wip: api for exact points

Eventually, this should replace gsk_path_builder_add_segment.
For now, add it under a different name.

.clang-format

@@ -1,4 +1,4 @@
-# See https://www.apertis.org/policies/coding_conventions/#code-formatting
+# See https://wiki.apertis.org/Guidelines/Coding_conventions#Code_formatting
 BasedOnStyle: GNU
 AlwaysBreakAfterDefinitionReturnType: All
 BreakBeforeBinaryOperators: None

.flake8

@@ -1,2 +0,0 @@
-[flake8]
-ignore = E501

.gitlab-ci.yml

@@ -26,21 +26,12 @@ 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:v46"
 
 workflow:
   rules:
-    # run merge request pipelines
-    - if: $CI_PIPELINE_SOURCE == "merge_request_event"
-    # do not run branch pipelines if corresponding merge requests exist...
-    # (this avoids duplicate pipelines)
-    - if: $CI_COMMIT_BRANCH && $CI_OPEN_MERGE_REQUESTS
-      when: never
-    # ...but otherwise run branch pipelines
-    - if: $CI_COMMIT_BRANCH
-    # run tag pipelines
     - if: $CI_COMMIT_TAG
+    - if: $CI_COMMIT_BRANCH
 
 default:
   retry:
@@ -67,7 +58,7 @@ style-check-diff:
       junit:
         - "${CI_PROJECT_DIR}/_build/report-x11.xml"
         - "${CI_PROJECT_DIR}/_build/report-wayland.xml"
-        - "${CI_PROJECT_DIR}/_build/report-wayland_gl.xml"
+        - "${CI_PROJECT_DIR}/_build/report-wayland_gles.xml"
         - "${CI_PROJECT_DIR}/_build/report-broadway.xml"
     name: "gtk-${CI_COMMIT_REF_NAME}"
     paths:
@@ -78,7 +69,6 @@ style-check-diff:
       - "${CI_PROJECT_DIR}/_build/testsuite/reftests/output/*/*.node"
       - "${CI_PROJECT_DIR}/_build/testsuite/tools/output/*/*"
       - "${CI_PROJECT_DIR}/_build/testsuite/gsk/compare/*/*/*.png"
-      - "${CI_PROJECT_DIR}/_build/testsuite/gsk/compare/*/*/*.node"
       - "${CI_PROJECT_DIR}/_build/testsuite/css/output/*/*.syscap"
       - "${CI_PROJECT_DIR}/_build/testsuite/headless/*/*.log"
       - "${CI_PROJECT_DIR}/_build_hello/meson-logs"
@@ -105,9 +95,8 @@ fedora-x86_64:
             ${FEATURE_FLAGS}
             _build
     - meson compile -C _build
-    - .gitlab-ci/run-tests.sh _build x11 gtk
-    # only repeat test runs that are likely affected by test setups
-    - .gitlab-ci/run-tests.sh _build wayland_gl gtk:gdk,gtk:gsk-gl
+    - .gitlab-ci/run-tests.sh _build wayland
+    - .gitlab-ci/run-tests.sh _build wayland_gles
 
 release-build:
   extends: .build-fedora-default
@@ -117,12 +106,10 @@ 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
             ${COMMON_MESON_FLAGS}
@@ -134,7 +121,7 @@ release-build:
     - meson install -C _build
     - PKG_CONFIG_PATH=${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
+    - .gitlab-ci/run-tests.sh _build x11
 
 fedora-clang:
   extends: .build-fedora-default
@@ -198,11 +185,11 @@ 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
@@ -211,53 +198,34 @@ msys2-ucrt64:
       - "${CI_PROJECT_DIR}/_build/gtkdll.tar.gz"
 
