+
+struct _ConstraintView
+{
+  GtkWidget parent;
+
+  GListModel *model;
+
+  GtkWidget *drag_widget;
+};
+
+G_DEFINE_TYPE (ConstraintView, constraint_view, GTK_TYPE_WIDGET);
+
+static void
+constraint_view_dispose (GObject *object)
+{
+  ConstraintView *view = CONSTRAINT_VIEW (object);
+  GtkWidget *child;
+
+  while ((child = gtk_widget_get_first_child (GTK_WIDGET (view))) != NULL)
+    gtk_widget_unparent (child);
+
+  g_clear_object (&view->model);
+
+  G_OBJECT_CLASS (constraint_view_parent_class)->dispose (object);
+}
+
+static void
+constraint_view_class_init (ConstraintViewClass *klass)
+{
+  GObjectClass *object_class = G_OBJECT_CLASS (klass);
+  GtkWidgetClass *widget_class = GTK_WIDGET_CLASS (klass);
+
+  object_class->dispose = constraint_view_dispose;
+
+  gtk_widget_class_set_css_name (widget_class, "constraintview");
+}
+
+static void
+update_weak_position (ConstraintView *self,
+                      GtkWidget      *child,
+                      double          x,
+                      double          y)
+{
+  GtkLayoutManager *manager;
+  GtkConstraint *constraint;
+
+  manager = gtk_widget_get_layout_manager (GTK_WIDGET (self));
+  constraint = (GtkConstraint *)g_object_get_data (G_OBJECT (child), "x-constraint");
+  if (constraint)
+    {
+      gtk_constraint_layout_remove_constraint (GTK_CONSTRAINT_LAYOUT (manager),
+                                               constraint);
+      g_object_set_data (G_OBJECT (child), "x-constraint", NULL);
+    }
+  if (x != -100)
+    {
+      constraint = gtk_constraint_new_constant (child,
+                                                GTK_CONSTRAINT_ATTRIBUTE_CENTER_X,
+                                                GTK_CONSTRAINT_RELATION_EQ,
+                                                x,
+                                                GTK_CONSTRAINT_STRENGTH_WEAK);
+      g_object_set_data (G_OBJECT (constraint), "internal", (char *)"yes");
+      gtk_constraint_layout_add_constraint (GTK_CONSTRAINT_LAYOUT (manager),
+                                            constraint);
+      g_object_set_data (G_OBJECT (child), "x-constraint", constraint);
+    }
+
+  constraint = (GtkConstraint *)g_object_get_data (G_OBJECT (child), "y-constraint");
+  if (constraint)
+    {
+      gtk_constraint_layout_remove_constraint (GTK_CONSTRAINT_LAYOUT (manager),
+                                                   constraint);
+      g_object_set_data (G_OBJECT (child), "y-constraint", NULL);
+    }
+  if (y != -100)
+    {
+      constraint = gtk_constraint_new_constant (child,
+                                                GTK_CONSTRAINT_ATTRIBUTE_CENTER_Y,
+                                                GTK_CONSTRAINT_RELATION_EQ,
+                                                y,
+                                                GTK_CONSTRAINT_STRENGTH_WEAK);
+      g_object_set_data (G_OBJECT (constraint), "internal", (char *)"yes");
+      gtk_constraint_layout_add_constraint (GTK_CONSTRAINT_LAYOUT (manager),
+                                            constraint);
+      g_object_set_data (G_OBJECT (child), "y-constraint", constraint);
+    }
+}
+
+static void
+drag_begin (GtkGestureDrag *drag,
+            double          start_x,
+            double          start_y,
+            ConstraintView *self)
+{
+  GtkWidget *widget;
+
+  widget = gtk_widget_pick (GTK_WIDGET (self), start_x, start_y, GTK_PICK_DEFAULT);
+
+  if (GTK_IS_LABEL (widget))
+    {
+      widget = gtk_widget_get_ancestor (widget, GTK_TYPE_FRAME);
+      if (widget &&
+          gtk_widget_get_parent (widget) == (GtkWidget *)self)
+        {
+          self->drag_widget = widget;
+        }
+    }
+}
+
+static void
+drag_update (GtkGestureDrag *drag,
+             double          offset_x,
+             double          offset_y,
+             ConstraintView *self)
+{
+  double x, y;
+
+  if (!self->drag_widget)
+    return;
+
+  gtk_gesture_drag_get_start_point (drag, &x, &y);
+  update_weak_position (self, self->drag_widget, x + offset_x, y + offset_y);
+}
+
+static void
+drag_end (GtkGestureDrag *drag,
+          double          offset_x,
+          double          offset_y,
+          ConstraintView *self)
+{
+  self->drag_widget = NULL;
+}
+
+static gboolean
+omit_internal (gpointer item, gpointer user_data)
+{
+  if (g_object_get_data (G_OBJECT (item), "internal"))
+    return FALSE;
+
+  return TRUE;
+}
+
+static void
+constraint_view_init (ConstraintView *self)
+{
+  GtkLayoutManager *manager;
+  GtkEventController *controller;
+  GListStore *list;
+  GListModel *all_children;
+  GListModel *all_constraints;
+  GListModel *guides;
+  GListModel *children;
+  GListModel *constraints;
+  GtkFilter *filter;
+
+  manager = gtk_constraint_layout_new ();
+  gtk_widget_set_layout_manager (GTK_WIDGET (self), manager);
+
+  guides = gtk_constraint_layout_observe_guides (GTK_CONSTRAINT_LAYOUT (manager));
+
+  all_constraints = gtk_constraint_layout_observe_constraints (GTK_CONSTRAINT_LAYOUT (manager));
+  filter = GTK_FILTER (gtk_custom_filter_new (omit_internal, NULL, NULL));
+  constraints = (GListModel *)gtk_filter_list_model_new (all_constraints, filter);
+
+  all_children = gtk_widget_observe_children (GTK_WIDGET (self));
+  filter = GTK_FILTER (gtk_custom_filter_new (omit_internal, NULL, NULL));
+  children = (GListModel *)gtk_filter_list_model_new (all_children, filter);
+
+  list = g_list_store_new (G_TYPE_LIST_MODEL);
+  g_list_store_append (list, children);
+  g_list_store_append (list, guides);
+  g_list_store_append (list, constraints);
+  g_object_unref (children);
+  g_object_unref (guides);
+  g_object_unref (constraints);
+
+  self->model = G_LIST_MODEL (gtk_flatten_list_model_new (G_LIST_MODEL (list)));
+
+  controller = (GtkEventController *)gtk_gesture_drag_new ();
+  g_signal_connect (controller, "drag-begin", G_CALLBACK (drag_begin), self);
+  g_signal_connect (controller, "drag-update", G_CALLBACK (drag_update), self);
+  g_signal_connect (controller, "drag-end", G_CALLBACK (drag_end), self);
+  gtk_widget_add_controller (GTK_WIDGET (self), controller);
+}
+
+ConstraintView *
+constraint_view_new (void)
+{
+  return g_object_new (CONSTRAINT_VIEW_TYPE, NULL);
+}
+
+void
+constraint_view_add_child (ConstraintView *view,
+                           const char     *name)
+{
+  GtkWidget *frame;
+  GtkWidget *label;
+
+  label = gtk_label_new (name);
+  frame = gtk_frame_new (NULL);
+  gtk_widget_add_css_class (frame, "child");
+  gtk_widget_set_name (frame, name);
+  gtk_frame_set_child (GTK_FRAME (frame), label);
+  gtk_widget_set_parent (frame, GTK_WIDGET (view));
+
+  update_weak_position (view, frame, 100, 100);
+}
+
+void
+constraint_view_remove_child (ConstraintView *view,
+                              GtkWidget      *child)
+{
+  update_weak_position (view, child, -100, -100);
+  gtk_widget_unparent (child);
+}
+
+void
+constraint_view_add_guide (ConstraintView *view,
+                           GtkConstraintGuide *guide)
+{
+  GtkConstraintLayout *layout;
+  GtkWidget *frame;
+  GtkWidget *label;
+  const char *name;
+  GtkConstraint *constraint;
+  struct {
+    const char *name;
+    GtkConstraintAttribute attr;
+  } names[] = {
+    { "left-constraint", GTK_CONSTRAINT_ATTRIBUTE_LEFT },
+    { "top-constraint", GTK_CONSTRAINT_ATTRIBUTE_TOP },
+    { "width-constraint", GTK_CONSTRAINT_ATTRIBUTE_WIDTH },
+    { "height-constraint", GTK_CONSTRAINT_ATTRIBUTE_HEIGHT },
+  };
+  int i;
+
+  name = gtk_constraint_guide_get_name (guide);
+  label = gtk_label_new (name);
+  g_object_bind_property (guide, "name",
+                          label, "label",
+                          G_BINDING_DEFAULT);
+
+  frame = gtk_frame_new (NULL);
+  gtk_widget_add_css_class (frame, "guide");
+  g_object_set_data (G_OBJECT (frame), "internal", (char *)"yes");
+  gtk_frame_set_child (GTK_FRAME (frame), label);
+  gtk_widget_insert_after (frame, GTK_WIDGET (view), NULL);
+
+  g_object_set_data (G_OBJECT (guide), "frame", frame);
+
+  layout = GTK_CONSTRAINT_LAYOUT (gtk_widget_get_layout_manager (GTK_WIDGET (view)));
+  gtk_constraint_layout_add_guide (layout, g_object_ref (guide));
+
+  for (i = 0; i < G_N_ELEMENTS (names); i++)
+    {
+      constraint = gtk_constraint_new (frame,
+                                       names[i].attr,
+                                       GTK_CONSTRAINT_RELATION_EQ,
+                                       guide,
+                                       names[i].attr,
+                                       1.0, 0.0,
+                                       GTK_CONSTRAINT_STRENGTH_REQUIRED);
+      g_object_set_data (G_OBJECT (constraint), "internal", (char *)"yes");
+      gtk_constraint_layout_add_constraint (layout, constraint);
+      g_object_set_data (G_OBJECT (guide), names[i].name, constraint);
+    }
+
+  update_weak_position (view, frame, 150, 150);
+}
+
+void
+constraint_view_remove_guide (ConstraintView     *view,
+                              GtkConstraintGuide *guide)
+{
+  GtkConstraintLayout *layout;
+  GtkWidget *frame;
+  GtkConstraint *constraint;
+  const char *names[] = {
+    "left-constraint",
+    "top-constraint",
+    "width-constraint",
+    "height-constraint"
+  };
+  int i;
+
+  layout = GTK_CONSTRAINT_LAYOUT (gtk_widget_get_layout_manager (GTK_WIDGET (view)));
+
+  for (i = 0; i < G_N_ELEMENTS (names); i++)
+    {
+      constraint = (GtkConstraint*)g_object_get_data (G_OBJECT (guide), names[i]);
+      gtk_constraint_layout_remove_constraint (layout, constraint);
+    }
+
+  frame = (GtkWidget *)g_object_get_data (G_OBJECT (guide), "frame");
+  update_weak_position (view, frame, -100, -100);
+  gtk_widget_unparent (frame);
+
+  gtk_constraint_layout_remove_guide (layout, guide);
+}
+
+void
+constraint_view_add_constraint (ConstraintView *view,
+                                GtkConstraint  *constraint)
+{
+  GtkLayoutManager *manager;
+
+  manager = gtk_widget_get_layout_manager (GTK_WIDGET (view));
+  gtk_constraint_layout_add_constraint (GTK_CONSTRAINT_LAYOUT (manager),
+                                        g_object_ref (constraint));
+}
+
+void
+constraint_view_remove_constraint (ConstraintView *view,
+                                   GtkConstraint  *constraint)
+{
+  GtkLayoutManager *manager;
+
+  manager = gtk_widget_get_layout_manager (GTK_WIDGET (view));
+  gtk_constraint_layout_remove_constraint (GTK_CONSTRAINT_LAYOUT (manager),
+                                           constraint);
+}
+
+GListModel *
+constraint_view_get_model (ConstraintView *view)
+{
+  return view->model;
+}

demos/constraint-editor/constraint-view.h

@@ -0,0 +1,45 @@
+/*
+ * Copyright © 2019 Red Hat, Inc
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library. If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Authors: Matthias Clasen
+ */
+
+#pragma once
+
+#include <gtk/gtk.h>
+
+#define CONSTRAINT_VIEW_TYPE (constraint_view_get_type ())
+
+G_MODULE_EXPORT
+G_DECLARE_FINAL_TYPE (ConstraintView, constraint_view, CONSTRAINT, VIEW, GtkWidget)
+
+ConstraintView * constraint_view_new (void);
+
+void             constraint_view_add_child (ConstraintView *view,
+                                            const char     *name);
+void             constraint_view_remove_child (ConstraintView *view,
+                                               GtkWidget      *child);
+void             constraint_view_add_guide (ConstraintView     *view,
+                                            GtkConstraintGuide *guide);
+void             constraint_view_remove_guide (ConstraintView     *view,
+                                               GtkConstraintGuide *guide);
+void             constraint_view_guide_changed (ConstraintView     *view,
+                                                GtkConstraintGuide *guide);
+void             constraint_view_add_constraint (ConstraintView *view,
+                                                 GtkConstraint  *constraint);
+void             constraint_view_remove_constraint (ConstraintView *view,
+                                                    GtkConstraint  *constraint);
+GListModel *     constraint_view_get_model (ConstraintView *view);

demos/constraint-editor/guide-editor.c

@@ -0,0 +1,355 @@
+/*
+ * Copyright © 2019 Red Hat, Inc.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library. If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Authors: Matthias Clasen
+ */
+
+#include "config.h"
+
+#include "guide-editor.h"
+
+struct _GuideEditor
+{
+  GtkWidget parent_instance;
+
+  GtkWidget *grid;
+  GtkWidget *name;
+  GtkWidget *min_width;
+  GtkWidget *min_height;
+  GtkWidget *nat_width;
+  GtkWidget *nat_height;
+  GtkWidget *max_width;
+  GtkWidget *max_height;
+  GtkWidget *strength;
+  GtkWidget *button;
+
+  GtkConstraintGuide *guide;
+
+  gboolean constructed;
+};
+
+enum {
+  PROP_GUIDE = 1,
+  LAST_PROP
+};
+
+static GParamSpec *pspecs[LAST_PROP];
+
+enum {
+  DONE,
+  LAST_SIGNAL
+};
+
+static guint signals[LAST_SIGNAL];
+
+G_DEFINE_TYPE(GuideEditor, guide_editor, GTK_TYPE_WIDGET);
+
+static GtkConstraintStrength
+get_strength (unsigned int id)
+{
+  switch (id)
+    {
+    case 0: return GTK_CONSTRAINT_STRENGTH_WEAK;
+    case 1: return GTK_CONSTRAINT_STRENGTH_MEDIUM;
+    case 2: return GTK_CONSTRAINT_STRENGTH_STRONG;
+    case 3: return GTK_CONSTRAINT_STRENGTH_REQUIRED;
+    default: g_assert_not_reached ();
+    }
+}
+
+static unsigned int
+get_strength_id (GtkConstraintStrength strength)
+{
+  switch (strength)
+    {
+    case GTK_CONSTRAINT_STRENGTH_WEAK: return 0;
+    case GTK_CONSTRAINT_STRENGTH_MEDIUM: return 1;
+    case GTK_CONSTRAINT_STRENGTH_STRONG: return 2;
+    case GTK_CONSTRAINT_STRENGTH_REQUIRED: return 3;
+    default: g_assert_not_reached ();
+    }
+}
+
+static const char *
+get_strength_nick (GtkConstraintStrength strength)
+{
+  GEnumClass *class = g_type_class_ref (GTK_TYPE_CONSTRAINT_STRENGTH);
+  GEnumValue *value = g_enum_get_value (class, strength);
+  const char *nick = value->value_nick;
+  g_type_class_unref (class);
+
+  return nick;
+}
+
+void
+guide_editor_serialize_guide (GString *str,
+                              int      indent,
+                              GtkConstraintGuide *guide)
+{
+  int min_width, min_height;
+  int nat_width, nat_height;
+  int max_width, max_height;
+  const char *name;
+  const char *strength;
+
+  gtk_constraint_guide_get_min_size (guide, &min_width, &min_height);
+  gtk_constraint_guide_get_nat_size (guide, &nat_width, &nat_height);
+  gtk_constraint_guide_get_max_size (guide, &max_width, &max_height);
+  name = gtk_constraint_guide_get_name (guide);
+  strength = get_strength_nick (gtk_constraint_guide_get_strength (guide));
+
+  g_string_append_printf (str, "%*s<guide min-width=\"%d\" min-height=\"%d\"\n", indent, "", min_width, min_height);
+  g_string_append_printf (str, "%*s       nat-width=\"%d\" nat-height=\"%d\"\n", indent, "", nat_width, nat_height);
+  g_string_append_printf (str, "%*s       max-width=\"%d\" max-height=\"%d\"\n", indent, "", max_width, max_height);
+  g_string_append_printf (str, "%*s       name=\"%s\" strength=\"%s\" />\n", indent, "", name, strength);
+}
+
+static void
+create_guide (GtkButton   *button,
+              GuideEditor *editor)
+{
+  int strength;
+  const char *name;
+  int w, h;
+  GtkConstraintGuide *guide;
+  unsigned int id;
+
+  if (editor->guide)
+    guide = g_object_ref (editor->guide);
+  else
+    guide = gtk_constraint_guide_new ();
+
+  name = gtk_editable_get_text (GTK_EDITABLE (editor->name));
+  gtk_constraint_guide_set_name (guide, name);
+
+  w = gtk_spin_button_get_value_as_int (GTK_SPIN_BUTTON (editor->min_width));
+  h = gtk_spin_button_get_value_as_int (GTK_SPIN_BUTTON (editor->min_height));
+  gtk_constraint_guide_set_min_size (guide, w, h);
+
+  w = gtk_spin_button_get_value_as_int (GTK_SPIN_BUTTON (editor->nat_width));
+  h = gtk_spin_button_get_value_as_int (GTK_SPIN_BUTTON (editor->nat_height));
+  gtk_constraint_guide_set_nat_size (guide, w, h);
+
+  w = gtk_spin_button_get_value_as_int (GTK_SPIN_BUTTON (editor->max_width));
+  h = gtk_spin_button_get_value_as_int (GTK_SPIN_BUTTON (editor->max_height));
+  gtk_constraint_guide_set_max_size (guide, w, h);
+
+  id = gtk_drop_down_get_selected (GTK_DROP_DOWN (editor->strength));
+  strength = get_strength (id);
+  gtk_constraint_guide_set_strength (guide, strength);
+
+  g_signal_emit (editor, signals[DONE], 0, guide);
+  g_object_unref (guide);
+}
+
+static void
+guide_editor_init (GuideEditor *editor)
+{
+  gtk_widget_init_template (GTK_WIDGET (editor));
+}
+
+static int guide_counter;
+
+static int
+min_input (GtkSpinButton *spin_button,
+           double        *new_val)
+{
+  if (strcmp (gtk_editable_get_text (GTK_EDITABLE (spin_button)), "") == 0)
+    {
+      *new_val = 0.0;
+      return TRUE;
+    }
+
+  return FALSE;
+}
+
+static int
+max_input (GtkSpinButton *spin_button,
+           double        *new_val)
+{
+  if (strcmp (gtk_editable_get_text (GTK_EDITABLE (spin_button)), "") == 0)
+    {
+      *new_val = G_MAXINT;
+      return TRUE;
+    }
+
+  return FALSE;
+}
+
+static void
+guide_editor_constructed (GObject *object)
+{
+  GuideEditor *editor = GUIDE_EDITOR (object);
+
+  g_signal_connect (editor->min_width, "input", G_CALLBACK (min_input), NULL);
+  g_signal_connect (editor->min_height, "input", G_CALLBACK (min_input), NULL);
+  g_signal_connect (editor->max_width, "input", G_CALLBACK (max_input), NULL);
+  g_signal_connect (editor->max_height, "input", G_CALLBACK (max_input), NULL);
+
+  if (editor->guide)
+    {
+      GtkConstraintStrength strength;
+      const char *nick;
+      int w, h;
+
+      nick = gtk_constraint_guide_get_name (editor->guide);
+      if (nick)
+        gtk_editable_set_text (GTK_EDITABLE (editor->name), nick);
+
+      gtk_constraint_guide_get_min_size (editor->guide, &w, &h);
+      gtk_spin_button_set_value (GTK_SPIN_BUTTON (editor->min_width), w);
+      gtk_spin_button_set_value (GTK_SPIN_BUTTON (editor->min_height), h);
+
+      gtk_constraint_guide_get_nat_size (editor->guide, &w, &h);
+      gtk_spin_button_set_value (GTK_SPIN_BUTTON (editor->nat_width), w);
+      gtk_spin_button_set_value (GTK_SPIN_BUTTON (editor->nat_height), h);
+
+      gtk_constraint_guide_get_max_size (editor->guide, &w, &h);
+      gtk_spin_button_set_value (GTK_SPIN_BUTTON (editor->max_width), w);
+      gtk_spin_button_set_value (GTK_SPIN_BUTTON (editor->max_height), h);
+
+      strength = gtk_constraint_guide_get_strength (editor->guide);
+      gtk_drop_down_set_selected (GTK_DROP_DOWN (editor->strength), get_strength_id (strength));
+
+      gtk_button_set_label (GTK_BUTTON (editor->button), "Apply");
+    }
+  else
+    {
+      char *name;
+
+      guide_counter++;
+      name = g_strdup_printf ("Guide %d", guide_counter);
+      gtk_editable_set_text (GTK_EDITABLE (editor->name), name);
+      g_free (name);
+
+      gtk_spin_button_set_value (GTK_SPIN_BUTTON (editor->min_width), 0.0);
+      gtk_spin_button_set_value (GTK_SPIN_BUTTON (editor->min_height), 0.0);
+      gtk_spin_button_set_value (GTK_SPIN_BUTTON (editor->nat_width), 0.0);
+      gtk_spin_button_set_value (GTK_SPIN_BUTTON (editor->nat_height), 0.0);
+      gtk_spin_button_set_value (GTK_SPIN_BUTTON (editor->max_width), G_MAXINT);
+      gtk_spin_button_set_value (GTK_SPIN_BUTTON (editor->max_height), G_MAXINT);
+
+      gtk_drop_down_set_selected (GTK_DROP_DOWN (editor->strength), get_strength_id (GTK_CONSTRAINT_STRENGTH_MEDIUM));
+
+      gtk_button_set_label (GTK_BUTTON (editor->button), "Create");
+    }
+
+  editor->constructed = TRUE;
+}
+
+static void
+guide_editor_set_property (GObject      *object,
+                           guint         property_id,
+                           const GValue *value,
+                           GParamSpec   *pspec)
+{
+  GuideEditor *self = GUIDE_EDITOR (object);
+
+  switch (property_id)
+    {
+    case PROP_GUIDE:
+      self->guide = g_value_dup_object (value);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+    }
+}
+
+static void
+guide_editor_get_property (GObject    *object,
+                           guint       property_id,
+                           GValue     *value,
+                           GParamSpec *pspec)
+{
+  GuideEditor *self = GUIDE_EDITOR (object);
+
+  switch (property_id)
+    {
+    case PROP_GUIDE:
+      g_value_set_object (value, self->guide);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+    }
+}
+
+static void
+guide_editor_dispose (GObject *object)
+{
+  GuideEditor *self = (GuideEditor *)object;
+
+  g_clear_object (&self->guide);
+
+  gtk_widget_dispose_template (GTK_WIDGET (self), GUIDE_EDITOR_TYPE);
+
+  G_OBJECT_CLASS (guide_editor_parent_class)->dispose (object);
+}
+
+static void
+guide_editor_class_init (GuideEditorClass *class)
+{
+  GObjectClass *object_class = G_OBJECT_CLASS (class);
+  GtkWidgetClass *widget_class = GTK_WIDGET_CLASS (class);
+
+  object_class->constructed = guide_editor_constructed;
+  object_class->dispose = guide_editor_dispose;
+  object_class->set_property = guide_editor_set_property;
+  object_class->get_property = guide_editor_get_property;
+
+  pspecs[PROP_GUIDE] =
+    g_param_spec_object ("guide", "guide", "guide",
+                         GTK_TYPE_CONSTRAINT_GUIDE,
+                         G_PARAM_READWRITE|G_PARAM_CONSTRUCT_ONLY);
+
+  g_object_class_install_properties (object_class, LAST_PROP, pspecs);
+
+  signals[DONE] =
+    g_signal_new ("done",
+                  G_TYPE_FROM_CLASS (object_class),
+                  G_SIGNAL_RUN_LAST,
+                  0,
+                  NULL, NULL,
+                  NULL,
+                  G_TYPE_NONE, 1, GTK_TYPE_CONSTRAINT_GUIDE);
+
+  gtk_widget_class_set_layout_manager_type (widget_class, GTK_TYPE_BIN_LAYOUT);
+
+  gtk_widget_class_set_template_from_resource (widget_class,
+                                               "/org/gtk/gtk4/constraint-editor/guide-editor.ui");
+
+  gtk_widget_class_bind_template_child (widget_class, GuideEditor, grid);
+  gtk_widget_class_bind_template_child (widget_class, GuideEditor, name);
+  gtk_widget_class_bind_template_child (widget_class, GuideEditor, min_width);
+  gtk_widget_class_bind_template_child (widget_class, GuideEditor, min_height);
+  gtk_widget_class_bind_template_child (widget_class, GuideEditor, nat_width);
+  gtk_widget_class_bind_template_child (widget_class, GuideEditor, nat_height);
+  gtk_widget_class_bind_template_child (widget_class, GuideEditor, max_width);
+  gtk_widget_class_bind_template_child (widget_class, GuideEditor, max_height);
+  gtk_widget_class_bind_template_child (widget_class, GuideEditor, strength);
+  gtk_widget_class_bind_template_child (widget_class, GuideEditor, button);
+
+  gtk_widget_class_bind_template_callback (widget_class, create_guide);
+}
+
+GuideEditor *
+guide_editor_new (GtkConstraintGuide *guide)
+{
+  return g_object_new (GUIDE_EDITOR_TYPE,
+                       "guide", guide,
+                       NULL);
+}