 macos:
+  # Sadly, this fails regularly, and its failure is never enlightening
+  allow_failure: true
   rules:
-    # Do not run in forks as the runner is not available there.
-    # (except for dehesselle who maintains the runner)
-    - if: $CI_PROJECT_NAMESPACE != "GNOME" && $CI_PROJECT_NAMESPACE != "dehesselle"
-      when: never
-    - if: $RUNNER == "macosintel"
-      variables:
-        SDKROOT: /opt/sdks/MacOSX10.13.4.sdk
-        NINJA_PKG: $CI_API_V4_URL/projects/30745/packages/generic/ninja_macos/v1.11.1.1+9/ninja-1.11.1.1-cp38-cp38-macosx_11_0_x86_64.whl
-      when: manual
-      allow_failure: true
-    - if: $RUNNER == "macosarm"
-      variables:
-        SDKROOT: /opt/sdks/MacOSX11.3.sdk
-        NINJA_PKG: ninja==1.11.1.1
+    - if: $CI_PROJECT_NAMESPACE == "GNOME"
   stage: build
-  parallel:
-    matrix:
-      - RUNNER: [ "macosintel", "macosarm" ]
   tags:
-    - ${RUNNER}
+    - macos
   needs: []
-  variables:
-    EXTRA_MESON_FLAGS: ""
-    BACKEND_FLAGS: "-Dx11-backend=false -Dbroadway-backend=true"
-    FEATURE_FLAGS: "-Dmedia-gstreamer=disabled -Dintrospection=enabled -Dgobject-introspection:werror=false"
-    TMPDIR: /Users/Shared/work/tmp
-    PIP_CACHE_DIR: /Users/Shared/build/cache
-    PIPENV_CACHE_DIR: $PIP_CACHE_DIR
-    PYTHONPYCACHEPREFIX: $PIP_CACHE_DIR
   before_script:
-    - .gitlab-ci/show-info-macos.sh
-    - python3 -m venv .venv
-    # Building the introspection feature requires pkg-config and bison.
-    - curl -L $CI_API_V4_URL/projects/30437/packages/generic/pkgconfig/v0.29.2+10/pkg-config-0.29.2+10_$(uname -m).tar.xz | tar -C .venv -xJ
-    - curl -L $CI_API_V4_URL/projects/30438/packages/generic/bison/v3.8.2+3/bison-3.8.2+3_$(uname -m).tar.xz | tar -C .venv -xJ
-    - source .venv/bin/activate
-    - pip3 install meson==1.3.2 $NINJA_PKG
-    # We're not setting up ccache here on purpose as it accelerates the build
-    # so much that it triggers race conditions in the gobject-introspection
-    # subproject.
+    - bash .gitlab-ci/show-info-osx.sh
+    - pip3 install --user meson~=1.0
+    - pip3 install --user ninja
+    - export PATH=/Users/gitlabrunner/Library/Python/3.7/bin:$PATH
+    - export MESON_FORCE_BACKTRACE=1
   script:
-    - meson setup
-            ${COMMON_MESON_FLAGS}
-            ${EXTRA_MESON_FLAGS}
-            ${BACKEND_FLAGS}
-            ${FEATURE_FLAGS}
+    - meson setup ${COMMON_MESON_FLAGS}
+            -Dx11-backend=false
+            -Dbroadway-backend=true
+            -Dmacos-backend=true
+            -Dmedia-gstreamer=disabled
+            -Dintrospection=disabled
+            -Dcpp_std=c++11
+            -Dpixman:tests=disabled
+            -Dlibjpeg-turbo:simd=disabled
+            -Dbuild-demos=false
+            -Dbuild-tests=false
+            -Dbuild-examples=false
+            -Dbuild-testsuite=false
             _build
     - meson compile -C _build
   artifacts:
@@ -413,12 +381,11 @@ 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:$PATH"
     - CC=clang meson setup
@@ -432,7 +399,13 @@ asan-build:
             -Df16c=disabled
             _build
     - ninja -C _build
-    - .gitlab-ci/run-tests.sh _build wayland gtk
+    - .gitlab-ci/run-tests.sh _build wayland
+    - .gitlab-ci/run-tests.sh _build wayland_gles
+    - .gitlab-ci/run-tests.sh _build x11
+  artifacts:
+    when: always
+    paths:
+      - "${CI_PROJECT_DIR}/_build/meson-logs"
 