demos/constraint-editor/guide-editor.h

@@ -1,11 +1,10 @@
-/* GTK - The GIMP Toolkit
- *
- * Copyright (C) 2024 the GTK team
+/*
+ * Copyright © 2019 Red Hat, Inc
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
- * version 2 of the License, or (at your option) any later version.
+ * version 2.1 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ -14,24 +13,20 @@
  *
  * You should have received a copy of the GNU Lesser General Public
  * License along with this library. If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Authors: Matthias Clasen
  */
 
 #pragma once
 
-#include <stdbool.h>
+#include <gtk/gtk.h>
 
-typedef enum {
-  OSVersionWindows7,
-  OSVersionWindows8,
-  OSVersionWindows8_1,
-  OSVersionWindows10,
-  OSVersionWindows11,
-} OSVersion;
+#define GUIDE_EDITOR_TYPE (guide_editor_get_type ())
 
-bool                  gdk_win32_check_app_container (void);
+G_DECLARE_FINAL_TYPE (GuideEditor, guide_editor, GUIDE, EDITOR, GtkWidget)
 
-bool                  gdk_win32_check_high_integrity (void);
+GuideEditor * guide_editor_new (GtkConstraintGuide  *guide);
 
-bool                  gdk_win32_check_manually_elevated (void);
-
-OSVersion             gdk_win32_get_os_version (void);
+void guide_editor_serialize_guide (GString            *str,
+                                   int                 indent,
+                                   GtkConstraintGuide *guide);

demos/constraint-editor/guide-editor.ui

@@ -0,0 +1,201 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<interface>
+  <object class="GtkAdjustment" id="min_width_adj">
+    <property name="lower">0</property>
+    <property name="upper">2147483647</property>
+    <property name="step-increment">1</property>
+    <property name="page-increment">10</property>
+    <property name="page-size">0</property>
+  </object>
+  <object class="GtkAdjustment" id="min_height_adj">
+    <property name="lower">0</property>
+    <property name="upper">2147483647</property>
+    <property name="step-increment">1</property>
+    <property name="page-increment">10</property>
+    <property name="page-size">0</property>
+  </object>
+  <object class="GtkAdjustment" id="nat_width_adj">
+    <property name="lower">0</property>
+    <property name="upper">2147483647</property>
+    <property name="step-increment">1</property>
+    <property name="page-increment">10</property>
+    <property name="page-size">0</property>
+  </object>
+  <object class="GtkAdjustment" id="nat_height_adj">
+    <property name="lower">0</property>
+    <property name="upper">2147483647</property>
+    <property name="step-increment">1</property>
+    <property name="page-increment">10</property>
+    <property name="page-size">0</property>
+  </object>
+  <object class="GtkAdjustment" id="max_width_adj">
+    <property name="lower">0</property>
+    <property name="upper">2147483647</property>
+    <property name="step-increment">1</property>
+    <property name="page-increment">10</property>
+    <property name="page-size">0</property>
+  </object>
+  <object class="GtkAdjustment" id="max_height_adj">
+    <property name="lower">0</property>
+    <property name="upper">2147483647</property>
+    <property name="step-increment">1</property>
+    <property name="page-increment">10</property>
+    <property name="page-size">0</property>
+  </object>
+  <template class="GuideEditor" parent="GtkWidget">
+    <child>
+      <object class="GtkGrid" id="grid">
+        <property name="margin-start">20</property>
+        <property name="margin-end">20</property>
+        <property name="margin-top">20</property>
+        <property name="margin-bottom">20</property>
+        <property name="row-spacing">10</property>
+        <property name="column-spacing">10</property>
+        <child>
+          <object class="GtkLabel">
+            <property name="label">Name</property>
+            <layout>
+              <property name="column">0</property>
+              <property name="row">0</property>
+            </layout>
+          </object>
+        </child>
+        <child>
+          <object class="GtkEntry" id="name">
+            <property name="max-width-chars">20</property>
+            <layout>
+              <property name="column">1</property>
+              <property name="row">0</property>
+              <property name="column-span">2</property>
+            </layout>
+          </object>
+        </child>
+        <child>
+          <object class="GtkLabel">
+            <property name="label">Min Size</property>
+            <layout>
+              <property name="column">0</property>
+              <property name="row">1</property>
+            </layout>
+          </object>
+        </child>
+        <child>
+          <object class="GtkSpinButton" id="min_width">
+            <property name="adjustment">min_width_adj</property>
+            <property name="max-width-chars">5</property>
+            <layout>
+              <property name="column">1</property>
+              <property name="row">1</property>
+            </layout>
+          </object>
+        </child>
+        <child>
+          <object class="GtkSpinButton" id="min_height">
+            <property name="adjustment">min_height_adj</property>
+            <property name="max-width-chars">5</property>
+            <layout>
+              <property name="column">2</property>
+              <property name="row">1</property>
+            </layout>
+          </object>
+        </child>
+        <child>
+          <object class="GtkLabel">
+            <property name="label">Nat Size</property>
+            <layout>
+              <property name="column">0</property>
+              <property name="row">2</property>
+            </layout>
+          </object>
+        </child>
+        <child>
+          <object class="GtkSpinButton" id="nat_width">
+            <property name="adjustment">nat_width_adj</property>
+            <property name="max-width-chars">5</property>
+            <layout>
+              <property name="column">1</property>
+              <property name="row">2</property>
+            </layout>
+          </object>
+        </child>
+        <child>
+          <object class="GtkSpinButton" id="nat_height">
+            <property name="adjustment">nat_height_adj</property>
+            <property name="max-width-chars">5</property>
+            <layout>
+              <property name="column">2</property>
+              <property name="row">2</property>
+            </layout>
+          </object>
+        </child>
+        <child>
+          <object class="GtkLabel">
+            <property name="label">Max Size</property>
+            <layout>
+              <property name="column">0</property>
+              <property name="row">3</property>
+            </layout>
+          </object>
+        </child>
+        <child>
+          <object class="GtkSpinButton" id="max_width">
+            <property name="adjustment">max_width_adj</property>
+            <property name="max-width-chars">5</property>
+            <layout>
+              <property name="column">1</property>
+              <property name="row">3</property>
+            </layout>
+          </object>
+        </child>
+        <child>
+          <object class="GtkSpinButton" id="max_height">
+            <property name="adjustment">max_height_adj</property>
+            <property name="max-width-chars">5</property>
+            <layout>
+              <property name="column">2</property>
+              <property name="row">3</property>
+            </layout>
+          </object>
+        </child>
+        <child>
+          <object class="GtkLabel">
+            <property name="label">Strength</property>
+            <layout>
+              <property name="column">0</property>
+              <property name="row">4</property>
+            </layout>
+          </object>
+        </child>
+        <child>
+          <object class="GtkDropDown" id="strength">
+            <property name="model">
+              <object class="GtkStringList">
+                <items>
+                  <item>Weak</item>
+                  <item>Medium</item>
+                  <item>Strong</item>
+                  <item>Required</item>
+                </items>
+              </object>
+            </property>
+            <layout>
+              <property name="column">1</property>
+              <property name="row">4</property>
+              <property name="column-span">2</property>
+            </layout>
+          </object>
+        </child>
+        <child>
+          <object class="GtkButton" id="button">
+            <property name="label">Create</property>
+            <signal name="clicked" handler="create_guide"/>
+            <layout>
+              <property name="column">2</property>
+              <property name="row">5</property>
+            </layout>
+          </object>
+        </child>
+      </object>
+    </child>
+  </template>
+</interface>

demos/constraint-editor/main.c

@@ -1,10 +1,10 @@
-/* GTK - The GIMP Toolkit
- * Copyright (C) 2024 the GTK team
+/*
+ * Copyright © 2019 Red Hat, Inc.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
- * version 2 of the License, or (at your option) any later version.
+ * version 2.1 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ -13,24 +13,16 @@
  *
  * You should have received a copy of the GNU Lesser General Public
  * License along with this library. If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Authors: Matthias Clasen <mclasen@redhat.com>
  */
 
-#pragma once
+#include "config.h"
 
+#include <constraint-editor-application.h>
 
-#if !defined (__GTK_H_INSIDE__) && !defined (GTK_COMPILATION)
-#error "Only <gtk/gtk.h> can be included directly."
-#endif
-
-#include <gtk/gtkcolorpickerprivate.h>
-
-G_BEGIN_DECLS
-
-
-#define GTK_TYPE_COLOR_PICKER_QUARTZ gtk_color_picker_quartz_get_type ()
-G_DECLARE_FINAL_TYPE (GtkColorPickerQuartz, gtk_color_picker_quartz, GTK, COLOR_PICKER_QUARTZ, GObject)
-
-GDK_AVAILABLE_IN_ALL
-GtkColorPicker * gtk_color_picker_quartz_new (void);
-
-G_END_DECLS
+int
+main (int argc, char *argv[])
+{
+  return g_application_run (G_APPLICATION (constraint_editor_application_new ()), argc, argv);
+}

demos/constraint-editor/meson.build

@@ -0,0 +1,23 @@
+constraint_editor_sources = [
+  'main.c',
+  'constraint-editor-application.c',
+  'constraint-editor-window.c',
+  'constraint-view.c',
+  'constraint-editor.c',
+  'guide-editor.c',
+]
+
+constraint_editor_resources = gnome.compile_resources('constraint_editor_resources',
+  'constraint-editor.gresource.xml',
+  source_dir: meson.current_source_dir(),
+)
+
+executable('gtk4-constraint-editor',
+  sources: [ constraint_editor_sources, constraint_editor_resources, ],
+  c_args: common_cflags,
+  dependencies: libgtk_dep,
+  include_directories: confinc,
+  win_subsystem: 'windows',
+  link_args: extra_demo_ldflags,
+  install: false,
+)

demos/gtk-demo/background.glsl

@@ -0,0 +1,26 @@
+uniform float u_time;
+
+void
+mainImage(out vec4 fragColor, in vec2 fragCoord, in vec2 resolution, in vec2 uv)
+{
+  vec2 pos = (fragCoord.xy * 2.0 - resolution.xy)/ min (resolution.x, resolution.y) ;
+
+  float t0 = sin ((u_time + 0.00)*1.0);
+  float t1 = sin ((u_time + 0.30)*0.4);
+  float t2 = cos ((u_time + 0.23)*0.9);
+  float t3 = cos ((u_time + 0.41)*0.6);
+  float t4 = cos ((u_time + 0.11)*0.3);
+
+  vec2 p0 = vec2 (t1, t0) ;
+  vec2 p1 = vec2 (t2, t3) ;
+  vec2 p2 = vec2 (t4, t3) ;
+
+  float r = 1.0/distance (pos, p0);
+  float g = 1.0/distance (pos, p1);
+  float b = 1.0/distance (pos, p2);
+  float sum = r + g + b;
+
+  float alpha = 1.0 - pow (1.0/(sum), 40.0)*pow (10.0, 40.0*0.7);
+
+  fragColor = vec4 (r*0.5, g*0.5, b*0.5, 1.0) * alpha;
+}

demos/gtk-demo/cogs2.glsl

@@ -0,0 +1,226 @@
+uniform float iTime;
+
+// Originally from: https://www.shadertoy.com/view/3ljyDD
+// License CC0: Hexagonal tiling + cog wheels
+//  Nothing fancy, just hexagonal tiling + cog wheels
+
+#define PI      3.141592654
+#define TAU     (2.0*PI)
+#define MROT(a) mat2(cos(a), sin(a), -sin(a), cos(a))
+
+float hash(in vec2 co) {
+  return fract(sin(dot(co.xy ,vec2(12.9898,58.233))) * 13758.5453);
+}
+
+float pcos(float a) {
+  return 0.5 + 0.5*cos(a);
+}
+
+void rot(inout vec2 p, float a) {
+  float c = cos(a);
+  float s = sin(a);
+  p = vec2(c*p.x + s*p.y, -s*p.x + c*p.y);
+}
+
+float modPolar(inout vec2 p, float repetitions) {
+  float angle = 2.0*PI/repetitions;
+  float a = atan(p.y, p.x) + angle/2.;
+  float r = length(p);
+  float c = floor(a/angle);
+  a = mod(a,angle) - angle/2.;
+  p = vec2(cos(a), sin(a))*r;
+  // For an odd number of repetitions, fix cell index of the cell in -x direction
+  // (cell index would be e.g. -5 and 5 in the two halves of the cell):
+  if (abs(c) >= (repetitions/2.0)) c = abs(c);
+  return c;
+}
+
+float pmin(float a, float b, float k) {
+  float h = clamp( 0.5+0.5*(b-a)/k, 0.0, 1.0 );
+  return mix( b, a, h ) - k*h*(1.0-h);
+}
+
+const vec2 sz       = vec2(1.0, sqrt(3.0));
+const vec2 hsz      = 0.5*sz;
+const float smallCount = 16.0;
+
+vec2 hextile(inout vec2 p) {
+  // See Art of Code: Hexagonal Tiling Explained!
+  // https://www.youtube.com/watch?v=VmrIDyYiJBA
+
+  vec2 p1 = mod(p, sz)-hsz;
+  vec2 p2 = mod(p - hsz*1.0, sz)-hsz;
+  vec2 p3 = mix(p2, p1, vec2(length(p1) < length(p2)));
+  vec2 n = p3 - p;
+  p = p3;
+
+  return n;
+}
+
+float circle(vec2 p, float r) {
+  return length(p) - r;
+}
+
+float box(vec2 p, vec2 b) {
+  vec2 d = abs(p)-b;
+  return length(max(d,0.0)) + min(max(d.x,d.y),0.0);
+}
+
+float unevenCapsule(vec2 p, float r1, float r2, float h) {
+  p.x = abs(p.x);
+  float b = (r1-r2)/h;
+  float a = sqrt(1.0-b*b);
+  float k = dot(p,vec2(-b,a));
+  if( k < 0.0 ) return length(p) - r1;
+  if( k > a*h ) return length(p-vec2(0.0,h)) - r2;
+  return dot(p, vec2(a,b) ) - r1;
+}
+
+float cogwheel(vec2 p, float innerRadius, float outerRadius, float cogs, float holes) {
+  float cogWidth  = 0.25*innerRadius*TAU/cogs;
+
+  float d0 = circle(p, innerRadius);
+
+  vec2 icp = p;
+  modPolar(icp, holes);
+  icp -= vec2(innerRadius*0.55, 0.0);
+  float d1 = circle(icp, innerRadius*0.25);
+
+  vec2 cp = p;
+  modPolar(cp, cogs);
+  cp -= vec2(innerRadius, 0.0);
+  float d2 = unevenCapsule(cp.yx, cogWidth, cogWidth*0.75, (outerRadius-innerRadius));
+
+  float d3 = circle(p, innerRadius*0.20);
+
+  float d = 1E6;
+  d = min(d, d0);
+  d = pmin(d, d2, 0.5*cogWidth);
+  d = min(d, d2);
+  d = max(d, -d1);
+  d = max(d, -d3);
+
+  return d;
+}
+
+float ccell1(vec2 p, float r) {
+  float d = 1E6;
+  const float bigCount = 60.0;
+
+  vec2 cp0 = p;
+  rot(cp0, -iTime*TAU/bigCount);
+  float d0 = cogwheel(cp0, 0.36, 0.38, bigCount, 5.0);
+
+  vec2 cp1 = p;
+  float nm = modPolar(cp1, 6.0);
+
+  cp1 -= vec2(0.5, 0.0);
+  rot(cp1, 0.2+TAU*nm/2.0 + iTime*TAU/smallCount);
+  float d1 = cogwheel(cp1, 0.11, 0.125, smallCount, 5.0);
+
+  d = min(d, d0);
+  d = min(d, d1);
+  return d;
+}
+
+float ccell2(vec2 p, float r) {
+  float d = 1E6;
+  vec2 cp0 = p;
+  float nm = modPolar(cp0, 6.0);
+  vec2 cp1 = cp0;
+  const float off = 0.275;
+  const float count = smallCount + 2.0;
+  cp0 -= vec2(off, 0.0);
+  rot(cp0, 0.+TAU*nm/2.0 - iTime*TAU/count);
+  float d0 = cogwheel(cp0, 0.09, 0.105, count, 5.0);
+
+
+  cp1 -= vec2(0.5, 0.0);
+  rot(cp1, 0.2+TAU*nm/2.0 + iTime*TAU/smallCount);
+  float d1 = cogwheel(cp1, 0.11, 0.125, smallCount, 5.0);
+
+  float l = length(p);
+  float d2 = l - (off+0.055);
+  float d3 = d2 + 0.020;;
+
+  vec2 tp0 = p;
+  modPolar(tp0, 60.0);
+  tp0.x -= off;
+  float d4 = box(tp0, vec2(0.0125, 0.005));
+
+  float ctime = -(iTime*0.05 + r)*TAU;
+
+  vec2 tp1 = p;
+  rot(tp1, ctime*12.0);
+  tp1.x -= 0.13;
+  float d5 = box(tp1, vec2(0.125, 0.005));
+
+  vec2 tp2 = p;
+  rot(tp2, ctime);
+  tp2.x -= 0.13*0.5;
+  float d6 = box(tp2, vec2(0.125*0.5, 0.0075));
+
+  float d7 = l - 0.025;
+  float d8 = l - 0.0125;
+
+  d = min(d, d0);
+  d = min(d, d1);
+  d = min(d, d2);
+  d = max(d, -d3);
+  d = min(d, d4);
+  d = min(d, d5);
+  d = min(d, d6);
+  d = min(d, d7);
+  d = max(d, -d8);
+
+  return d;
+}
+
+float df(vec2 p, float scale, inout vec2 nn) {
+  p /= scale;
+  nn = hextile(p);
+  nn = floor(nn + 0.5);
+  float r = hash(nn);
+
+  float d;;
+
+  if (r < 0.5) {
+    d = ccell1(p, r);
+  } else {
+    d = ccell2(p, r);
+  }
+
+  return d*scale;
+}
+
+vec3 postProcess(vec3 col, vec2 q)  {
+  //col = saturate(col);
+  col=pow(clamp(col,0.0,1.0),vec3(0.75));
+  col=col*0.6+0.4*col*col*(3.0-2.0*col);  // contrast
+  col=mix(col, vec3(dot(col, vec3(0.33))), -0.4);  // satuation
+  col*=0.5+0.5*pow(19.0*q.x*q.y*(1.0-q.x)*(1.0-q.y),0.7);  // vigneting
+  return col;
+}
+
+void mainImage(out vec4 fragColor, in vec2 fragCoord, in vec2 resolution, in vec2 uv) {
+  vec2 q = fragCoord/resolution.xy;
+  vec2 p = -1.0 + 2.0*q;
+  p.x *= resolution.x/resolution.y;
+  float tm = iTime*0.1;
+  p += vec2(cos(tm), sin(tm*sqrt(0.5)));
+  float z = mix(0.5, 1.0, pcos(tm*sqrt(0.3)));
+  float aa = 4.0 / resolution.y;
+
+  vec2 nn = vec2(0.0);
+  float d = df(p, z, nn);
+
+  vec3 col = vec3(160.0)/vec3(255.0);
+  vec3 baseCol = vec3(0.3);
+  vec4 logoCol = vec4(baseCol, 1.0)*smoothstep(-aa, 0.0, -d);
+  col = mix(col, logoCol.xyz, pow(logoCol.w, 8.0));
+  col += 0.4*pow(abs(sin(20.0*d)), 0.6);
+
+  col = postProcess(col, q);
+
+  fragColor = vec4(col, 1.0);
+}