 reference:
   image: $FEDORA_IMAGE
@@ -445,11 +418,10 @@ reference:
             --buildtype=release
             --force-fallback-for=gdk-pixbuf,pango
             -Dintrospection=enabled
-            -Ddocumentation=true
-            -Dman-pages=true
+            -Dgtk_doc=true
             -Dgdk-pixbuf:gtk_doc=true
-            -Dpango:documentation=true
-            -Dbuild-demos=true
+            -Dpango:gtk_doc=true
+            -Ddemos=false
             -Dbuild-examples=false
             -Dbuild-tests=false
             -Dbuild-testsuite=false
@@ -461,7 +433,6 @@ reference:
     - mv _build/docs/reference/gdk/gdk4-wayland/ _reference/gdk4-wayland/
     - mv _build/docs/reference/gsk/gsk4/ _reference/gsk4/
     - mv _build/docs/reference/gtk/gtk4/ _reference/gtk4/
-    - mv _build/docs/reference/gtk/*.html _reference/gtk4/
     - mv _build/subprojects/pango/docs/Pango/ _reference/Pango/
     - mv _build/subprojects/pango/docs/PangoCairo/ _reference/PangoCairo/
     - mv _build/subprojects/pango/docs/PangoFc/ _reference/PangoFc/
@@ -483,4 +454,3 @@ publish-docs:
     - "curl -X POST -F token=${PAGES_TRIGGER_TOKEN} -F ref=docs-gtk-org https://gitlab.gnome.org/api/v4/projects/665/trigger/pipeline"
   rules:
     - if: $CI_COMMIT_REF_NAME == "main"
-

.gitlab-ci/fedora.Dockerfile

@@ -1,7 +1,9 @@
-FROM fedora:40
+FROM fedora:38
 
 RUN dnf -y install \
     adwaita-icon-theme \
+    atk-devel \
+    at-spi2-atk-devel \
     avahi-gobject-devel \
     cairo-devel \
     cairo-gobject-devel \
@@ -16,6 +18,7 @@ RUN dnf -y install \
     dejavu-sans-mono-fonts \
     desktop-file-utils \
     diffutils \
+    docbook-style-xsl \
     elfutils-libelf-devel \
     expat-devel \
     fribidi-devel \
@@ -29,7 +32,6 @@ RUN dnf -y install \
     glib2-static \
     glibc-devel \
     glibc-headers \
-    glslc \
     gnupg2 \
     gobject-introspection-devel \
     graphene-devel \
@@ -99,11 +101,8 @@ 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

@@ -23,11 +23,11 @@ flatpak build ${builddir} meson \
                 -Dbuild-testsuite=false \
                 -Dbuild-examples=false \
                 -Dintrospection=disabled \
-                -Dbuild-demos=true \
+                -Ddemos=true \
                 -Dprofile=devel \
                 _flatpak_build
 
-flatpak build --env=CI_COMMIT_SHORT_SHA=$CI_COMMIT_SHORT_SHA ${builddir} ninja -C _flatpak_build install
+flatpak build ${builddir} ninja -C _flatpak_build install
 
 flatpak-builder \
         --user --disable-rofiles-fuse \

.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/meson-html-report.py

@@ -324,7 +324,7 @@ for line in args.infile:
     units.append(unit)
 
 report = {}
-report['date'] = datetime.datetime.now(datetime.UTC)
+report['date'] = datetime.datetime.utcnow()
 report['locale_date'] = report['date'].strftime("%c")
 report['project_name'] = args.project_name
 report['backend'] = args.backend

.gitlab-ci/meson-junit-report.py

@@ -44,7 +44,7 @@ outfile = args.output
 testsuites = ET.Element('testsuites')
 testsuites.set('id', '{}/{}'.format(args.job_id, args.branch))
 testsuites.set('package', args.project_name)
-testsuites.set('timestamp', datetime.datetime.now(datetime.UTC).isoformat(timespec='minutes'))
+testsuites.set('timestamp', datetime.datetime.utcnow().isoformat(timespec='minutes'))
 
 suites = {}
 for line in args.infile:

.gitlab-ci/run-single-test.sh

@@ -1,32 +0,0 @@
-#!/usr/bin/sh
-#
-builddir=$1
-suite=$2
-unit=$3
-
-echo "** builddir: ${builddir}"
-echo "**    suite: ${suite}"
-echo "**     unit: ${unit}"
-
-export XDG_RUNTIME_DIR="$(mktemp -p $(pwd) -d xdg-runtime-XXXXXX)"
-
-weston --backend=headless-backend.so --socket=wayland-5 --idle-time=0 &
-compositor=$!
-
-export WAYLAND_DISPLAY=wayland-5
-
-meson test -C ${builddir} \
-            --print-errorlogs \
-            --setup=wayland \
-            --suite=${suite} \
-            --no-suite=failing \
-            --no-suite=flaky \
-            --no-suite=wayland_failing \
-            --no-suite=gsk-compare-broadway \
-            --verbose \
-            "${unit}"
-
-exit_code=$?
-kill ${compositor}
-
-exit ${exit_code}