demos/gtk-demo/crosswarp.glsl

@@ -0,0 +1,27 @@
+uniform float progress;
+uniform sampler2D u_texture1;
+uniform sampler2D u_texture2;
+
+vec4 getFromColor (vec2 uv) {
+  return GskTexture(u_texture1, uv);
+}
+
+vec4 getToColor (vec2 uv) {
+  return GskTexture(u_texture2, uv);
+}
+
+// Source: https://gl-transitions.com/editor/crosswarp
+// Author: Eke Péter <peterekepeter@gmail.com>
+// License: MIT
+
+vec4 transition(vec2 p) {
+  float x = progress;
+  x=smoothstep(.0,1.0,(x*2.0+p.x-1.0));
+  return mix(getFromColor((p-.5)*(1.-x)+.5), getToColor((p-.5)*x+.5), x);
+}
+
+
+void mainImage(out vec4 fragColor, in vec2 fragCoord, in vec2 resolution, in vec2 uv)
+{
+  fragColor = transition(uv);
+}

demos/gtk-demo/cursors.c

@@ -15,54 +15,12 @@ on_destroy (gpointer data)
   window = NULL;
 }
 
-static GdkTexture *
-cursor_callback (GdkCursor *cursor,
-                 int        cursor_size,
-                 double     scale,
-                 int       *width,
-                 int       *height,
-                 int       *hotspot_x,
-                 int       *hotspot_y,
-                 gpointer   data)
-{
-  GdkPixbuf *pixbuf;
-  GdkTexture *texture;
-  GError *error = NULL;
-  int scaled_size;
-
-  scaled_size = ceil (cursor_size * scale);
-
-  pixbuf = gdk_pixbuf_new_from_resource_at_scale ("/cursors/images/gtk-logo.svg",
-                                                  scaled_size, scaled_size,
-                                                  TRUE,
-                                                  &error);
-  if (!pixbuf)
-    {
-      g_print ("%s\n", error->message);
-      g_error_free (error);
-      return NULL;
-    }
-
-  texture = gdk_texture_new_for_pixbuf (pixbuf);
-
-  g_object_unref (pixbuf);
-
-  *width = cursor_size;
-  *height = cursor_size;
-  *hotspot_x = 18 * cursor_size / 32.0;
-  *hotspot_y = 2 * cursor_size / 32.0;
-
-  return texture;
-}
-
 GtkWidget *
 do_cursors (GtkWidget *do_widget)
 {
   if (!window)
     {
       GtkBuilder *builder;
-      GtkWidget *logo_callback;
-      GdkCursor *cursor;
 
       builder = gtk_builder_new_from_resource ("/cursors/cursors.ui");
       window = GTK_WIDGET (gtk_builder_get_object (builder, "window"));
@@ -71,10 +29,6 @@ do_cursors (GtkWidget *do_widget)
                               gtk_widget_get_display (do_widget));
       g_signal_connect (window, "destroy",
                         G_CALLBACK (on_destroy), NULL);
-      logo_callback = GTK_WIDGET (gtk_builder_get_object (builder, "logo_callback"));
-      cursor = gdk_cursor_new_from_callback (cursor_callback, NULL, NULL, NULL);
-      gtk_widget_set_cursor (logo_callback, cursor);
-      g_object_unref (cursor);
       g_object_unref (builder);
     }
 

demos/gtk-demo/demo.gresource.xml

@@ -116,7 +116,6 @@
     <file>w_resize_cursor.png</file>
     <file>zoom_in_cursor.png</file>
     <file>zoom_out_cursor.png</file>
-    <file>gtk-logo.svg</file>
   </gresource>
   <gresource prefix="/dnd">
     <file>dnd.css</file>
@@ -146,6 +145,21 @@
     <file>cogs.glsl</file>
     <file>glowingstars.glsl</file>
   </gresource>
+  <gresource prefix="/gltransition">
+    <file>gtkshaderstack.c</file>
+    <file>gtkshaderstack.h</file>
+    <file>gtkshaderbin.h</file>
+    <file>gtkshaderbin.c</file>
+    <file>gskshaderpaintable.h</file>
+    <file>gskshaderpaintable.c</file>
+    <file>wind.glsl</file>
+    <file>radial.glsl</file>
+    <file>crosswarp.glsl</file>
+    <file>kaleidoscope.glsl</file>
+    <file>cogs2.glsl</file>
+    <file>ripple.glsl</file>
+    <file>background.glsl</file>
+  </gresource>
   <gresource prefix="/iconscroll">
     <file>iconscroll.ui</file>
   </gresource>
@@ -281,6 +295,7 @@
     <file>gears.c</file>
     <file>gestures.c</file>
     <file>glarea.c</file>
+    <file>gltransition.c</file>
     <file>headerbar.c</file>
     <file>hypertext.c</file>
     <file>iconscroll.c</file>
@@ -438,10 +453,6 @@
     <file>icons/16x16/categories/applications-other.png</file>
     <file>icons/48x48/status/starred.png</file>
     <file alias="icons/scalable/apps/org.gtk.Demo4.svg">data/scalable/apps/org.gtk.Demo4.svg</file>
-    <file>portland-rose-thumbnail.png</file>
-    <file>large-image-thumbnail.png</file>
-    <file compressed="true">large-image.png</file>
-    <file compressed="true">Moby-Dick.txt</file>
   </gresource>
   <gresource prefix="/org/gtk/Demo4/gtk">
     <file preprocess="xml-stripblanks">help-overlay.ui</file>

demos/gtk-demo/errorstates.c

@@ -55,7 +55,7 @@ mode_switch_state_set (GtkSwitch *sw,
     {
       gtk_widget_set_visible (label, TRUE);
       gtk_accessible_update_relation (GTK_ACCESSIBLE (sw),
-                                      GTK_ACCESSIBLE_RELATION_ERROR_MESSAGE, label, NULL,
+                                      GTK_ACCESSIBLE_RELATION_ERROR_MESSAGE, label,
                                       -1);
       gtk_accessible_update_state (GTK_ACCESSIBLE (sw),
                                    GTK_ACCESSIBLE_STATE_INVALID, GTK_ACCESSIBLE_INVALID_TRUE,

demos/gtk-demo/fishbowl.c

@@ -9,6 +9,7 @@
 
 #include "gtkfishbowl.h"
 #include "gtkgears.h"
+#include "gskshaderpaintable.h"
 
 #include "nodewidget.h"
 #include "graphwidget.h"
@@ -151,6 +152,44 @@ create_switch (void)
   return w;
 }
 
+static gboolean
+update_paintable (GtkWidget     *widget,
+                  GdkFrameClock *frame_clock,
+                  gpointer       user_data)
+{
+  GskShaderPaintable *paintable;
+  gint64 frame_time;
+
+  paintable = GSK_SHADER_PAINTABLE (gtk_picture_get_paintable (GTK_PICTURE (widget)));
+  frame_time = gdk_frame_clock_get_frame_time (frame_clock);
+  gsk_shader_paintable_update_time (paintable, 0, frame_time);
+
+  return G_SOURCE_CONTINUE;
+}
+
+static GtkWidget *
+create_cogs (void)
+{
+  GtkWidget *picture;
+  static GskGLShader *cog_shader = NULL;
+  GdkPaintable *paintable;
+
+ if (cog_shader == NULL)
+    cog_shader = gsk_gl_shader_new_from_resource ("/gltransition/cogs2.glsl");
+  paintable = gsk_shader_paintable_new (g_object_ref (cog_shader), NULL);
+  picture = gtk_picture_new_for_paintable (paintable);
+  gtk_widget_set_size_request (picture, 150, 75);
+  gtk_widget_add_tick_callback (picture, update_paintable, NULL, NULL);
+
+  return picture;
+}
+
+static gboolean
+check_cogs (GtkFishbowl *fb)
+{
+  return GSK_IS_GL_RENDERER (gtk_native_get_renderer (gtk_widget_get_native (GTK_WIDGET (fb))));
+}
+
 static void
 mapped (GtkWidget *w)
 {
@@ -200,6 +239,7 @@ static const struct {
   { "Gears",      create_gears,          NULL },
   { "Switch",     create_switch,         NULL },
   { "Menubutton", create_menu_button,    NULL },
+  { "Shader",     create_cogs,           check_cogs },
   { "Tiger",      create_tiger,          NULL },
   { "Graph",      create_graph,          NULL },
 };

demos/gtk-demo/fontify.c

@@ -363,9 +363,7 @@ insert_markup_idle (gpointer data)
 
       if (g_get_monotonic_time () - begin > G_TIME_SPAN_MILLISECOND)
         {
-          guint id;
-          id = g_idle_add (insert_markup_idle, data);
-          g_source_set_name_by_id (id, "[gtk-demo] insert_markup_idle");
+          g_idle_add (insert_markup_idle, data);
           return G_SOURCE_REMOVE;
         }
 
@@ -400,9 +398,7 @@ parse_markup_idle (gpointer data)
   do {
     if (g_get_monotonic_time () - begin > G_TIME_SPAN_MILLISECOND)
       {
-        guint id;
-        id = g_idle_add (parse_markup_idle, data);
-        g_source_set_name_by_id (id, "[gtk-demo] parse_markup_idle");
+        g_idle_add (parse_markup_idle, data);
         return G_SOURCE_REMOVE;
       }
 

demos/gtk-demo/fontplane.c

@@ -276,7 +276,7 @@ gtk_font_plane_class_init (GtkFontPlaneClass *class)
 
 GtkWidget *
 gtk_font_plane_new (GtkAdjustment *weight_adj,
-                    GtkAdjustment *width_adj)
+                     GtkAdjustment *width_adj)
 {
   return g_object_new (GTK_TYPE_FONT_PLANE,
                        "weight-adjustment", weight_adj,

demos/gtk-demo/fontplane.h

@@ -55,7 +55,7 @@ struct _GtkFontPlaneClass
 
 
 GType       gtk_font_plane_get_type (void) G_GNUC_CONST;
-GtkWidget * gtk_font_plane_new      (GtkAdjustment *weight_adj,
-                                     GtkAdjustment *width_adj);
+GtkWidget * gtk_font_plane_new      (GtkAdjustment *width_adj,
+                                     GtkAdjustment *weight_adj);
 
 G_END_DECLS

demos/gtk-demo/gltransition.c

@@ -0,0 +1,362 @@
+/* OpenGL/Transitions and Effects
+ * #Keywords: OpenGL, shader, effect
+ *
+ * Create transitions between pages using a custom fragment shader.
+ *
+ * The example transitions here are taken from gl-transitions.com, and you
+ * can edit the shader code itself on the last page of the stack.
+ *
+ * The transitions work with arbitrary content. We use images, shaders
+ * GL areas and plain old widgets to demonstrate this.
+ *
+ * The demo also shows some over-the-top effects like wobbly widgets,
+ * and animated backgrounds.
+ */
+
+#include <math.h>
+#include <gtk/gtk.h>
+#include "gtkshaderstack.h"
+#include "gtkshaderbin.h"
+#include "gtkshadertoy.h"
+#include "gskshaderpaintable.h"
+
+static GtkWidget *demo_window = NULL;
+
+static void
+close_window (GtkWidget *widget)
+{
+  /* Reset the state */
+  demo_window = NULL;
+}
+
+static void
+text_changed (GtkTextBuffer *buffer,
+              GtkWidget     *button)
+{
+  gtk_widget_set_visible (button, TRUE);
+}
+
+static void
+apply_text (GtkWidget     *button,
+            GtkTextBuffer *buffer)
+{
+  GtkWidget *stack;
+  GskGLShader *shader;
+  GtkTextIter start, end;
+  char *text;
+
+  stack = g_object_get_data (G_OBJECT (button), "the-stack");
+
+  gtk_text_buffer_get_bounds (buffer, &start, &end);
+  text = gtk_text_buffer_get_text (buffer, &start, &end, TRUE);
+
+  GBytes *bytes = g_bytes_new_take (text, strlen (text));
+  shader = gsk_gl_shader_new_from_bytes (bytes);
+
+  gtk_shader_stack_set_shader (GTK_SHADER_STACK (stack), shader);
+
+  g_object_unref (shader);
+  g_bytes_unref (bytes);
+
+  gtk_widget_set_visible (button, FALSE);
+}
+
+static void
+go_back (GtkWidget     *button,
+         GtkWidget     *stack)
+{
+  gtk_shader_stack_transition (GTK_SHADER_STACK (stack), FALSE);
+}
+
+static void
+go_forward (GtkWidget     *button,
+            GtkWidget     *stack)
+{
+  gtk_shader_stack_transition (GTK_SHADER_STACK (stack), TRUE);
+}
+
+static void
+clicked_cb (GtkGestureClick *gesture,
+            guint            n_pressed,
+            double           x,
+            double           y,
+            gpointer         data)
+{
+  gtk_gesture_set_state (GTK_GESTURE (gesture), GTK_EVENT_SEQUENCE_CLAIMED);
+}
+
+static GtkWidget *
+ripple_bin_new (void)
+{
+  GtkWidget *bin = gtk_shader_bin_new ();
+  static GskGLShader *shader = NULL;
+
+  if (shader == NULL)
+    shader = gsk_gl_shader_new_from_resource ("/gltransition/ripple.glsl");
+
+  gtk_shader_bin_add_shader (GTK_SHADER_BIN (bin), shader, GTK_STATE_FLAG_PRELIGHT, GTK_STATE_FLAG_PRELIGHT, 20);
+
+  return bin;
+}
+
+static GtkWidget *
+new_shadertoy (const char *path)
+{
+  GBytes *shader;
+  GtkWidget *toy;
+
+  toy = gtk_shadertoy_new ();
+  shader = g_resources_lookup_data (path, 0, NULL);
+  gtk_shadertoy_set_image_shader (GTK_SHADERTOY (toy),
+                                  g_bytes_get_data (shader, NULL));
+  g_bytes_unref (shader);
+
+  return toy;
+}
+
+static gboolean
+update_paintable (GtkWidget     *widget,
+                  GdkFrameClock *frame_clock,
+                  gpointer       user_data)
+{
+  GskShaderPaintable *paintable;
+  gint64 frame_time;
+
+  paintable = GSK_SHADER_PAINTABLE (gtk_picture_get_paintable (GTK_PICTURE (widget)));
+  frame_time = gdk_frame_clock_get_frame_time (frame_clock);
+  gsk_shader_paintable_update_time (paintable, 0, frame_time);
+
+  return G_SOURCE_CONTINUE;
+}
+
+static GtkWidget *
+make_shader_stack (const char *name,
+                   const char *resource_path,
+                   int active_child,
+                   GtkWidget  *scale)
+{
+  GtkWidget *stack, *child, *widget, *vbox, *hbox, *bin;
+  GtkWidget *label, *button, *tv;
+  GskGLShader *shader;
+  GObjectClass *class;
+  GParamSpecFloat *pspec;
+  GtkAdjustment *adjustment;
+  GtkTextBuffer *buffer;
+  GBytes *bytes;
+  GtkEventController *controller;
+  GdkPaintable *paintable;
+
+  stack = gtk_shader_stack_new ();
+  shader = gsk_gl_shader_new_from_resource (resource_path);
+  gtk_shader_stack_set_shader (GTK_SHADER_STACK (stack), shader);
+  g_object_unref (shader);
+
+  child = gtk_picture_new_for_resource ("/css_blendmodes/ducky.png");
+  gtk_picture_set_can_shrink (GTK_PICTURE (child), TRUE);
+  gtk_shader_stack_add_child (GTK_SHADER_STACK (stack), child);
+
+  shader = gsk_gl_shader_new_from_resource ("/gltransition/cogs2.glsl");
+  paintable = gsk_shader_paintable_new (shader, NULL);
+
+  child = gtk_picture_new_for_paintable (paintable);
+  gtk_widget_add_tick_callback (child, update_paintable, NULL, NULL);
+  gtk_picture_set_can_shrink (GTK_PICTURE (child), TRUE);
+  gtk_shader_stack_add_child (GTK_SHADER_STACK (stack), child);
+
+  child = gtk_picture_new_for_resource ("/transparent/portland-rose.jpg");
+  gtk_picture_set_can_shrink (GTK_PICTURE (child), TRUE);
+  gtk_shader_stack_add_child (GTK_SHADER_STACK (stack), child);
+
+  child = new_shadertoy ("/shadertoy/neon.glsl");
+  gtk_shader_stack_add_child (GTK_SHADER_STACK (stack), child);
+
+  child = gtk_box_new (GTK_ORIENTATION_VERTICAL, 6);
+
+  class = g_type_class_ref (GTK_TYPE_SHADER_STACK);
+  pspec = G_PARAM_SPEC_FLOAT (g_object_class_find_property (class, "duration"));
+
+  adjustment = gtk_range_get_adjustment (GTK_RANGE (scale));
+  if (gtk_adjustment_get_lower (adjustment) == 0.0 &&
+      gtk_adjustment_get_upper (adjustment) == 0.0)
+    {
+      gtk_adjustment_configure (adjustment,
+                                pspec->default_value,
+                                pspec->minimum,
+                                pspec->maximum,
+                                0.1, 0.5, 0);
+    }
+
+  g_type_class_unref (class);
+
+  g_object_bind_property (adjustment, "value",
+                          stack, "duration",
+                          G_BINDING_DEFAULT);
+
+  widget = gtk_scrolled_window_new ();
+  gtk_scrolled_window_set_has_frame (GTK_SCROLLED_WINDOW (widget), TRUE);
+  gtk_widget_set_hexpand (widget, TRUE);
+  gtk_widget_set_vexpand (widget, TRUE);
+
+  controller = GTK_EVENT_CONTROLLER (gtk_gesture_click_new ());
+  gtk_gesture_single_set_button (GTK_GESTURE_SINGLE (controller), 0);
+  g_signal_connect (controller, "released", G_CALLBACK (clicked_cb), NULL);
+  gtk_event_controller_set_propagation_phase (controller, GTK_PHASE_BUBBLE);
+  gtk_widget_add_controller (GTK_WIDGET (widget), controller);
+
+  tv = gtk_text_view_new ();
+  gtk_text_view_set_left_margin (GTK_TEXT_VIEW (tv), 4);
+  gtk_text_view_set_right_margin (GTK_TEXT_VIEW (tv), 4);
+  gtk_text_view_set_top_margin (GTK_TEXT_VIEW (tv), 4);
+  gtk_text_view_set_bottom_margin (GTK_TEXT_VIEW (tv), 4);
+  buffer = gtk_text_view_get_buffer (GTK_TEXT_VIEW (tv));
+  bytes = g_resources_lookup_data (resource_path, 0, NULL);
+  gtk_text_buffer_set_text (buffer,
+                            (const char *)g_bytes_get_data (bytes, NULL),
+                            g_bytes_get_size (bytes));
+  g_bytes_unref (bytes);
+  gtk_scrolled_window_set_child (GTK_SCROLLED_WINDOW (widget), tv);
+
+  gtk_box_append (GTK_BOX (child), widget);
+
+  gtk_shader_stack_add_child (GTK_SHADER_STACK (stack), child);
+
+  gtk_shader_stack_set_active (GTK_SHADER_STACK (stack), active_child);
+
+  vbox = gtk_box_new (GTK_ORIENTATION_VERTICAL, 6);
+
+  widget = gtk_center_box_new ();
+  label = gtk_label_new (name);
+  gtk_widget_add_css_class (label, "title-4");
+  gtk_widget_set_size_request (label, -1, 26);
+  gtk_center_box_set_center_widget (GTK_CENTER_BOX (widget), label);
+
+  button = gtk_button_new_from_icon_name ("view-refresh-symbolic");
+  g_signal_connect (buffer, "changed", G_CALLBACK (text_changed), button);
+  g_object_set_data (G_OBJECT (button), "the-stack", stack);
+  g_signal_connect (button, "clicked", G_CALLBACK (apply_text), buffer);
+  gtk_widget_set_halign (button, GTK_ALIGN_CENTER);
+  gtk_widget_set_valign (button, GTK_ALIGN_CENTER);
+  gtk_widget_add_css_class (button, "small");
+  gtk_widget_set_visible (button, FALSE);
+  gtk_center_box_set_end_widget (GTK_CENTER_BOX (widget), button);
+
+  gtk_box_append (GTK_BOX (vbox), widget);
+
+  GtkWidget *bin2 = ripple_bin_new ();
+  gtk_shader_bin_set_child (GTK_SHADER_BIN (bin2), stack);
+
+  gtk_box_append (GTK_BOX (vbox), bin2);
+
+  hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 6);
+  gtk_widget_set_halign (hbox, GTK_ALIGN_CENTER);
+
+  gtk_box_append (GTK_BOX (vbox), hbox);
+
+  button = gtk_button_new_from_icon_name ("go-previous-symbolic");
+  g_signal_connect (button, "clicked", G_CALLBACK (go_back), stack);
+  bin = ripple_bin_new ();
+  gtk_shader_bin_set_child (GTK_SHADER_BIN (bin), button);
+  gtk_box_append (GTK_BOX (hbox), bin);
+
+  button = gtk_button_new_from_icon_name ("go-next-symbolic");
+  g_signal_connect (button, "clicked", G_CALLBACK (go_forward), stack);
+  bin = ripple_bin_new ();
+  gtk_shader_bin_set_child (GTK_SHADER_BIN (bin), button);
+  gtk_box_append (GTK_BOX (hbox), bin);
+
+  return vbox;
+}
+
+static void
+remove_provider (gpointer data)
+{
+  GtkStyleProvider *provider = GTK_STYLE_PROVIDER (data);
+
+  gtk_style_context_remove_provider_for_display (gdk_display_get_default (), provider);
+  g_object_unref (provider);
+}
+
+static GtkWidget *
+create_gltransition_window (GtkWidget *do_widget)
+{
+  GtkWidget *window, *headerbar, *scale, *outer_grid, *grid, *background;
+  GdkPaintable *paintable;
+  GtkCssProvider *provider;
+
+  window = gtk_window_new ();
+  gtk_window_set_display (GTK_WINDOW (window),  gtk_widget_get_display (do_widget));
+  gtk_window_set_title (GTK_WINDOW (window), "Transitions and Effects");
+  headerbar = gtk_header_bar_new ();
+  scale = gtk_scale_new (GTK_ORIENTATION_HORIZONTAL, NULL);
+  gtk_scale_set_draw_value (GTK_SCALE (scale), FALSE);
+  gtk_widget_set_size_request (scale, 100, -1);
+  gtk_widget_set_tooltip_text (scale, "Transition duration");
+  gtk_header_bar_pack_end (GTK_HEADER_BAR (headerbar), scale);
+  gtk_window_set_titlebar (GTK_WINDOW (window), headerbar);
+  gtk_window_set_default_size (GTK_WINDOW (window), 800, 600);
+  g_signal_connect (window, "destroy", G_CALLBACK (close_window), NULL);
+
+  outer_grid = gtk_grid_new ();
+  gtk_window_set_child (GTK_WINDOW (window), outer_grid);
+
+  paintable = gsk_shader_paintable_new (gsk_gl_shader_new_from_resource ("/gltransition/background.glsl"), NULL);
+  background = gtk_picture_new_for_paintable (paintable);
+  gtk_widget_add_tick_callback (background, update_paintable, NULL, NULL);
+
+  gtk_grid_attach (GTK_GRID (outer_grid),
+                   background,
+                   0, 0, 1, 1);
+
+  grid = gtk_grid_new ();
+  gtk_grid_attach (GTK_GRID (outer_grid),
+                   grid,
+                   0, 0, 1, 1);
+
+  gtk_widget_set_halign (grid, GTK_ALIGN_CENTER);
+  gtk_widget_set_valign (grid, GTK_ALIGN_CENTER);
+  gtk_widget_set_margin_start (grid, 12);
+  gtk_widget_set_margin_end (grid, 12);
+  gtk_widget_set_margin_top (grid, 12);
+  gtk_widget_set_margin_bottom (grid, 12);
+  gtk_grid_set_row_spacing (GTK_GRID (grid), 6);
+  gtk_grid_set_column_spacing (GTK_GRID (grid), 6);
+  gtk_grid_set_row_homogeneous (GTK_GRID (grid), TRUE);
+  gtk_grid_set_column_homogeneous (GTK_GRID (grid), TRUE);
+
+  gtk_grid_attach (GTK_GRID (grid),
+                   make_shader_stack ("Wind", "/gltransition/wind.glsl", 0, scale),
+                   0, 0, 1, 1);
+  gtk_grid_attach (GTK_GRID (grid),
+                   make_shader_stack ("Radial", "/gltransition/radial.glsl", 1, scale),
+                   1, 0, 1, 1);
+  gtk_grid_attach (GTK_GRID (grid),
+                   make_shader_stack ("Crosswarp", "/gltransition/crosswarp.glsl", 2, scale),
+                   0, 1, 1, 1);
+  gtk_grid_attach (GTK_GRID (grid),
+                   make_shader_stack ("Kaleidoscope", "/gltransition/kaleidoscope.glsl", 3, scale),
+                   1, 1, 1, 1);
+
+  provider = gtk_css_provider_new ();
+  gtk_css_provider_load_from_string (provider, "button.small { padding: 0; }");
+  gtk_style_context_add_provider_for_display (gdk_display_get_default (),
+                                              GTK_STYLE_PROVIDER (provider),
+                                              GTK_STYLE_PROVIDER_PRIORITY_APPLICATION);
+
+  g_object_set_data_full (G_OBJECT (window), "provider", provider, remove_provider);
+
+  return window;
+}
+
+GtkWidget *
+do_gltransition (GtkWidget *do_widget)
+{
+  if (!demo_window)
+    demo_window = create_gltransition_window (do_widget);
+
+  if (!gtk_widget_get_visible (demo_window))
+    gtk_widget_set_visible (demo_window, TRUE);
+  else
+    gtk_window_destroy (GTK_WINDOW (demo_window));
+
+  return demo_window;
+}

demos/gtk-demo/gskshaderpaintable.c

@@ -0,0 +1,334 @@
+/*
+ * Copyright © 2020 Red Hat, Inc
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library. If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Authors: Matthias Clasen <mclasen@redhat.com>
+ */
+
+#include "config.h"
+
+#include <gtk/gtk.h>
+#include "gskshaderpaintable.h"
+
+/**
+ * GskShaderPaintable:
+ *
+ * `GskShaderPaintable` is an implementation of the `GdkPaintable` interface
+ * that uses a `GskGLShader` to create pixels.
+ *
+ * You can set the uniform data that the shader needs for rendering
+ * using gsk_shader_paintable_set_args(). This function can
+ * be called repeatedly to change the uniform data for the next
+ * snapshot.
+ *
+ * Commonly, time is passed to shaders as a float uniform containing
+ * the elapsed time in seconds. The convenience API
+ * gsk_shader_paintable_update_time() can be called from a `GtkTickCallback`
+ * to update the time based on the frame time of the frame clock.
+ */
+
+
+struct _GskShaderPaintable
+{
+  GObject parent_instance;
+
+  GskGLShader *shader;
+  GBytes *args;
+
+  gint64 start_time;
+};
+
+struct _GskShaderPaintableClass
+{
+  GObjectClass parent_class;
+};
+
+enum {
+  PROP_0,
+  PROP_SHADER,
+  PROP_ARGS,
+
+  N_PROPS,
+};
+
+static GParamSpec *properties[N_PROPS] = { NULL, };
+
+static void
+gsk_shader_paintable_paintable_snapshot (GdkPaintable *paintable,
+                                         GdkSnapshot  *snapshot,
+                                         double        width,
+                                         double        height)
+{
+  GskShaderPaintable *self = GSK_SHADER_PAINTABLE (paintable);
+
+  gtk_snapshot_push_gl_shader (snapshot, self->shader, &GRAPHENE_RECT_INIT(0, 0, width, height), g_bytes_ref (self->args));
+  gtk_snapshot_pop (snapshot);
+}
+
+static void
+gsk_shader_paintable_paintable_init (GdkPaintableInterface *iface)
+{
+  iface->snapshot = gsk_shader_paintable_paintable_snapshot;
+}
+
+G_DEFINE_TYPE_EXTENDED (GskShaderPaintable, gsk_shader_paintable, G_TYPE_OBJECT, 0,
+                        G_IMPLEMENT_INTERFACE (GDK_TYPE_PAINTABLE,
+                                               gsk_shader_paintable_paintable_init))
+
+static void
+gsk_shader_paintable_set_property (GObject      *object,
+                                   guint         prop_id,
+                                   const GValue *value,
+                                   GParamSpec   *pspec)
+
+{
+  GskShaderPaintable *self = GSK_SHADER_PAINTABLE (object);
+
+  switch (prop_id)
+    {
+    case PROP_SHADER:
+      gsk_shader_paintable_set_shader (self, g_value_get_object (value));
+      break;
+
+    case PROP_ARGS:
+      gsk_shader_paintable_set_args (self, g_value_get_boxed (value));
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+      break;
+    }
+}
+
+static void
+gsk_shader_paintable_get_property (GObject    *object,
+                                   guint       prop_id,
+                                   GValue     *value,
+                                   GParamSpec *pspec)
+{
+  GskShaderPaintable *self = GSK_SHADER_PAINTABLE (object);
+
+  switch (prop_id)
+    {
+    case PROP_SHADER:
+      g_value_set_object (value, self->shader);
+      break;
+
+    case PROP_ARGS:
+      g_value_set_boxed (value, self->args);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+      break;
+    }
+}
+
+static void
+gsk_shader_paintable_finalize (GObject *object)
+{
+  GskShaderPaintable *self = GSK_SHADER_PAINTABLE (object);
+
+  g_clear_pointer (&self->args, g_bytes_unref);
+  g_clear_object (&self->shader);
+
+  G_OBJECT_CLASS (gsk_shader_paintable_parent_class)->finalize (object);
+}
+
+static void
+gsk_shader_paintable_class_init (GskShaderPaintableClass *klass)
+{
+  GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
+
+  gobject_class->get_property = gsk_shader_paintable_get_property;
+  gobject_class->set_property = gsk_shader_paintable_set_property;
+  gobject_class->finalize = gsk_shader_paintable_finalize;
+
+  properties[PROP_SHADER] =
+    g_param_spec_object ("shader", "Shader", "The shader",
+                         GSK_TYPE_GL_SHADER,
+                         G_PARAM_READWRITE | G_PARAM_EXPLICIT_NOTIFY | G_PARAM_STATIC_STRINGS);
+
+  properties[PROP_ARGS] =
+    g_param_spec_boxed ("args", "Arguments", "The uniform arguments",
+                        G_TYPE_BYTES,
+                        G_PARAM_READWRITE | G_PARAM_EXPLICIT_NOTIFY | G_PARAM_STATIC_STRINGS);
+
+  g_object_class_install_properties (gobject_class, N_PROPS, properties);
+}
+
+static void
+gsk_shader_paintable_init (GskShaderPaintable *self)
+{
+}
+
+/**
+ * gsk_shader_paintable_new:
+ * @shader: (transfer full) (nullable): the shader to use
+ * @data: (transfer full) (nullable): uniform data
+ *
+ * Creates a paintable that uses the @shader to create
+ * pixels. The shader must not require input textures.
+ * If @data is %NULL, all uniform values are set to zero.
+ *
+ * Returns: (transfer full): a new `GskShaderPaintable`
+ */
+GdkPaintable *
+gsk_shader_paintable_new (GskGLShader *shader,
+                          GBytes      *data)
+{
+  GdkPaintable *ret;
+
+  g_return_val_if_fail (shader == NULL || GSK_IS_GL_SHADER (shader), NULL);
+
+  if (shader && !data)
+    {
+      int size = gsk_gl_shader_get_args_size (shader);
+      data = g_bytes_new_take (g_new0 (guchar, size), size);
+    }
+
+  ret = g_object_new (GSK_TYPE_SHADER_PAINTABLE,
+                      "shader", shader,
+                      "args", data,
+                      NULL);
+
+  g_clear_object (&shader);
+  g_clear_pointer (&data, g_bytes_unref);
+
+  return ret;
+}
+
+/**
+ * gsk_shader_paintable_set_shader:
+ * @self: a `GskShaderPaintable`
+ * @shader: the `GskGLShader` to use
+ *
+ * Sets the shader that the paintable will use
+ * to create pixels. The shader must not require
+ * input textures.
+ */
+void
+gsk_shader_paintable_set_shader (GskShaderPaintable *self,
+                                 GskGLShader        *shader)
+{
+  g_return_if_fail (GSK_IS_SHADER_PAINTABLE (self));
+  g_return_if_fail (shader == NULL || GSK_IS_GL_SHADER (shader));
+  g_return_if_fail (shader == NULL || gsk_gl_shader_get_n_textures (shader) == 0);
+
+  if (!g_set_object (&self->shader, shader))
+    return;
+
+  g_object_notify_by_pspec (G_OBJECT (self), properties[PROP_SHADER]);
+  gdk_paintable_invalidate_contents (GDK_PAINTABLE (self));
+
+  g_clear_pointer (&self->args, g_bytes_unref);
+}
+
+/**
+ * gsk_shader_paintable_get_shader:
+ * @self: a `GskShaderPaintable`
+ *
+ * Returns the shader that the paintable is using.
+ *
+ * Returns: (transfer none): the `GskGLShader` that is used
+ */
+GskGLShader *
+gsk_shader_paintable_get_shader (GskShaderPaintable *self)
+{
+  g_return_val_if_fail (GSK_IS_SHADER_PAINTABLE (self), NULL);
+
+  return self->shader;
+}
+
+/**
+ * gsk_shader_paintable_set_args:
+ * @self: a `GskShaderPaintable`
+ * @data: Data block with uniform data for the shader
+ *
+ * Sets the uniform data that will be passed to the
+ * shader when rendering. The @data will typically
+ * be produced by a `GskUniformDataBuilder`.
+ *
+ * Note that the @data should be considered immutable
+ * after it has been passed to this function.
+ */
+void
+gsk_shader_paintable_set_args (GskShaderPaintable *self,
+                                       GBytes             *data)
+{
+  g_return_if_fail (GSK_IS_SHADER_PAINTABLE (self));
+  g_return_if_fail (data == NULL || g_bytes_get_size (data) == gsk_gl_shader_get_args_size (self->shader));
+
+  g_clear_pointer (&self->args, g_bytes_unref);
+  if (data)
+    self->args = g_bytes_ref (data);
+
+  g_object_notify_by_pspec (G_OBJECT (self), properties[PROP_ARGS]);
+  gdk_paintable_invalidate_contents (GDK_PAINTABLE (self));
+}
+
+/**
+ * gsk_shader_paintable_get_args:
+ * @self: a `GskShaderPaintable`
+ *
+ * Returns the uniform data set with
+ * gsk_shader_paintable_get_args().
+ *
+ * Returns: (transfer none): the uniform data
+ */
+GBytes *
+gsk_shader_paintable_get_args (GskShaderPaintable *self)
+{
+  g_return_val_if_fail (GSK_IS_SHADER_PAINTABLE (self), NULL);
+
+  return self->args;
+}
+
+/**
+ * gsk_shader_paintable_update_time:
+ * @self: a `GskShaderPaintable`
+ * @time_idx: the index of the uniform for time in seconds as float
+ * @frame_time: the current frame time, as returned by `GdkFrameClock`
+ *
+ * This function is a convenience wrapper for
+ * gsk_shader_paintable_set_args() that leaves all
+ * uniform values unchanged, except for the uniform with
+ * index @time_idx, which will be set to the elapsed time
+ * in seconds, since the first call to this function.
+ *
+ * This function is usually called from a `GtkTickCallback`.
+ */
+void
+gsk_shader_paintable_update_time (GskShaderPaintable *self,
+                                  int                 time_idx,
+                                  gint64              frame_time)
+{
+  GskShaderArgsBuilder *builder;
+  GBytes *args;
+  float time;
+
+  if (self->start_time == 0)
+    self->start_time = frame_time;
+
+  time = (frame_time - self->start_time) / (float)G_TIME_SPAN_SECOND;
+
+  builder = gsk_shader_args_builder_new (self->shader, self->args);
+  gsk_shader_args_builder_set_float (builder, time_idx, time);
+  args = gsk_shader_args_builder_free_to_args (builder);
+
+  gsk_shader_paintable_set_args (self, args);
+
+  g_bytes_unref (args);
+}

demos/gtk-demo/gskshaderpaintable.h

@@ -0,0 +1,43 @@
+/*
+ * Copyright © 2020 Red Hat, Inc.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library. If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Authors: Matthias Clasen <mclasen@redhat.com>
+ */
+
+#pragma once
+
+#include <gdk/gdk.h>
+#include <gsk/gsk.h>
+
+G_BEGIN_DECLS
+
+#define GSK_TYPE_SHADER_PAINTABLE (gsk_shader_paintable_get_type ())
+
+G_DECLARE_FINAL_TYPE (GskShaderPaintable, gsk_shader_paintable, GSK, SHADER_PAINTABLE, GObject)
+
+GdkPaintable *   gsk_shader_paintable_new              (GskGLShader        *shader,
+                                                        GBytes             *data);
+
+GskGLShader *    gsk_shader_paintable_get_shader       (GskShaderPaintable *self);
+void             gsk_shader_paintable_set_shader       (GskShaderPaintable *self,
+                                                        GskGLShader        *shader);
+GBytes *         gsk_shader_paintable_get_args         (GskShaderPaintable *self);
+void             gsk_shader_paintable_set_args         (GskShaderPaintable *self,
+                                                        GBytes             *data);
+void             gsk_shader_paintable_update_time      (GskShaderPaintable *self,
+                                                        int                 time_idx,
+                                                        gint64              frame_time);
+G_END_DECLS

demos/gtk-demo/gtk-logo.svg

@@ -1,138 +0,0 @@
-<?xml version="1.0" encoding="UTF-8" standalone="no"?>
-<!-- Created with Inkscape (http://www.inkscape.org/) -->
-
-<svg
-   xmlns:dc="http://purl.org/dc/elements/1.1/"
-   xmlns:cc="http://creativecommons.org/ns#"
-   xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
-   xmlns:svg="http://www.w3.org/2000/svg"
-   xmlns="http://www.w3.org/2000/svg"
-   xmlns:sodipodi="http://sodipodi.sourceforge.net/DTD/sodipodi-0.dtd"
-   xmlns:inkscape="http://www.inkscape.org/namespaces/inkscape"
-   width="128"
-   height="128"
-   id="svg6843"
-   sodipodi:version="0.32"
-   inkscape:version="0.92.4 5da689c313, 2019-01-14"
-   version="1.0"
-   sodipodi:docname="gtk-logo.svg"
-   inkscape:output_extension="org.inkscape.output.svg.inkscape"
-   inkscape:export-filename="/home/ebassi/Pictures/gtk-logo-256.png"
-   inkscape:export-xdpi="192"
-   inkscape:export-ydpi="192">
-  <defs
-     id="defs6845">
-    <inkscape:perspective
-       sodipodi:type="inkscape:persp3d"
-       inkscape:vp_x="-50 : 600 : 1"
-       inkscape:vp_y="0 : 1000 : 0"
-       inkscape:vp_z="700 : 600 : 1"
-       inkscape:persp3d-origin="300 : 400 : 1"
-       id="perspective13" />
-  </defs>
-  <sodipodi:namedview
-     id="base"
-     pagecolor="#ffffff"
-     bordercolor="#666666"
-     borderopacity="1.0"
-     inkscape:pageopacity="0"
-     inkscape:pageshadow="2"
-     inkscape:zoom="2.8284271"
-     inkscape:cx="69.874353"
-     inkscape:cy="64.313526"
-     inkscape:current-layer="layer1"
-     showgrid="false"
-     inkscape:document-units="px"
-     inkscape:grid-bbox="true"
-     width="128px"
-     height="128px"
-     showguides="true"
-     inkscape:guide-bbox="true"
-     inkscape:window-width="1920"
-     inkscape:window-height="1016"
-     inkscape:window-x="0"
-     inkscape:window-y="27"
-     inkscape:window-maximized="1">
-    <inkscape:grid
-       type="xygrid"
-       id="grid7947" />
-  </sodipodi:namedview>
-  <metadata
-     id="metadata6848">
-    <rdf:RDF>
-      <cc:Work
-         rdf:about="">
-        <dc:format>image/svg+xml</dc:format>
-        <dc:type
-           rdf:resource="http://purl.org/dc/dcmitype/StillImage" />
-        <dc:title />
-        <dc:date />
-        <dc:creator>
-          <cc:Agent>
-            <dc:title />
-          </cc:Agent>
-        </dc:creator>
-        <dc:rights>
-          <cc:Agent>
-            <dc:title />
-          </cc:Agent>
-        </dc:rights>
-        <dc:publisher>
-          <cc:Agent>
-            <dc:title />
-          </cc:Agent>
-        </dc:publisher>
-        <dc:identifier />
-        <dc:source />
-        <dc:relation />
-        <dc:language />
-        <dc:subject>
-          <rdf:Bag />
-        </dc:subject>
-        <dc:coverage />
-        <dc:description />
-        <dc:contributor>
-          <cc:Agent>
-            <dc:title />
-          </cc:Agent>
-        </dc:contributor>
-        <cc:license
-           rdf:resource="" />
-      </cc:Work>
-      <cc:Work
-         rdf:about="">
-        <dc:format>image/svg+xml</dc:format>
-        <dc:type
-           rdf:resource="http://purl.org/dc/dcmitype/StillImage" />
-      </cc:Work>
-    </rdf:RDF>
-  </metadata>
-  <g
-     id="layer1"
-     inkscape:label="Layer 1"
-     inkscape:groupmode="layer">
-    <path
-       sodipodi:nodetypes="ccccc"
-       id="path6976"
-       d="M 20.88413,30.82696 L 53.816977,55.527708 L 107.33282,39.060543 L 70.587303,17.177763 L 20.88413,30.82696 z"
-       style="fill:#729fcf;fill-opacity:1;fill-rule:evenodd;stroke:#ffffff;stroke-width:2.12364459;stroke-linecap:butt;stroke-linejoin:round;stroke-miterlimit:4;stroke-dasharray:none;stroke-opacity:1;display:inline" />
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-    <path
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-  </g>
-</svg>

demos/gtk-demo/gtkfishbowl.c

@@ -456,33 +456,43 @@ gtk_fishbowl_do_update (GtkFishbowl *fishbowl)
 {
   GtkFishbowlPrivate *priv = gtk_fishbowl_get_instance_private (fishbowl);
   GdkFrameClock *frame_clock;
-  GdkFrameTimings *end;
-  gint64 end_counter;
-  double fps, expected_fps;
+  GdkFrameTimings *start, *end;
+  gint64 start_counter, end_counter;
+  gint64 n_frames, expected_frames;
+  gint64 start_timestamp, end_timestamp;
   gint64 interval;
 
   frame_clock = gtk_widget_get_frame_clock (GTK_WIDGET (fishbowl));
   if (frame_clock == NULL)
     return;
 
-  fps = gdk_frame_clock_get_fps (frame_clock);
-  if (fps <= 0.0)
+  start_counter = gdk_frame_clock_get_history_start (frame_clock);
+  end_counter = gdk_frame_clock_get_frame_counter (frame_clock);
+  start = gdk_frame_clock_get_timings (frame_clock, start_counter);
+  for (end = gdk_frame_clock_get_timings (frame_clock, end_counter);
+       end_counter > start_counter && end != NULL && !gdk_frame_timings_get_complete (end);
+       end = gdk_frame_clock_get_timings (frame_clock, end_counter))
+    end_counter--;
+  if (end_counter - start_counter < 4)
     return;
 
-  priv->framerate = fps;
+  start_timestamp = gdk_frame_timings_get_presentation_time (start);
+  end_timestamp = gdk_frame_timings_get_presentation_time (end);
+  if (start_timestamp == 0 || end_timestamp == 0)
+    {
+      start_timestamp = gdk_frame_timings_get_frame_time (start);
+      end_timestamp = gdk_frame_timings_get_frame_time (end);
+    }
+
+  n_frames = end_counter - start_counter;
+  priv->framerate = ((double) n_frames) * G_USEC_PER_SEC / (end_timestamp - start_timestamp);
+  priv->framerate = ((int)(priv->framerate * 100))/100.0;
+
   g_object_notify_by_pspec (G_OBJECT (fishbowl), props[PROP_FRAMERATE]);
 
   if (!priv->benchmark)
     return;
 
-  end_counter = gdk_frame_clock_get_frame_counter (frame_clock);
-  for (end = gdk_frame_clock_get_timings (frame_clock, end_counter);
-       end != NULL && !gdk_frame_timings_get_complete (end);
-       end = gdk_frame_clock_get_timings (frame_clock, end_counter))
-    end_counter--;
-  if (end == NULL)
-    return;
-
   interval = gdk_frame_timings_get_refresh_interval (end);
   if (interval == 0)
     {
@@ -490,16 +500,16 @@ gtk_fishbowl_do_update (GtkFishbowl *fishbowl)
       if (interval == 0)
         return;
     }
-  expected_fps = (double) G_USEC_PER_SEC / interval;
+  expected_frames = round ((double) (end_timestamp - start_timestamp) / interval);
 
-  if (fps > (expected_fps - 1))
+  if (n_frames >= expected_frames)
     {
       if (priv->last_benchmark_change > 0)
         priv->last_benchmark_change *= 2;
       else
         priv->last_benchmark_change = 1;
     }
-  else if (0.95 * fps < expected_fps)
+  else if (n_frames + 1 < expected_frames)
     {
       if (priv->last_benchmark_change < 0)
         priv->last_benchmark_change--;

demos/gtk-demo/gtkfishbowl.h

@@ -55,7 +55,7 @@ void       gtk_fishbowl_set_animating     (GtkFishbowl       *fishbowl,
                                            gboolean           animating);
 gboolean   gtk_fishbowl_get_benchmark     (GtkFishbowl       *fishbowl);
 void       gtk_fishbowl_set_benchmark     (GtkFishbowl       *fishbowl,
-                                           gboolean           benchmark);
+                                           gboolean           animating);
 double     gtk_fishbowl_get_framerate     (GtkFishbowl       *fishbowl);
 gint64     gtk_fishbowl_get_update_delay  (GtkFishbowl       *fishbowl);
 void       gtk_fishbowl_set_update_delay  (GtkFishbowl       *fishbowl,

demos/gtk-demo/gtkshaderbin.c

@@ -0,0 +1,264 @@
+#include "gtkshaderbin.h"
+
+typedef struct {
+  GskGLShader *shader;
+  GtkStateFlags state;
+  GtkStateFlags state_mask;
+  float extra_border;
+  gboolean compiled;
+  gboolean compiled_ok;
+} ShaderInfo;
+
+struct _GtkShaderBin
+{
+  GtkWidget parent_instance;
+  GtkWidget *child;
+  ShaderInfo *active_shader;
+  GPtrArray *shaders;
+  guint tick_id;
+  float time;
+  float mouse_x, mouse_y;
+  gint64 first_frame_time;
+};
+
+struct _GtkShaderBinClass
+{
+  GtkWidgetClass parent_class;
+};
+
+G_DEFINE_TYPE (GtkShaderBin, gtk_shader_bin, GTK_TYPE_WIDGET)
+
+static void
+shader_info_free (ShaderInfo *info)
+{
+  g_object_unref (info->shader);
+  g_free (info);
+}
+
+static void
+gtk_shader_bin_finalize (GObject *object)
+{
+  GtkShaderBin *self = GTK_SHADER_BIN (object);
+
+  g_ptr_array_free (self->shaders, TRUE);
+
+  G_OBJECT_CLASS (gtk_shader_bin_parent_class)->finalize (object);
+}
+
+static void
+gtk_shader_bin_dispose (GObject *object)
+{
+  GtkShaderBin *self = GTK_SHADER_BIN (object);
+
+  g_clear_pointer (&self->child, gtk_widget_unparent);
+
+  G_OBJECT_CLASS (gtk_shader_bin_parent_class)->dispose (object);
+}
+
+static gboolean
+gtk_shader_bin_tick (GtkWidget     *widget,
+                     GdkFrameClock *frame_clock,
+                     gpointer       unused)
+{
+  GtkShaderBin *self = GTK_SHADER_BIN (widget);
+  gint64 frame_time;
+
+  frame_time = gdk_frame_clock_get_frame_time (frame_clock);
+  if (self->first_frame_time == 0)
+    self->first_frame_time = frame_time;
+  self->time = (frame_time - self->first_frame_time) / (float)G_USEC_PER_SEC;
+
+  gtk_widget_queue_draw (widget);
+
+  return G_SOURCE_CONTINUE;
+}
+
+static void
+motion_cb (GtkEventControllerMotion *controller,
+           double                    x,
+           double                    y,
+           GtkShaderBin             *self)
+{
+  self->mouse_x = x;
+  self->mouse_y = y;
+}
+
+static void
+gtk_shader_bin_init (GtkShaderBin *self)
+{
+  GtkEventController *controller;
+  self->shaders = g_ptr_array_new_with_free_func ((GDestroyNotify)shader_info_free);
+
+  controller = gtk_event_controller_motion_new ();
+  g_signal_connect (controller, "motion", G_CALLBACK (motion_cb), self);
+  gtk_widget_add_controller (GTK_WIDGET (self), controller);
+}
+
+void
+gtk_shader_bin_update_active_shader (GtkShaderBin *self)
+{
+  GtkStateFlags new_state = gtk_widget_get_state_flags (GTK_WIDGET (self));
+  ShaderInfo *new_shader = NULL;
+
+  for (int i = 0; i < self->shaders->len; i++)
+    {
+      ShaderInfo *info = g_ptr_array_index (self->shaders, i);
+
+      if ((info->state_mask & new_state) == info->state)
+        {
+          new_shader = info;
+          break;
+        }
+    }
+
+  if (self->active_shader == new_shader)
+    return;
+
+  self->active_shader = new_shader;
+  self->first_frame_time = 0;
+
+  if (self->active_shader)
+    {
+      if (self->tick_id == 0)
+        self->tick_id = gtk_widget_add_tick_callback (GTK_WIDGET (self),
+                                                      gtk_shader_bin_tick,
+                                                      NULL, NULL);
+    }
+  else
+    {
+      if (self->tick_id != 0)
+        {
+          gtk_widget_remove_tick_callback (GTK_WIDGET (self), self->tick_id);
+          self->tick_id = 0;
+        }
+    }
+
+  gtk_widget_queue_draw (GTK_WIDGET (self));
+}
+
+static void
+gtk_shader_bin_state_flags_changed (GtkWidget        *widget,
+                                    GtkStateFlags     previous_state_flags)
+{
+  GtkShaderBin *self = GTK_SHADER_BIN (widget);
+
+  gtk_shader_bin_update_active_shader (self);
+}
+
+void
+gtk_shader_bin_add_shader (GtkShaderBin *self,
+                           GskGLShader  *shader,
+                           GtkStateFlags state,
+                           GtkStateFlags state_mask,
+                           float         extra_border)
+{
+  ShaderInfo *info = g_new0 (ShaderInfo, 1);
+  info->shader = g_object_ref (shader);
+  info->state = state;
+  info->state_mask = state_mask;
+  info->extra_border = extra_border;
+
+  g_ptr_array_add (self->shaders, info);
+
+  gtk_shader_bin_update_active_shader (self);
+}
+
+void
+gtk_shader_bin_set_child (GtkShaderBin *self,
+                          GtkWidget    *child)
+{
+
+  if (self->child == child)
+    return;
+
+  g_clear_pointer (&self->child, gtk_widget_unparent);
+
+  if (child)
+    {
+      self->child = child;
+      gtk_widget_set_parent (child, GTK_WIDGET (self));
+    }
+}
+
+GtkWidget *
+gtk_shader_bin_get_child   (GtkShaderBin *self)
+{
+  return self->child;
+}
+
+static void
+gtk_shader_bin_snapshot (GtkWidget   *widget,
+                         GtkSnapshot *snapshot)
+{
+  GtkShaderBin *self = GTK_SHADER_BIN (widget);
+  int width, height;
+
+  width = gtk_widget_get_width (widget);
+  height = gtk_widget_get_height (widget);
+
+  if (self->active_shader)
+    {
+      if (!self->active_shader->compiled)
+        {
+          GtkNative *native = gtk_widget_get_native (widget);
+          GskRenderer *renderer = gtk_native_get_renderer (native);
+          GError *error = NULL;
+
+          self->active_shader->compiled = TRUE;
+          self->active_shader->compiled_ok =
+            gsk_gl_shader_compile (self->active_shader->shader,
+                                   renderer, &error);
+          if (!self->active_shader->compiled_ok)
+            {
+              g_warning ("GtkShaderBin failed to compile shader: %s", error->message);
+              g_error_free (error);
+            }
+        }
+
+      if (self->active_shader->compiled_ok)
+        {
+          float border = self->active_shader->extra_border;
+          graphene_vec2_t mouse;
+          graphene_vec2_init (&mouse, self->mouse_x + border, self->mouse_y + border);
+          gtk_snapshot_push_gl_shader (snapshot, self->active_shader->shader,
+                                       &GRAPHENE_RECT_INIT(-border, -border, width+2*border, height+2*border),
+                                       gsk_gl_shader_format_args (self->active_shader->shader,
+                                                                  "u_time", self->time,
+                                                                  "u_mouse", &mouse,
+                                                                  NULL));
+          gtk_widget_snapshot_child (widget, self->child, snapshot);
+          gtk_snapshot_gl_shader_pop_texture (snapshot);
+          gtk_snapshot_pop (snapshot);
+
+          return;
+        }
+    }
+
+  /* Non-shader fallback */
+  gtk_widget_snapshot_child (widget, self->child, snapshot);
+}
+
+static void
+gtk_shader_bin_class_init (GtkShaderBinClass *class)
+{
+  GtkWidgetClass *widget_class = GTK_WIDGET_CLASS (class);
+  GObjectClass *object_class = G_OBJECT_CLASS (class);
+
+  object_class->finalize = gtk_shader_bin_finalize;
+  object_class->dispose = gtk_shader_bin_dispose;
+
+  gtk_widget_class_set_layout_manager_type (widget_class, GTK_TYPE_BIN_LAYOUT);
+
+  widget_class->snapshot = gtk_shader_bin_snapshot;
+  widget_class->state_flags_changed = gtk_shader_bin_state_flags_changed;
+}
+
+GtkWidget *
+gtk_shader_bin_new (void)
+{
+  GtkShaderBin *self;
+
+  self = g_object_new (GTK_TYPE_SHADER_BIN, NULL);
+
+  return GTK_WIDGET (self);
+}

demos/gtk-demo/gtkshaderbin.h

@@ -0,0 +1,20 @@
+#pragma once
+
+#include <gtk/gtk.h>
+
+G_BEGIN_DECLS
+
+#define GTK_TYPE_SHADER_BIN      (gtk_shader_bin_get_type ())
+G_DECLARE_FINAL_TYPE (GtkShaderBin, gtk_shader_bin, GTK, SHADER_BIN, GtkWidget)
+
+GtkWidget  *gtk_shader_bin_new        (void);
+void        gtk_shader_bin_add_shader (GtkShaderBin *self,
+                                       GskGLShader  *shader,
+                                       GtkStateFlags state,
+                                       GtkStateFlags state_mask,
+                                       float         extra_border);
+void       gtk_shader_bin_set_child   (GtkShaderBin *self,
+                                       GtkWidget    *child);
+GtkWidget *gtk_shader_bin_get_child   (GtkShaderBin *self);
+
+G_END_DECLS

demos/gtk-demo/gtkshaderstack.c

@@ -0,0 +1,361 @@
+#include "gtkshaderstack.h"
+
+struct _GtkShaderStack
+{
+  GtkWidget parent_instance;
+
+  GskGLShader *shader;
+  GPtrArray *children;
+  int current;
+  int next;
+  gboolean backwards;
+
+  guint tick_id;
+  float time;
+  float duration;
+  gint64 start_time;
+};
+
+struct _GtkShaderStackClass
+{
+  GtkWidgetClass parent_class;
+};
+
+
+enum {
+  PROP_DURATION = 1,
+  NUM_PROPERTIES
+};
+
+static GParamSpec *properties[NUM_PROPERTIES] = { NULL };
+
+G_DEFINE_TYPE (GtkShaderStack, gtk_shader_stack, GTK_TYPE_WIDGET)
+
+static void
+gtk_shader_stack_finalize (GObject *object)
+{
+  GtkShaderStack *self = GTK_SHADER_STACK (object);
+
+  g_object_unref (self->shader);
+
+  G_OBJECT_CLASS (gtk_shader_stack_parent_class)->finalize (object);
+}
+
+static void
+update_child_visible (GtkShaderStack *self)
+{
+  int i;
+
+  for (i = 0; i < self->children->len; i++)
+    {
+      GtkWidget *child = g_ptr_array_index (self->children, i);
+
+      gtk_widget_set_child_visible (child,
+                                    i == self->current || i == self->next);
+    }
+}
+
+static gboolean
+transition_cb (GtkWidget     *widget,
+               GdkFrameClock *clock,
+               gpointer       unused)
+{
+  GtkShaderStack *self = GTK_SHADER_STACK (widget);
+  gint64 frame_time;
+
+  frame_time = gdk_frame_clock_get_frame_time (clock);
+
+  if (self->start_time == 0)
+    self->start_time = frame_time;
+
+  self->time = (frame_time - self->start_time) / (float)G_USEC_PER_SEC;
+
+  gtk_widget_queue_draw (widget);
+
+  if (self->time >= self->duration)
+    {
+      self->current = self->next;
+      self->next = -1;
+
+      update_child_visible (self);
+
+      return G_SOURCE_REMOVE;
+    }
+  else
+    return G_SOURCE_CONTINUE;
+}
+
+static void
+start_transition (GtkShaderStack *self)
+{
+  self->start_time = 0;
+  self->tick_id = gtk_widget_add_tick_callback (GTK_WIDGET (self),
+                                                transition_cb,
+                                                NULL, NULL);
+}
+
+static void
+stop_transition (GtkShaderStack *self)
+{
+  if (self->tick_id != 0)
+    {
+      gtk_widget_remove_tick_callback (GTK_WIDGET (self), self->tick_id);
+      self->tick_id = 0;
+    }
+
+  if (self->next != -1)
+    self->current = self->next;
+  self->next = -1;
+
+  update_child_visible (self);
+}
+
+static void
+gtk_shader_stack_dispose (GObject *object)
+{
+  GtkShaderStack *self = GTK_SHADER_STACK (object);
+
+  stop_transition (self);
+
+  g_clear_pointer (&self->children, g_ptr_array_unref);
+
+  G_OBJECT_CLASS (gtk_shader_stack_parent_class)->dispose (object);
+}
+
+void
+gtk_shader_stack_transition (GtkShaderStack *self,
+                             gboolean forward)
+{
+  stop_transition (self);
+
+  self->backwards = !forward;
+  if (self->backwards)
+    self->next = (self->current + self->children->len - 1) % self->children->len;
+  else
+    self->next = (self->current + 1) % self->children->len;
+
+  update_child_visible (self);
+
+  start_transition (self);
+}
+
+static void
+gtk_shader_stack_init (GtkShaderStack *self)
+{
+  self->children = g_ptr_array_new_with_free_func ((GDestroyNotify)gtk_widget_unparent);
+  self->current = -1;
+  self->next = -1;
+  self->backwards = FALSE;
+  self->duration = 1.0;
+}
+
+static void
+gtk_shader_stack_measure (GtkWidget      *widget,
+                          GtkOrientation  orientation,
+                          int             for_size,
+                          int            *minimum,
+                          int            *natural,
+                          int            *minimum_baseline,
+                          int            *natural_baseline)
+{
+  GtkShaderStack *self = GTK_SHADER_STACK (widget);
+  int i;
+
+  *minimum = 0;
+  *natural = 0;
+
+  for (i = 0; i < self->children->len; i++)
+    {
+      GtkWidget *child = g_ptr_array_index (self->children, i);
+      int child_min, child_nat;
+
+      if (gtk_widget_get_visible (child))
+        {
+          gtk_widget_measure (child, orientation, for_size, &child_min, &child_nat, NULL, NULL);
+
+          *minimum = MAX (*minimum, child_min);
+          *natural = MAX (*natural, child_nat);
+        }
+    }
+}
+
+static void
+gtk_shader_stack_size_allocate (GtkWidget *widget,
+                                int        width,
+                                int        height,
+                                int        baseline)
+{
+  GtkShaderStack *self = GTK_SHADER_STACK (widget);
+  GtkAllocation child_allocation;
+  GtkWidget *child;
+  int i;
+
+  child_allocation.x = 0;
+  child_allocation.y = 0;
+  child_allocation.width = width;
+  child_allocation.height = height;
+
+  for (i = 0; i < self->children->len; i++)
+    {
+      child = g_ptr_array_index (self->children, i);
+      if (gtk_widget_get_visible (child))
+        gtk_widget_size_allocate (child, &child_allocation, -1);
+    }
+}
+
+static void
+gtk_shader_stack_snapshot (GtkWidget   *widget,
+                           GtkSnapshot *snapshot)
+{
+  GtkShaderStack *self = GTK_SHADER_STACK (widget);
+  int width, height;
+  GtkWidget *current, *next;
+
+  width = gtk_widget_get_width (widget);
+  height = gtk_widget_get_height (widget);
+
+  current = g_ptr_array_index (self->children, self->current);
+
+  if (self->next == -1)
+    {
+      gtk_widget_snapshot_child (widget, current, snapshot);
+    }
+  else
+    {
+      GtkNative *native = gtk_widget_get_native (widget);
+      GskRenderer *renderer = gtk_native_get_renderer (native);
+      float progress;
+
+      next = g_ptr_array_index (self->children, self->next);
+
+      progress = self->time / self->duration;
+
+      if (self->backwards)
+        {
+          GtkWidget *tmp = next;
+          next = current;
+          current = tmp;
+          progress = 1. - progress;
+        }
+
+      if (gsk_gl_shader_compile (self->shader, renderer, NULL))
+        {
+          gtk_snapshot_push_gl_shader (snapshot,
+                                       self->shader,
+                                       &GRAPHENE_RECT_INIT(0, 0, width, height),
+                                       gsk_gl_shader_format_args (self->shader,
+                                                                  "progress", progress,
+                                                                  NULL));
+
+          gtk_widget_snapshot_child (widget, current, snapshot);
+          gtk_snapshot_gl_shader_pop_texture (snapshot); /* current child */
+          gtk_widget_snapshot_child (widget, next, snapshot);
+          gtk_snapshot_gl_shader_pop_texture (snapshot); /* next child */
+          gtk_snapshot_pop (snapshot);
+        }
+      else
+        {
+          /* Non-shader fallback */
+          gtk_widget_snapshot_child (widget, current, snapshot);
+        }
+    }
+}
+
+static void
+gtk_shader_stack_get_property (GObject      *object,
+                               guint         prop_id,
+                               GValue       *value,
+                               GParamSpec   *pspec)
+{
+  GtkShaderStack *self = GTK_SHADER_STACK (object);
+
+  switch (prop_id)
+    {
+    case PROP_DURATION:
+      g_value_set_float (value, self->duration);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+      break;
+    }
+}
+
+static void
+gtk_shader_stack_set_property (GObject      *object,
+                               guint         prop_id,
+                               const GValue *value,
+                               GParamSpec   *pspec)
+{
+  GtkShaderStack *self = GTK_SHADER_STACK (object);
+
+  switch (prop_id)
+    {
+    case PROP_DURATION:
+      self->duration = g_value_get_float (value);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+      break;
+    }
+}
+
+static void
+gtk_shader_stack_class_init (GtkShaderStackClass *class)
+{
+  GtkWidgetClass *widget_class = GTK_WIDGET_CLASS (class);
+  GObjectClass *object_class = G_OBJECT_CLASS (class);
+
+  object_class->finalize = gtk_shader_stack_finalize;
+  object_class->dispose = gtk_shader_stack_dispose;
+  object_class->get_property = gtk_shader_stack_get_property;
+  object_class->set_property = gtk_shader_stack_set_property;
+
+  widget_class->snapshot = gtk_shader_stack_snapshot;
+  widget_class->measure = gtk_shader_stack_measure;
+  widget_class->size_allocate = gtk_shader_stack_size_allocate;
+
+  properties[PROP_DURATION] =
+      g_param_spec_float ("duration", "Duration", "Duration",
+                          0.1, 3.0, 1.0,
+                          G_PARAM_READWRITE);
+
+  g_object_class_install_properties (object_class, NUM_PROPERTIES, properties);
+}
+
+GtkWidget *
+gtk_shader_stack_new (void)
+{
+  return g_object_new (GTK_TYPE_SHADER_STACK, NULL);
+}
+
+void
+gtk_shader_stack_set_shader (GtkShaderStack *self,
+                             GskGLShader    *shader)
+{
+  g_set_object (&self->shader, shader);
+}
+
+void
+gtk_shader_stack_add_child (GtkShaderStack *self,
+                            GtkWidget      *child)
+{
+  g_ptr_array_add (self->children, child);
+  gtk_widget_set_parent (child, GTK_WIDGET (self));
+  gtk_widget_queue_resize (GTK_WIDGET (self));
+
+  if (self->current == -1)
+    self->current = 0;
+  else
+    gtk_widget_set_child_visible (child, FALSE);
+}
+
+void
+gtk_shader_stack_set_active (GtkShaderStack *self,
+                             int             index)
+{
+  stop_transition (self);
+  self->current = MIN (index, self->children->len);
+  update_child_visible (self);
+}

demos/gtk-demo/gtkshaderstack.h

@@ -0,0 +1,20 @@
+#pragma once
+
+#include <gtk/gtk.h>
+
+G_BEGIN_DECLS
+
+#define GTK_TYPE_SHADER_STACK     (gtk_shader_stack_get_type ())
+G_DECLARE_FINAL_TYPE (GtkShaderStack, gtk_shader_stack, GTK, SHADER_STACK, GtkWidget)
+
+GtkWidget * gtk_shader_stack_new          (void);
+void        gtk_shader_stack_set_shader   (GtkShaderStack *self,
+                                           GskGLShader    *shader);
+void        gtk_shader_stack_add_child    (GtkShaderStack *self,
+                                           GtkWidget      *child);
+void        gtk_shader_stack_transition   (GtkShaderStack *self,
+                                           gboolean        forward);
+void        gtk_shader_stack_set_active   (GtkShaderStack *self,
+                                           int             index);
+
+G_END_DECLS

demos/gtk-demo/hsla.h

@@ -1,7 +1,5 @@
 #pragma once
 
-#include <gdk/gdk.h>
-
 typedef struct _GdkHSLA GdkHSLA;
 
 struct _GdkHSLA {

demos/gtk-demo/iconscroll.c

@@ -13,7 +13,7 @@ static GtkWidget *window = NULL;
 static GtkWidget *scrolledwindow;
 static int selected;
 
-#define N_WIDGET_TYPES 9
+#define N_WIDGET_TYPES 8
 
 
 static int hincrement = 5;
@@ -73,77 +73,30 @@ populate_icons (void)
   gtk_scrolled_window_set_child (GTK_SCROLLED_WINDOW (scrolledwindow), grid);
 }
 
+static char *content;
+static gsize content_len;
+
 extern void fontify (const char *format, GtkTextBuffer *buffer);
 
-enum {
-  PLAIN_TEXT,
-  HIGHLIGHTED_TEXT,
-  UNDERLINED_TEXT,
-};
-
 static void
-underlinify (GtkTextBuffer *buffer)
-{
-  GtkTextTagTable *tags;
-  GtkTextTag *tag[3];
-  GtkTextIter start, end;
-
-  tags = gtk_text_buffer_get_tag_table (buffer);
-  tag[0] = gtk_text_tag_new ("error");
-  tag[1] = gtk_text_tag_new ("strikeout");
-  tag[2] = gtk_text_tag_new ("double");
-  g_object_set (tag[0], "underline", PANGO_UNDERLINE_ERROR, NULL);
-  g_object_set (tag[1], "strikethrough", TRUE, NULL);
-  g_object_set (tag[2],
-                "underline", PANGO_UNDERLINE_DOUBLE,
-                "underline-rgba", &(GdkRGBA){0., 1., 1., 1. },
-                NULL);
-  gtk_text_tag_table_add (tags, tag[0]);
-  gtk_text_tag_table_add (tags, tag[1]);
-  gtk_text_tag_table_add (tags, tag[2]);
-
-  gtk_text_buffer_get_start_iter (buffer, &end);
-
-  while (TRUE)
-    {
-      gtk_text_iter_forward_word_end (&end);
-      start = end;
-      gtk_text_iter_backward_word_start (&start);
-      gtk_text_buffer_apply_tag (buffer, tag[g_random_int_range (0, 3)], &start, &end);
-      if (!gtk_text_iter_forward_word_ends (&end, 3))
-        break;
-    }
-}
-
-static void
-populate_text (const char *resource, int kind)
+populate_text (gboolean highlight)
 {
   GtkWidget *textview;
   GtkTextBuffer *buffer;
-  char *content;
-  gsize content_len;
-  GBytes *bytes;
 
-  bytes = g_resources_lookup_data (resource, 0, NULL);
-  content = g_bytes_unref_to_data (bytes, &content_len);
+  if (!content)
+    {
+      GBytes *bytes;
+
+      bytes = g_resources_lookup_data ("/sources/font_features.c", 0, NULL);
+      content = g_bytes_unref_to_data (bytes, &content_len);
+    }
 
   buffer = gtk_text_buffer_new (NULL);
   gtk_text_buffer_set_text (buffer, content, (int)content_len);
 
-  switch (kind)
-    {
-    case HIGHLIGHTED_TEXT:
-      fontify ("c", buffer);
-      break;
-
-    case UNDERLINED_TEXT:
-      underlinify (buffer);
-      break;
-
-    case PLAIN_TEXT:
-    default:
-      break;
-    }
+  if (highlight)
+    fontify ("c", buffer);
 
   textview = gtk_text_view_new ();
   gtk_text_view_set_buffer (GTK_TEXT_VIEW (textview), buffer);
@@ -202,6 +155,14 @@ populate_image (void)
 {
   GtkWidget *image;
 
+  if (!content)
+    {
+      GBytes *bytes;
+
+      bytes = g_resources_lookup_data ("/sources/font_features.c", 0, NULL);
+      content = g_bytes_unref_to_data (bytes, &content_len);
+    }
+
   image = gtk_picture_new_for_resource ("/sliding_puzzle/portland-rose.jpg");
   gtk_picture_set_can_shrink (GTK_PICTURE (image), FALSE);
 
@@ -294,40 +255,35 @@ set_widget_type (int type)
 
     case 1:
       gtk_window_set_title (GTK_WINDOW (window), "Scrolling plain text");
-      populate_text ("/sources/font_features.c", PLAIN_TEXT);
+      populate_text (FALSE);
       break;
 
     case 2:
-      gtk_window_set_title (GTK_WINDOW (window), "Scrolling colored text");
-      populate_text ("/sources/font_features.c", HIGHLIGHTED_TEXT);
+      gtk_window_set_title (GTK_WINDOW (window), "Scrolling complex text");
+      populate_text (TRUE);
       break;
 
     case 3:
-      gtk_window_set_title (GTK_WINDOW (window), "Scrolling text with underlines");
-      populate_text ("/org/gtk/Demo4/Moby-Dick.txt", UNDERLINED_TEXT);
-      break;
-
-    case 4:
       gtk_window_set_title (GTK_WINDOW (window), "Scrolling text with Emoji");
       populate_emoji_text ();
       break;
 
-    case 5:
+    case 4:
       gtk_window_set_title (GTK_WINDOW (window), "Scrolling a big image");
       populate_image ();
       break;
 
-    case 6:
+    case 5:
       gtk_window_set_title (GTK_WINDOW (window), "Scrolling a list");
       populate_list ();
       break;
 
-    case 7:
+    case 6:
       gtk_window_set_title (GTK_WINDOW (window), "Scrolling a columned list");
       populate_list2 ();
       break;
 
-    case 8:
+    case 7:
       gtk_window_set_title (GTK_WINDOW (window), "Scrolling a grid");
       populate_grid ();
       break;

demos/gtk-demo/iconscroll.ui

@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <interface>
   <object class="GtkWindow" id="window">
-    <property name="resizable">1</property>
+    <property name="resizable">0</property>
     <property name="default-width">500</property>
     <property name="default-height">500</property>
     <child type="titlebar">

demos/gtk-demo/image_scaling.c

@@ -14,103 +14,6 @@
 #include <gtk/gtk.h>
 #include "demo3widget.h"
 
-static GtkWidget *window = NULL;
-static GCancellable *cancellable = NULL;
-
-static void
-load_texture (GTask        *task,
-              gpointer      source_object,
-              gpointer      task_data,
-              GCancellable *cable)
-{
-  GFile *file = task_data;
-  GdkTexture *texture;
-  GError *error = NULL;
-
-  texture = gdk_texture_new_from_file (file, &error);
-
-  if (texture)
-    g_task_return_pointer (task, texture, g_object_unref);
-  else
-    g_task_return_error (task, error);
-}
-
-static void
-set_wait_cursor (GtkWidget *widget)
-{
-  gtk_widget_set_cursor_from_name (GTK_WIDGET (gtk_widget_get_root (widget)), "wait");
-}
-
-static void
-unset_wait_cursor (GtkWidget *widget)
-{
-  gtk_widget_set_cursor (GTK_WIDGET (gtk_widget_get_root (widget)), NULL);
-}
-
-static void
-texture_loaded (GObject      *source,
-                GAsyncResult *result,
-                gpointer      data)
-{
-  GdkTexture *texture;
-  GError *error = NULL;
-
-  texture = g_task_propagate_pointer (G_TASK (result), &error);
-
-  if (!texture)
-    {
-      g_print ("%s\n", error->message);
-      g_error_free (error);
-      return;
-    }
-
-  if (!window)
-    {
-      g_object_unref (texture);
-      return;
-    }
-
-  unset_wait_cursor (GTK_WIDGET (data));
-
-  g_object_set (G_OBJECT (data), "texture", texture, NULL);
-}
-
-static void
-open_file_async (GFile     *file,
-                 GtkWidget *demo)
-{
-  GTask *task;
-
-  set_wait_cursor (demo);
-
-  task = g_task_new (demo, cancellable, texture_loaded, demo);
-  g_task_set_task_data (task, g_object_ref (file), g_object_unref);
-  g_task_run_in_thread (task, load_texture);
-  g_object_unref (task);
-}
-
-static void
-open_portland_rose (GtkWidget *button,
-                    GtkWidget *demo)
-{
-  GFile *file;
-
-  file = g_file_new_for_uri ("resource:///transparent/portland-rose.jpg");
-  open_file_async (file, demo);
-  g_object_unref (file);
-}
-
-static void
-open_large_image (GtkWidget *button,
-                  GtkWidget *demo)
-{
-  GFile *file;
-
-  file = g_file_new_for_uri ("resource:///org/gtk/Demo4/large-image.png");
-  open_file_async (file, demo);
-  g_object_unref (file);
-}
-
 static void
 file_opened (GObject      *source,
              GAsyncResult *result,
@@ -118,6 +21,7 @@ file_opened (GObject      *source,
 {
   GFile *file;
   GError *error = NULL;
+  GdkTexture *texture;
 
   file = gtk_file_dialog_open_finish (GTK_FILE_DIALOG (source), result, &error);
 
@@ -128,9 +32,17 @@ file_opened (GObject      *source,
       return;
     }
 
-  open_file_async (file, data);
-
+  texture = gdk_texture_new_from_file (file, &error);
   g_object_unref (file);
+  if (!texture)
+    {
+      g_print ("%s\n", error->message);
+      g_error_free (error);
+      return;
+    }
+
+  g_object_set (G_OBJECT (data), "texture", texture, NULL);
+  g_object_unref (texture);
 }
 
 static void
@@ -204,26 +116,11 @@ transform_from (GBinding     *binding,
   return TRUE;
 }
 
-static void
-free_cancellable (gpointer data)
-{
-  g_cancellable_cancel (cancellable);
-  g_clear_object (&cancellable);
-}
-
-static gboolean
-cancel_load (GtkWidget *widget,
-             GVariant  *args,
-             gpointer   data)
-{
-  unset_wait_cursor (widget);
-  g_cancellable_cancel (G_CANCELLABLE (data));
-  return TRUE;
-}
-
 GtkWidget *
 do_image_scaling (GtkWidget *do_widget)
 {
+  static GtkWidget *window = NULL;
+
   if (!window)
     {
       GtkWidget *box;
@@ -233,7 +130,6 @@ do_image_scaling (GtkWidget *do_widget)
       GtkWidget *scale;
       GtkWidget *dropdown;
       GtkWidget *button;
-      GtkEventController *controller;
 
       window = gtk_window_new ();
       gtk_window_set_title (GTK_WINDOW (window), "Image Scaling");
@@ -242,20 +138,6 @@ do_image_scaling (GtkWidget *do_widget)
                               gtk_widget_get_display (do_widget));
       g_object_add_weak_pointer (G_OBJECT (window), (gpointer *)&window);
 
-      cancellable = g_cancellable_new ();
-      g_object_set_data_full (G_OBJECT (window), "cancellable",
-                              cancellable, free_cancellable);
-
-      controller = gtk_shortcut_controller_new ();
-      gtk_shortcut_controller_add_shortcut (GTK_SHORTCUT_CONTROLLER (controller),
-                                            gtk_shortcut_new (
-                                                gtk_keyval_trigger_new (GDK_KEY_Escape, 0),
-                                                gtk_callback_action_new (cancel_load, cancellable, NULL)
-                                                ));
-      gtk_shortcut_controller_set_scope (GTK_SHORTCUT_CONTROLLER (controller),
-                                         GTK_SHORTCUT_SCOPE_GLOBAL);
-      gtk_widget_add_controller (window, controller);
-
       box = gtk_box_new (GTK_ORIENTATION_VERTICAL, 0);
       gtk_window_set_child (GTK_WINDOW (window), box);
 
@@ -274,22 +156,6 @@ do_image_scaling (GtkWidget *do_widget)
       g_signal_connect (button, "clicked", G_CALLBACK (open_file), widget);
       gtk_box_append (GTK_BOX (box2), button);
 
-      button = gtk_button_new ();
-      gtk_button_set_child (GTK_BUTTON (button),
-                            gtk_image_new_from_resource ("/org/gtk/Demo4/portland-rose-thumbnail.png"));
-      gtk_widget_add_css_class (button, "image-button");
-      gtk_widget_set_tooltip_text (button, "Portland Rose");
-      g_signal_connect (button, "clicked", G_CALLBACK (open_portland_rose), widget);
-      gtk_box_append (GTK_BOX (box2), button);
-
-      button = gtk_button_new ();
-      gtk_button_set_child (GTK_BUTTON (button),
-                            gtk_image_new_from_resource ("/org/gtk/Demo4/large-image-thumbnail.png"));
-      gtk_widget_add_css_class (button, "image-button");
-      gtk_widget_set_tooltip_text (button, "Large image");
-      g_signal_connect (button, "clicked", G_CALLBACK (open_large_image), widget);
-      gtk_box_append (GTK_BOX (box2), button);
-
       button = gtk_button_new_from_icon_name ("object-rotate-right-symbolic");
       gtk_widget_set_tooltip_text (button, "Rotate");
       g_signal_connect (button, "clicked", G_CALLBACK (rotate), widget);
@@ -325,9 +191,7 @@ do_image_scaling (GtkWidget *do_widget)
   if (!gtk_widget_get_visible (window))
     gtk_widget_set_visible (window, TRUE);
   else
-    {
-      gtk_window_destroy (GTK_WINDOW (window));
-    }
+    gtk_window_destroy (GTK_WINDOW (window));
 
   return window;
 }

demos/gtk-demo/kaleidoscope.glsl

@@ -0,0 +1,41 @@
+uniform float progress;
+uniform sampler2D u_texture1;
+uniform sampler2D u_texture2;
+
+vec4 getFromColor (vec2 uv) {
+  return GskTexture(u_texture1, uv);
+}
+
+vec4 getToColor (vec2 uv) {
+  return GskTexture(u_texture2, uv);
+}
+
+// Source: https://gl-transitions.com/editor/kaleidoscope
+// Author: nwoeanhinnogaehr
+// License: MIT
+
+const float speed = 1.0;
+const float angle = 1.0;
+const float power = 1.5;
+
+vec4 transition(vec2 uv) {
+  vec2 p = uv.xy / vec2(1.0).xy;
+  vec2 q = p;
+  float t = pow(progress, power)*speed;
+  p = p -0.5;
+  for (int i = 0; i < 7; i++) {
+    p = vec2(sin(t)*p.x + cos(t)*p.y, sin(t)*p.y - cos(t)*p.x);
+    t += angle;
+    p = abs(mod(p, 2.0) - 1.0);
+  }
+  abs(mod(p, 1.0));
+  return mix(
+    mix(getFromColor(q), getToColor(q), progress),
+    mix(getFromColor(p), getToColor(p), progress), 1.0 - 2.0*abs(progress - 0.5));
+}
+
+
+void mainImage(out vec4 fragColor, in vec2 fragCoord, in vec2 resolution, in vec2 uv)
+{
+  fragColor = transition(uv);
+}

demos/gtk-demo/language-names.c

@@ -40,7 +40,7 @@ get_win32_all_locales_scripts (LPWSTR locale_w, DWORD flags, LPARAM param)
 {
   wchar_t *langname_w = NULL;
   wchar_t locale_abbrev_w[9];
-  gchar *langname, *locale_abbrev, *locale;
+  gchar *langname, *locale_abbrev, *locale, *p;
   gint i;
   const LCTYPE iso639_lctypes[] = { LOCALE_SISO639LANGNAME, LOCALE_SISO639LANGNAME2 };
   GHashTable *ht_scripts_langs = (GHashTable *) param;
@@ -59,6 +59,7 @@ get_win32_all_locales_scripts (LPWSTR locale_w, DWORD flags, LPARAM param)
   GetLocaleInfoEx (locale_w, LOCALE_SLOCALIZEDDISPLAYNAME, langname_w, langname_size);
   langname = g_utf16_to_utf8 (langname_w, -1, NULL, NULL, NULL);
   locale = g_utf16_to_utf8 (locale_w, -1, NULL, NULL, NULL);
+  p = strchr (locale, '-');
   lang = pango_language_from_string (locale);
   if (g_hash_table_lookup (ht_scripts_langs, lang) == NULL)
     g_hash_table_insert (ht_scripts_langs, lang, langname);

demos/gtk-demo/listview_clocks.c

@@ -355,28 +355,28 @@ create_clocks_model (void)
   g_list_store_append (result, clock);
   g_object_unref (clock);
   /* A bunch of timezones with GTK hackers */
-  clock = gtk_clock_new ("San Francisco", g_time_zone_new_identifier ("America/Los_Angeles"));
+  clock = gtk_clock_new ("San Francisco", g_time_zone_new ("America/Los_Angeles"));
   g_list_store_append (result, clock);
   g_object_unref (clock);
-  clock = gtk_clock_new ("Xalapa", g_time_zone_new_identifier ("America/Mexico_City"));
+  clock = gtk_clock_new ("Xalapa", g_time_zone_new ("America/Mexico_City"));
   g_list_store_append (result, clock);
   g_object_unref (clock);
-  clock = gtk_clock_new ("Boston", g_time_zone_new_identifier ("America/New_York"));
+  clock = gtk_clock_new ("Boston", g_time_zone_new ("America/New_York"));
   g_list_store_append (result, clock);
   g_object_unref (clock);
-  clock = gtk_clock_new ("London", g_time_zone_new_identifier ("Europe/London"));
+  clock = gtk_clock_new ("London", g_time_zone_new ("Europe/London"));
   g_list_store_append (result, clock);
   g_object_unref (clock);
-  clock = gtk_clock_new ("Berlin", g_time_zone_new_identifier ("Europe/Berlin"));
+  clock = gtk_clock_new ("Berlin", g_time_zone_new ("Europe/Berlin"));
   g_list_store_append (result, clock);
   g_object_unref (clock);
-  clock = gtk_clock_new ("Moscow", g_time_zone_new_identifier ("Europe/Moscow"));
+  clock = gtk_clock_new ("Moscow", g_time_zone_new ("Europe/Moscow"));
   g_list_store_append (result, clock);
   g_object_unref (clock);
-  clock = gtk_clock_new ("New Delhi", g_time_zone_new_identifier ("Asia/Kolkata"));
+  clock = gtk_clock_new ("New Delhi", g_time_zone_new ("Asia/Kolkata"));
   g_list_store_append (result, clock);
   g_object_unref (clock);
-  clock = gtk_clock_new ("Shanghai", g_time_zone_new_identifier ("Asia/Shanghai"));
+  clock = gtk_clock_new ("Shanghai", g_time_zone_new ("Asia/Shanghai"));
   g_list_store_append (result, clock);
   g_object_unref (clock);
 

demos/gtk-demo/main.c

@@ -20,7 +20,6 @@
 #include "config.h"
 #include <gtk/gtk.h>
 #include <glib/gstdio.h>
-#include <glib/gi18n.h>
 
 #include "demos.h"
 #include "fontify.h"
@@ -156,6 +155,11 @@ gtk_demo_run (GtkDemo   *self,
   if (result == NULL)
     return FALSE;
 
+  if (GTK_IS_WINDOW (result))
+    {
+      gtk_window_set_transient_for (GTK_WINDOW (result), GTK_WINDOW (window));
+      gtk_window_set_modal (GTK_WINDOW (result), TRUE);
+    }
   return TRUE;
 }
 
@@ -827,6 +831,9 @@ static gboolean
 demo_can_run (GtkWidget  *window,
               const char *name)
 {
+  if (name != NULL && strcmp (name, "gltransition") == 0)
+    return GSK_IS_GL_RENDERER (gtk_native_get_renderer (GTK_NATIVE (window)));
+
   return TRUE;
 }
 
@@ -916,34 +923,6 @@ clear_search (GtkSearchBar *bar)
     }
 }
 
-static void
-search_results_update (GObject    *filter_model,
-                       GParamSpec *pspec,
-                       GtkEntry   *entry)
-{
-  gsize n_items = g_list_model_get_n_items (G_LIST_MODEL (filter_model));
-
-  if (strlen (gtk_editable_get_text (GTK_EDITABLE (entry))) > 0)
-    {
-      char *text;
-
-      if (n_items > 0)
-        text = g_strdup_printf (ngettext ("%ld search result", "%ld search results", (long) n_items), (long) n_items);
-      else
-        text = g_strdup (_("No search results"));
-
-      gtk_accessible_update_property (GTK_ACCESSIBLE (entry),
-                                      GTK_ACCESSIBLE_PROPERTY_DESCRIPTION, text,
-                                      -1);
-
-      g_free (text);
-    }
-  else
-    {
-      gtk_accessible_reset_property (GTK_ACCESSIBLE (entry), GTK_ACCESSIBLE_PROPERTY_DESCRIPTION);
-    }
-}
-
 static void
 activate (GApplication *app)
 {
@@ -991,7 +970,6 @@ activate (GApplication *app)
 
   search_entry = GTK_WIDGET (gtk_builder_get_object (builder, "search-entry"));
   g_signal_connect (search_entry, "search-changed", G_CALLBACK (demo_search_changed_cb), filter);
-  g_signal_connect (filter_model, "notify::n-items", G_CALLBACK (search_results_update), search_entry);
 
   selection = gtk_single_selection_new (G_LIST_MODEL (filter_model));
   g_signal_connect (selection, "notify::selected-item", G_CALLBACK (selection_cb), NULL);
@@ -1060,8 +1038,6 @@ command_line (GApplication            *app,
 
   window = gtk_application_get_windows (GTK_APPLICATION (app))->data;
 
-  gtk_window_set_icon_name (GTK_WINDOW (window), "org.gtk.Demo4");
-
   if (name == NULL)
     goto out;
 

demos/gtk-demo/menus.ui

@@ -2,7 +2,7 @@
 <interface>
   <menu id="menubar">
     <submenu>
-      <attribute name="label" translatable="yes">_File</attribute>
+      <attribute name="label" translatable="yes">_Application</attribute>
       <section>
         <item>
           <attribute name="label" translatable="yes">_New</attribute>
@@ -33,7 +33,7 @@
       </section>
     </submenu>
     <submenu>
-      <attribute name="label" translatable="yes">_Preferences</attribute>
+      <attribute name="label" translatable="yes">_File</attribute>
       <section>
         <item>
           <attribute name="label" translatable="yes">_Prefer Dark Theme</attribute>

demos/gtk-demo/meson.build

@@ -33,6 +33,7 @@ demos = files([
   'gears.c',
   'gestures.c',
   'glarea.c',
+  'gltransition.c',
   'headerbar.c',
   'hypertext.c',
   'iconscroll.c',
@@ -116,7 +117,10 @@ extra_demo_sources = files([
   'gtkfishbowl.c',
   'fontplane.c',
   'gtkgears.c',
+  'gtkshaderbin.c',
   'gtkshadertoy.c',
+  'gtkshaderstack.c',
+  'gskshaderpaintable.c',
   'hsla.c',
   'puzzlepiece.c',
   'bluroverlay.c',

demos/gtk-demo/nodewidget.h

@@ -5,4 +5,4 @@
 #define NODE_TYPE_WIDGET (node_widget_get_type ())
 G_DECLARE_FINAL_TYPE (NodeWidget, node_widget, NODE, WIDGET, GtkWidget)
 
-GtkWidget * node_widget_new       (const char *resource);
+GtkWidget * node_widget_new       (const char *file);

demos/gtk-demo/path_fill.c

@@ -225,8 +225,7 @@ print_ready (GObject      *source,
 
   if (!g_output_stream_close (stream, NULL, &error))
     {
-      if (!g_error_matches (error, GTK_DIALOG_ERROR, GTK_DIALOG_ERROR_DISMISSED))
-        g_print ("Error from close: %s\n", error->message);
+      g_print ("Error from close: %s\n", error->message);
       g_error_free (error);
     }
 

demos/gtk-demo/radial.glsl

@@ -0,0 +1,34 @@
+uniform float progress;
+uniform sampler2D u_texture1;
+uniform sampler2D u_texture2;
+
+vec4 getFromColor (vec2 uv) {
+  return GskTexture(u_texture1, uv);
+}
+
+vec4 getToColor (vec2 uv) {
+  return GskTexture(u_texture2, uv);
+}
+
+// Source: https://gl-transitions.com/editor/Radial
+// License: MIT
+// Author: Xaychru
+
+const float smoothness = 1.0;
+
+const float PI = 3.141592653589;
+
+vec4 transition(vec2 p) {
+  vec2 rp = p*2.-1.;
+  return mix(
+    getToColor(p),
+    getFromColor(p),
+    smoothstep(0., smoothness, atan(rp.y,rp.x) - (progress-.5) * PI * 2.5)
+  );
+}
+
+
+void mainImage(out vec4 fragColor, in vec2 fragCoord, in vec2 resolution, in vec2 uv)
+{
+  fragColor = transition(uv);
+}

demos/gtk-demo/ripple.glsl

@@ -0,0 +1,43 @@
+uniform float u_time;
+uniform vec2 u_mouse;
+uniform sampler2D u_texture1;
+
+#define PI      3.141592654
+
+float decay(float v, float t)
+{
+  return v * (1.0 / (1.0 + t*t));
+}
+
+void mainImage(out vec4 fragColor, in vec2 fragCoord, in vec2 resolution, in vec2 uv)
+{
+  // Temporary to loop time every 1 sec
+  float time = u_time;
+  // we normalize all the effects according to the min height/width
+  float size = min(resolution.x, resolution.y);
+
+  // Animate one wave over size in 0.3 sec
+  float wave_speed = size / 0.3;
+  float wave_length = size / 1.0;
+  float wave_height = size  * 0.1;
+
+  vec2 center = u_mouse;
+  vec2 direction_from_center = fragCoord - center;
+  float distance_from_center = length(direction_from_center);
+
+  /* Normalize direction */
+  direction_from_center = direction_from_center / distance_from_center;
+
+  float propagation_length = time * wave_speed;
+
+  float t = (propagation_length - distance_from_center) / wave_length;
+  float offset_magnitude = 0.0;
+  if (t > 0.0)
+    offset_magnitude = decay(wave_height * sin(t * 2.0 * PI), t);
+
+  vec2 offset = direction_from_center * min(offset_magnitude, distance_from_center);
+  vec2 source = fragCoord - offset;
+
+  vec2 uv2 = source / resolution;
+  fragColor = GskTexture(u_texture1, vec2(uv2.x, 1.0-uv2.y));
+}

demos/gtk-demo/shadertoy.c

@@ -120,7 +120,7 @@ create_shadertoy_window (GtkWidget *do_widget)
   gtk_box_append (GTK_BOX (box), aspect);
 
   shadertoy = new_shadertoy ("/shadertoy/alienplanet.glsl");
-  gtk_aspect_frame_set_child (GTK_ASPECT_FRAME (aspect), gtk_graphics_offload_new (shadertoy));
+  gtk_aspect_frame_set_child (GTK_ASPECT_FRAME (aspect), shadertoy);
 
   sw = gtk_scrolled_window_new ();
   gtk_scrolled_window_set_min_content_height (GTK_SCROLLED_WINDOW (sw), 250);

demos/gtk-demo/suggestionentry.h

@@ -43,7 +43,7 @@ GtkListItemFactory *
                 suggestion_entry_get_factory        (SuggestionEntry     *self);
 
 void            suggestion_entry_set_use_filter     (SuggestionEntry     *self,
-                                                     gboolean             use_filter);
+                                                     gboolean             use_ilter);
 gboolean        suggestion_entry_get_use_filter     (SuggestionEntry     *self);
 
 void            suggestion_entry_set_expression     (SuggestionEntry     *self,

demos/gtk-demo/wind.glsl

@@ -0,0 +1,33 @@
+uniform float progress;
+uniform sampler2D u_texture1;
+uniform sampler2D u_texture2;
+
+vec4 getFromColor (vec2 uv) {
+  return GskTexture(u_texture1, uv);
+}
+
+vec4 getToColor (vec2 uv) {
+  return GskTexture(u_texture2, uv);
+}
+
+// Source: https://gl-transitions.com/editor/wind
+// Author: gre
+// License: MIT
+
+const float size = 0.2;
+
+float rand(vec2 co) {
+  return fract(sin(dot(co.xy ,vec2(12.9898,78.233))) * 43758.5453);
+}
+
+vec4 transition(vec2 p) {
+  float r = rand(vec2(0, p.y));
+  float m = smoothstep(0.0, -size, p.x*(1.0-size) + size*r - (progress * (1.0 + size)));
+  return mix(getFromColor(p), getToColor(p), m);
+}
+
+
+void mainImage(out vec4 fragColor, in vec2 fragCoord, in vec2 resolution, in vec2 uv)
+{
+  fragColor = transition(uv);
+}

demos/icon-browser/data/symbolic/apps/org.gtk.IconBrowser4-symbolic.svg

@@ -0,0 +1,136 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<!-- Created with Inkscape (http://www.inkscape.org/) -->
+
+<svg
+   xmlns:osb="http://www.openswatchbook.org/uri/2009/osb"
+   xmlns:dc="http://purl.org/dc/elements/1.1/"
+   xmlns:cc="http://creativecommons.org/ns#"
+   xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
+   xmlns:svg="http://www.w3.org/2000/svg"
+   xmlns="http://www.w3.org/2000/svg"
+   xmlns:sodipodi="http://sodipodi.sourceforge.net/DTD/sodipodi-0.dtd"
+   xmlns:inkscape="http://www.inkscape.org/namespaces/inkscape"
+   sodipodi:docname="org.gtk.IconBrowser4-symbolic.svg"
+   height="16.03125"
+   id="svg7384"
+   inkscape:version="0.92.4 5da689c313, 2019-01-14"
+   version="1.1"
+   width="16">
+  <metadata
+     id="metadata90">
+    <rdf:RDF>
+      <cc:Work
+         rdf:about="">
+        <dc:format>image/svg+xml</dc:format>
+        <dc:type
+           rdf:resource="http://purl.org/dc/dcmitype/StillImage" />
+        <dc:title>Gnome Symbolic Icon Theme</dc:title>
+      </cc:Work>
+    </rdf:RDF>
+  </metadata>
+  <sodipodi:namedview
+     inkscape:bbox-paths="true"
+     bordercolor="#666666"
+     borderopacity="1"
+     inkscape:current-layer="layer9"
+     inkscape:cx="-2.5662459"
+     inkscape:cy="11.558672"
+     gridtolerance="10"
+     inkscape:guide-bbox="true"
+     guidetolerance="10"
+     id="namedview88"
+     inkscape:object-nodes="false"
+     inkscape:object-paths="false"
+     objecttolerance="10"
+     pagecolor="#555753"
+     inkscape:pageopacity="1"
+     inkscape:pageshadow="2"
+     showborder="true"
+     showgrid="false"
+     showguides="true"
+     inkscape:snap-bbox="true"
+     inkscape:snap-bbox-midpoints="false"
+     inkscape:snap-global="true"
+     inkscape:snap-grids="true"
+     inkscape:snap-nodes="true"
+     inkscape:snap-others="false"
+     inkscape:snap-to-guides="true"
+     inkscape:window-height="1375"
+     inkscape:window-maximized="1"
+     inkscape:window-width="2560"
+     inkscape:window-x="0"
+     inkscape:window-y="27"
+     inkscape:zoom="1">
+    <inkscape:grid
+       empspacing="2"
+       enabled="true"
+       id="grid4866"
+       originx="-203"
+       originy="-251.96875"
+       snapvisiblegridlinesonly="true"
+       spacingx="1"
+       spacingy="1"
+       type="xygrid"
+       visible="true" />
+  </sodipodi:namedview>
+  <title
+     id="title9167">Gnome Symbolic Icon Theme</title>
+  <defs
+     id="defs7386">
+    <linearGradient
+       id="linearGradient7212"
+       osb:paint="solid">
+      <stop
+         id="stop7214"
+         offset="0"
+         style="stop-color:#000000;stop-opacity:1;" />
+    </linearGradient>
+  </defs>
+  <g
+     inkscape:groupmode="layer"
+     id="layer9"
+     inkscape:label="apps"
+     style="display:inline"
+     transform="translate(-444.0002,35)">
+    <path
+       style="display:inline;opacity:1;vector-effect:none;fill:#000000;fill-opacity:1;stroke:none;stroke-width:2;stroke-linecap:butt;stroke-linejoin:bevel;stroke-miterlimit:4;stroke-dasharray:none;stroke-dashoffset:0;stroke-opacity:1;marker:none;marker-start:none;marker-mid:none;marker-end:none;paint-order:normal;enable-background:new"
+       d="m 457.9846,-27.96875 v -3 h 1 l -3,-3 -3,3 h 1 v 3 z"
+       id="path2809"
+       inkscape:connector-curvature="0"
+       sodipodi:nodetypes="cccccccc" />
+    <path
+       style="display:inline;opacity:1;vector-effect:none;fill:#000000;fill-opacity:1;stroke:none;stroke-width:2;stroke-linecap:butt;stroke-linejoin:bevel;stroke-miterlimit:4;stroke-dasharray:none;stroke-dashoffset:0;stroke-opacity:1;marker:none;marker-start:none;marker-mid:none;marker-end:none;paint-order:normal;enable-background:new"
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+       inkscape:connector-curvature="0"
+       sodipodi:nodetypes="ccccccc" />
+    <path
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+       d="m 455.9846,-24.96875 v 4 c 0,0 1,-1 1,-2 0,-1.31515 -1,-2 -1,-2 z"
+       id="path2813"
+       inkscape:connector-curvature="0"
+       sodipodi:nodetypes="ccsc" />
+    <path
+       style="display:inline;opacity:1;vector-effect:none;fill:#000000;fill-opacity:1;stroke:none;stroke-width:2;stroke-linecap:butt;stroke-linejoin:bevel;stroke-miterlimit:4;stroke-dasharray:none;stroke-dashoffset:0;stroke-opacity:1;marker:none;marker-start:none;marker-mid:none;marker-end:none;paint-order:normal;enable-background:new"
+       d="m 457.9846,-25.96875 v 6 c 0,0 1,-1.94591 1,-3 0,-1.05409 -1,-3 -1,-3 z"
+       id="path2815"
+       inkscape:connector-curvature="0"
+       sodipodi:nodetypes="ccsc" />
+    <path
+       inkscape:connector-curvature="0"
+       style="display:inline;opacity:1;fill:#000000;fill-opacity:1;stroke:none;stroke-width:2;enable-background:new"
+       d="m 450.53751,-25.96846 c 0.24647,0 0.44708,0.19694 0.44708,0.44708 v 0.0289 c -0.008,3.05189 -2.48438,5.5237 -5.53812,5.5237 h -0.0148 c -0.25145,0 -0.44711,-0.20581 -0.44711,-0.4615 v -0.46152 -0.92302 c 0,-0.25567 0.20581,-0.4615 0.4615,-0.4615 h 0.92302 c 0.25569,0 0.46152,0.20581 0.46152,0.4615 v 0.21634 c 1.18002,-0.41715 2.10674,-1.34386 2.52389,-2.52388 h -0.21635 c -0.25566,0 -0.4615,-0.20581 -0.4615,-0.46152 v -0.92302 c 0,-0.25567 0.20581,-0.4615 0.4615,-0.4615 h 0.46152 0.4615 0.44709 0.0148 0.0148 z"
+       id="rect5922-7-3" />
+    <g
+       id="g904-6"
+       transform="matrix(0.26785369,0,0,0.26785369,436.44908,-87.00581)"
+       style="display:inline;fill:#000000;fill-opacity:1;stroke-width:3.73338151;enable-background:new">
+      <path
+         sodipodi:nodetypes="csscccssssccccccsccsssssccccccsssss"
+         inkscape:connector-curvature="0"
+         style="color:#000000;clip-rule:nonzero;display:inline;overflow:visible;visibility:visible;opacity:1;isolation:auto;mix-blend-mode:normal;color-interpolation:sRGB;color-interpolation-filters:linearRGB;solid-color:#000000;solid-opacity:1;fill:#000000;fill-opacity:1;fill-rule:nonzero;stroke:none;stroke-width:7.46676302;stroke-linecap:butt;stroke-linejoin:miter;stroke-miterlimit:4;stroke-dasharray:none;stroke-dashoffset:0;stroke-opacity:1;color-rendering:auto;image-rendering:auto;shape-rendering:auto;text-rendering:auto;enable-background:accumulate"
+         d="m 37,198.00759 c -2.76142,0 -5,2.23858 -5,5 0,2.76142 2.23858,5 5,5 0.89216,0 1.71236,-0.27804 2.4375,-0.6875 l 3.9375,3.6875 -3.9375,3.6875 c -0.72514,-0.40946 -1.54534,-0.6875 -2.4375,-0.6875 -2.76142,0 -5,2.23858 -5,5 0,2.76142 2.23858,5 5,5 2.76142,0 5,-2.23858 5,-5 0,-0.45832 -0.072,-0.89082 -0.1874,-1.3125 l 4.25,-4.125 8.9374,8.4375 h 3 v -2 l -16.1875,-15.6875 c 0.1156,-0.42168 0.1874,-0.85418 0.1874,-1.3125 0,-2.76142 -2.23858,-5 -5,-5 z m 0,3 c 1.10456,0 2,0.89544 2,2 0,1.10456 -0.89544,2 -2,2 -1.10456,0 -2,-0.89544 -2,-2 0,-1.10456 0.89544,-2 2,-2 z m 18,-1 -7.875,7.4375 2.625,2.5625 8.25,-8 v -2 z m -18,17 c 1.10456,0 2,0.89544 2,2 0,1.10456 -0.89544,2 -2,2 -1.10456,0 -2,-0.89544 -2,-2 0,-1.10456 0.89544,-2 2,-2 z"
+         id="path1079-7" />
+    </g>
+  </g>
+</svg>

demos/icon-browser/iconbrowserapp.c

@@ -139,8 +139,6 @@ icon_browser_app_activate (GApplication *app)
   if (g_strcmp0 (PROFILE, "devel") == 0)
     gtk_widget_add_css_class (GTK_WIDGET (win), "devel");
 
-  gtk_window_set_icon_name (GTK_WINDOW (win), "org.gtk.IconBrowser4");
-
   gtk_window_present (GTK_WINDOW (win));
 }
 

demos/meson.build

@@ -3,7 +3,9 @@
 appdata_config = configuration_data()
 appdata_config.set('BUILD_VERSION', meson.project_version())
 
+subdir('constraint-editor')
 subdir('gtk-demo')
+subdir('icon-browser')
 subdir('node-editor')
 subdir('widget-factory')
 subdir('print-editor')

demos/node-editor/node-editor-application.c

@@ -219,8 +219,6 @@ node_editor_application_activate (GApplication *app)
   if (g_strcmp0 (PROFILE, "devel") == 0)
     gtk_widget_add_css_class (GTK_WIDGET (win), "devel");
 
-  gtk_window_set_icon_name (GTK_WINDOW (win), "org.gtk.gtk4.NodeEditor");
-
   gtk_window_present (GTK_WINDOW (win));
 }
 
@@ -301,7 +299,7 @@ node_editor_application_new (void)
 
   app = g_object_new (NODE_EDITOR_APPLICATION_TYPE,
                       "application-id", "org.gtk.gtk4.NodeEditor",
-                      "flags", G_APPLICATION_HANDLES_OPEN | G_APPLICATION_NON_UNIQUE,
+                      "flags", G_APPLICATION_HANDLES_OPEN,
                       NULL);
 
   g_application_add_main_option (G_APPLICATION (app), "version", 0, 0,G_OPTION_ARG_NONE, "Show program version", NULL);

demos/node-editor/node-editor-window.c

@@ -925,7 +925,7 @@ export_image_response_cb (GObject      *source,
       GdkTexture *texture;
       GskRenderer *renderer;
 
-      renderer = gsk_ngl_renderer_new ();
+      renderer = gsk_gl_renderer_new ();
       if (!gsk_renderer_realize_for_display (renderer, gdk_display_get_default (), NULL))
         {
           g_object_unref (renderer);
@@ -1205,19 +1205,6 @@ node_editor_window_add_renderer (NodeEditorWindow *self,
   g_object_unref (paintable);
 }
 
-static void
-update_paste_action (GdkClipboard *clipboard,
-                     GParamSpec   *pspec,
-                     gpointer      data)
-{
-  GtkWidget *widget = GTK_WIDGET (data);
-  gboolean has_node;
-
-  has_node = gdk_content_formats_contain_mime_type (gdk_clipboard_get_formats (clipboard), "application/x-gtk-render-node");
-
-  gtk_widget_action_set_enabled (widget, "paste-node", has_node);
-}
-
 static void
 node_editor_window_realize (GtkWidget *widget)
 {
@@ -1255,7 +1242,6 @@ node_editor_window_realize (GtkWidget *widget)
   self->after_paint_handler = g_signal_connect (frameclock, "after-paint",
                                                 G_CALLBACK (after_paint), self);
 
-  g_signal_connect (gtk_widget_get_clipboard (widget), "notify::formats", G_CALLBACK (update_paste_action), widget);
 }
 
 static void
@@ -1265,8 +1251,6 @@ node_editor_window_unrealize (GtkWidget *widget)
   GdkFrameClock *frameclock;
   guint i;
 
-  g_signal_handlers_disconnect_by_func (gtk_widget_get_clipboard (widget), update_paste_action, widget);
-
   frameclock = gtk_widget_get_frame_clock (widget);
   g_signal_handler_disconnect (frameclock, self->after_paint_handler);
   self->after_paint_handler = 0;
@@ -1631,41 +1615,6 @@ edit_action_cb (GtkWidget  *widget,
   node_editor_window_edit (self, &start);
 }
 
-static void
-text_received (GObject      *source,
-               GAsyncResult *result,
-               gpointer      data)
-{
-  GdkClipboard *clipboard = GDK_CLIPBOARD (source);
-  NodeEditorWindow *self = NODE_EDITOR_WINDOW (data);
-  char *text;
-
-  text = gdk_clipboard_read_text_finish (clipboard, result, NULL);
-  if (text)
-    {
-      GtkTextBuffer *buffer;
-      GtkTextIter start, end;
-
-      buffer = gtk_text_view_get_buffer (GTK_TEXT_VIEW (self->text_view));
-      gtk_text_buffer_begin_user_action (buffer);
-      gtk_text_buffer_get_bounds (buffer, &start, &end);
-      gtk_text_buffer_delete (buffer, &start, &end);
-      gtk_text_buffer_insert (buffer, &start, text, -1);
-      gtk_text_buffer_end_user_action (buffer);
-      g_free (text);
-    }
-}
-
-static void
-paste_node_cb (GtkWidget  *widget,
-               const char *action_name,
-               GVariant   *parameter)
-{
-  GdkClipboard *clipboard = gtk_widget_get_clipboard (widget);
-
-  gdk_clipboard_read_text_async (clipboard, NULL, text_received, widget);
-}
-
 static void
 node_editor_window_set_property (GObject      *object,
                                  guint         prop_id,
@@ -1778,13 +1727,6 @@ node_editor_window_class_init (NodeEditorWindowClass *class)
   action = gtk_named_action_new ("smart-edit");
   shortcut = gtk_shortcut_new (trigger, action);
   gtk_widget_class_add_shortcut (widget_class, shortcut);
-
-  gtk_widget_class_install_action (widget_class, "paste-node", NULL, paste_node_cb);
-
-  trigger = gtk_keyval_trigger_new (GDK_KEY_v, GDK_CONTROL_MASK | GDK_SHIFT_MASK);
-  action = gtk_named_action_new ("paste-node");
-  shortcut = gtk_shortcut_new (trigger, action);
-  gtk_widget_class_add_shortcut (widget_class, shortcut);
 }
 
 static GtkWidget *

demos/node-editor/node-editor-window.ui

@@ -22,10 +22,6 @@
   </menu>
   <menu id="extra_menu">
     <section>
-      <item>
-        <attribute name="label" translatable="yes">Paste _Node</attribute>
-        <attribute name="action">paste-node</attribute>
-      </item>
       <item>
         <attribute name="label" translatable="yes">Assisted _Edit</attribute>
         <attribute name="action">smart-edit</attribute>

demos/node-editor/node-editor.gresource.xml

@@ -3,7 +3,7 @@
   <gresource prefix="/org/gtk/gtk4/node-editor">
     <file preprocess="xml-stripblanks">node-editor-window.ui</file>
     <file preprocess="xml-stripblanks">help-window.ui</file>
-    <file alias='node-format.md'>../../docs/reference/gtk/node-format.md</file>
+    <file>node-format.md</file>
     <file alias='icons/apps/org.gtk.gtk4.NodeEditor.svg'>data/scalable/apps/org.gtk.gtk4.NodeEditor.svg</file>
   </gresource>
 </gresources>

demos/node-editor/node-format.md

@@ -1,15 +1,13 @@
-Title: The Node file format
+# The Node file format
 
 GSK render nodes can be serialized and deserialized using APIs such as `gsk_render_node_serialize()` and `gsk_render_node_deserialize()`. The intended use for this is development - primarily the development of GTK - by allowing things such as creating testsuites and benchmarks, exchanging nodes in bug reports. GTK includes the `gtk4-node-editor` application for creating such test files.
 
 The format is a text format that follows the [CSS syntax rules](https://drafts.csswg.org/css-syntax-3/). In particular, this means that every array of bytes will produce a render node when parsed, as there is a defined error recovery method. For more details on error handling, please refer to the documentation of the parsing APIs.
 
 The grammar of a node text representation using [the CSS value definition syntax](https://drafts.csswg.org/css-values-3/#value-defs) looks like this:
-
-    document: <@-rule>*<node>
-    @-rule: @cicp "name" { <property>* }
-    node: container [ "name" ] { <document> } | <node-type> [ "name" ] { <property>* } | "name"
-    property: <property-name>: <node> | <value> ;
+**document**: `<node>\*`
+**node**: container [ "name" ] { <document> } | `<node-type> [ "name" ] { <property>* }` | "name"
+**property**: `<property-name>: <node> | <value> ;`
 
 Each node has its own `<node-type>` and supports a custom set of properties, each with their own `<property-name>` and syntax. The following paragraphs document each of the nodes and their properties.
 
@@ -27,59 +25,6 @@ Nodes can be given a name by adding a string after the `<node-type>` in their de
 
 Just like nodes, textures can be referenced by name. When defining a named texture, the name has to be placed in front of the URL.
 
-# Color states
-
-Color states are represented either by an ident (for builtin ones) or a string
-(for custom ones):
-
-    color-state: <ident> | <string>
-
-Custom color states can be defined at the beginning of the document, with an @‌cicp rule.
-
-The format for @‌cicp rules is
-
-    @‌cicp "name" {
-      ...
-    }
-
-The following properties can be set for custom color states:
-
-| property  | syntax           | default  | printed     |
-| --------- | ---------------- | -------- | ----------- |
-| primaries | `<integer>`      | 2        | always      |
-| transfer  | `<integer>`      | 2        | always      |
-| matrix    | `<integer>`      | 2        | always      |
-| range     | `<range>`        | full     | non-default |
-
-Note that the primaries, transfer and matrix properties always need
-to be specified, since GTK does not allow creating color state objects
-with these being set to 2 (== unspecified).
-
-Range can have the following values:
-
-    range: narrow | full
-
-# Colors
-
-Colors can be specified with a variation of the modern CSS color syntax:
-
-    color(<color-state> <number> <number> <number> ["/" <number>])
-
-The traditional syntax for sRGB colors still works as well:
-
-    rgba(<number>, <number>, <number>, <number)
-    rgb(<number, <number>, <number>)
-
-# Rectangles
-
-Rectangles can be specified just as four integers for x, y, width and height:
-
-    rect: <number> <number> <number> <number>
-
-Rounded rectangles use a CSS-like syntax:
-
-    rounded-rect: <rect> [ "/" <number>{1,4} [ "/" <number>{1,4} ] ]
-
 # Nodes
 
 ### container
@@ -96,13 +41,6 @@ The **container** node is a special node that allows specifying a list of child
 
 Creates a node like `gsk_blend_node_new()` with the given properties.
 
-Possible values for the mode property are:
-
-    blend-mode: normal | multiply | screen | overlay | darken |
-                lighten | color-dodge | color-burn | hard-light |
-                soft-light | difference | exclusion | color |
-                hue | saturation | luminosity
-
 ### blur
 
 | property | syntax           | default                | printed     |
@@ -222,10 +160,6 @@ Creates a node like `gsk_fill_node_new()` with the given properties.
 The default child node is the default color node, but created with the
 bounds of the path.
 
-Possible values for the fill-rule property are:
-
-    fill-rule: winding | even-odd
-
 ### glshader
 
 | property   | syntax             | default                | printed     |
@@ -277,10 +211,6 @@ Creates a node like `gsk_linear_gradient_node_new()` with the given properties.
 
 Creates a node like `gsk_mask_node_new()` with the given properties.
 
-Possible values for the mode property are:
-
-    mask-mode: alpha | inverted-alpha | luminance | inverted-luminance
-
 ### opacity
 
 | property | syntax           | default                | printed     |
@@ -319,11 +249,11 @@ Creates a node like `gsk_radial_gradient_node_new()` with the given properties.
 
 ### repeat
 
-| property     | syntax     | default                | printed     |
-| ------------ | ---------- | ---------------------- | ----------- |
-| bounds       | `<rect>`   | *bounds of child node* | non-default |
-| child        | `<node>`   | color { }              | always      |
-| child-bounds | `<rect>`   | *bounds of child node* | non-default |
+| property    | syntax           | default                | printed     |
+| ----------- | ---------------- | ---------------------- | ----------- |
+| bounds      | `<rect>`         | *bounds of child node* | non-default |
+| child       | `<node>`         | color { }              | always      |
+| child-bounds| `<rect>`         | *bounds of child node* | non-default |
 
 Creates a node like `gsk_repeat_node_new()` with the given properties.
 
@@ -390,14 +320,6 @@ Creates a node like `gsk_stroke_node_new()` with the given properties.
 The default child node is the default color node, but created with the
 stroke bounds of the path.
 
-Possible values for the line-cap property are:
-
-    line-cap: butt | round | square
-
-Possible values for the line-join property are:
-
-    line-join: miter | round | bevel
-
 ### text
 
 | property     | syntax              | default             | printed     |
@@ -406,9 +328,8 @@ Possible values for the line-join property are:
 | font         | `<string>` `<url>`? | "Cantarell 15px"    | always      |
 | glyphs       | `<glyphs>`          | "Hello"             | always      |
 | offset       | `<point>`           | 0 0                 | non-default |
-| hint-style   | `<hint-style>`      | slight              | non-default |
+| hint-style   | `<hint style>`      | slight              | non-default |
 | antialias    | `<antialias>`       | gray                | non-default |
-| hint-metrics | `<hint-metrics>`    | off                 | non-default |
 
 Creates a node like `gsk_text_node_new()` with the given properties.
 
@@ -423,17 +344,8 @@ be specified as well, like this: 40 10 0 0 color.
 If the given font does not exist or the given glyphs are invalid for the given
 font, an error node will be returned.
 
-Possible values for the hint-style property are:
-
-    hint-style: none | slight | full
-
-Possible value for the antialias property are:
-
-    antialias:  none | gray
-
-Possible value for hint-metrics are:
-
-    hint-metrics:  on | off
+Possible values for hint-style are none, slight or full.
+Possible value for antialias are none or gray.
 
 ### texture
 
@@ -459,15 +371,14 @@ representation for this texture is `url("data:image/png;base64,iVBORw0KGgoAAAANS
 | -------- | ---------------- | ---------------------- | ----------- |
 | bounds   | `<rect>`         | 50                     | always      |
 | texture  | `<url>`          | *see below*            | always      |
-| filter   | `filter`         | linear                 | non-default |
+| filter   | `filter`         | *see below*            | non-default |
 
 Creates a node like `gsk_texture_scale_node_new()` with the given properties.
 
 The default texture is a 10x10 checkerboard, just like for texture.
 
-Possible values for the filter property are:
-
-    filter: linear | nearest | trilinear
+The possible filter values are `linear`, `nearest` and `trilinear`, with
+`linear` being the default.
 
 ### transform
 

demos/print-editor/print-editor.c

@@ -798,7 +798,7 @@ activate (GApplication *app)
   if (g_strcmp0 (PROFILE, "devel") == 0)
     gtk_widget_add_css_class (GTK_WIDGET (main_window), "devel");
 
-  gtk_window_set_icon_name (GTK_WINDOW (main_window), "org.gtk.PrintEditor4");
+  gtk_window_set_icon_name (GTK_WINDOW (main_window), "text-editor");
   gtk_window_set_default_size (GTK_WINDOW (main_window), 400, 600);
   gtk_application_window_set_show_menubar (GTK_APPLICATION_WINDOW (main_window), TRUE);
   update_title (GTK_WINDOW (main_window));

demos/widget-factory/widget-factory.c

@@ -2241,7 +2241,6 @@ activate (GApplication *app)
   if (g_strcmp0 (PROFILE, "devel") == 0)
     gtk_widget_add_css_class (GTK_WIDGET (window), "devel");
 
-  gtk_window_set_icon_name (window, "org.gtk.WidgetFactory4");
   gtk_application_add_window (GTK_APPLICATION (app), window);
   g_action_map_add_action_entries (G_ACTION_MAP (window),
                                    win_entries, G_N_ELEMENTS (win_entries),

docs/reference/README.md

@@ -151,11 +151,10 @@ Checks whether the widget is set to be visible or not.
  - Methods are special functions whose first argument is always the instance
    of a certain class. The instance argument for newly written code should be
    called `self`.
- - If a method is a setter or a getter for an object property
-   `GtkClassName:prop-name`, and if its name does not match the naming scheme
-   `gtk_class_name_{g,s}et_prop_name`, you should add a `(set-property
-   prop-name)` or a `(get-property prop-name)` annotation to the method's
-   identifier
+ - If a method is a setter or a getter for an object property, you should
+   add an `(attributes org.gtk.Method.set_property=property-name)` or a
+   an `(attributes org.gtk.Method.get_property=property-name)` annotation
+   to the method's identifier
  - If a method changes one or more properties as side effect, link those
    properties in the method's description
  - If a method is a signal emitter, you should use the
@@ -193,10 +192,9 @@ Checks whether the widget is set to be visible or not.
    purposes.
  - Always note if setting a property has side effects, like causing another
    property to change state.
- - If a property `GtkClassName:prop-name` has a public getter or setter, and
-   they do not match the naming scheme `gtk_class_name_{g,s}et_prop_name` you
-   should annotate it with the `(setter setter_function)` and `(getter
-   getter_function)`.
+ - If the property has public accessors you should annotate it with
+   the `(attributes org.gtk.Property.set=setter_function)` and
+   `(attributes org.gtk.Property.get=getter_function)` attributes
  - The syntax for property documentation is:
 
 ```c

docs/reference/gdk/cairo.md

@@ -5,11 +5,8 @@ Title: Cairo interaction
 [Cairo](http://cairographics.org) is a graphics library that supports vector
 graphics and image compositing that can be used with GTK.
 
-GDK does not wrap the Cairo API and it is not possible to use cairo directly
-to draw on a [class@Gdk.Surface]. You can either use a
-[GtkDrawingArea](../gtk4/class.DrawingArea.html) widget or
-[gtk_snapshot_append_cairo](../gtk4/func.Snapshot.append_cairo.html)
-for drawing with cairo in a GTK4 application.
+GDK does not wrap the Cairo API; instead it allows to create Cairo
+drawing contexts which can be used to draw on [class@Gdk.Surface]s.
 
 Additional functions allow use [struct@Gdk.Rectangle]s with Cairo
 and to use [struct@Gdk.RGBA], `GdkPixbuf`, and [class@Gdk.Surface]

docs/reference/gdk/gdk4.toml.in

@@ -111,11 +111,3 @@ content_images = [
 ]
 content_base_url = "https://gitlab.gnome.org/GNOME/gtk/-/blob/main/docs/reference/gdk/"
 urlmap_file = "urlmap.js"
-
-[[object]]
-name = "DECLARE_INTERNAL_TYPE"
-hidden = true
-
-[[object]]
-pattern = "KEY_*"
-check_ignore = true