.gitlab-ci/run-tests.sh

@@ -1,33 +1,28 @@
 #!/bin/bash
 
-set -x
+set +x
 set +e
 
 srcdir=$( pwd )
 builddir=$1
-setup=$2
-suite=$3
+backend=$2
 multiplier=${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 "${setup}" in
-  x11*)
-    dbus-run-session -- \
-       xvfb-run -a -s "-screen 0 1024x768x24 -noreset" \
+case "${backend}" in
+  x11)
+    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=${suite//,/ --suite=} \
+                --setup=${backend} \
+                --suite=gtk \
                 --no-suite=failing \
-                --no-suite=${setup}_failing \
                 --no-suite=flaky \
-                --no-suite=headless \
                 --no-suite=gsk-compare-broadway
 
     # Store the exit code for the CI run, but always
@@ -42,50 +37,43 @@ 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=${suite//,/ --suite=} \
+                --setup=${backend} \
+                --suite=gtk \
                 --no-suite=failing \
-                --no-suite=${setup}_failing \
                 --no-suite=flaky \
-                --no-suite=headless \
+                --no-suite=${backend}_failing \
                 --no-suite=gsk-compare-broadway
     exit_code=$?
 
     kill ${compositor}
     ;;
 
-  broadway*)
+  broadway)
     export XDG_RUNTIME_DIR="$(mktemp -p $(pwd) -d xdg-runtime-XXXXXX)"
 
     ${builddir}/gdk/broadway/gtk4-broadwayd :5 &
     server=$!
     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=${suite//,/ --suite=} \
+                --setup=${backend} \
+                --suite=gtk \
                 --no-suite=failing \
-                --no-suite=${setup}_failing \
                 --no-suite=flaky \
-                --no-suite=headless \
                 --no-suite=gsk-compare-opengl
 
     kill ${server}
     ;;
 
   *)
-    echo "Failed to add ${setup} to .gitlab-ci/run-tests.sh"
+    echo "Failed to add ${backend} to .gitlab-ci/run-tests.sh"
     exit 1
     ;;
 
@@ -95,17 +83,17 @@ cd ${builddir}
 
 $srcdir/.gitlab-ci/meson-junit-report.py \
             --project-name=gtk \
-            --backend="${setup}" \
+            --backend="${backend}" \
             --job-id="${CI_JOB_NAME}" \
-            --output="report-${setup}.xml" \
-            "meson-logs/testlog-${setup}.json"
+            --output="report-${backend}.xml" \
+            "meson-logs/testlog-${backend}.json"
 
 $srcdir/.gitlab-ci/meson-html-report.py \
             --project-name=gtk \
-            --backend="${setup}" \
+            --backend="${backend}" \
             --job-id="${CI_JOB_NAME}" \
-            --reftest-output-dir="testsuite/reftests/output/${setup}" \
-            --output="report-${setup}.html" \
-            "meson-logs/testlog-${setup}.json"
+            --reftest-output-dir="testsuite/reftests/output/${backend}" \
+            --output="report-${backend}.html" \
+            "meson-logs/testlog-${backend}.json"
 
 exit $exit_code

.gitlab-ci/show-info-osx.sh

@@ -3,11 +3,6 @@
 set -eux -o pipefail
 
 xcodebuild -version || :
-
-if [ -z "$SDKROOT" ]; then
-  xcodebuild -showsdks || :
-else
-  echo "SDKROOT = $SDKROOT"
-fi
+xcodebuild -showsdks || :
 
 system_profiler SPSoftwareDataType || :

.gitlab-ci/test-msvc.bat

@@ -6,7 +6,7 @@ call "C:\Program Files (x86)\Microsoft Visual Studio\2017\BuildTools\VC\Auxiliar
 
 :: FIXME: make warnings fatal
 pip3 install --upgrade --user meson~=0.64 || goto :error
-meson setup -Dbackend_max_links=1 -Ddebug=false -Dmedia-gstreamer=disabled -Dvulkan=disabled _build || goto :error
+meson -Ddebug=false -Dmedia-gstreamer=disabled _build || goto :error
 ninja -C _build || goto :error
 
 goto :EOF

.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 +15,24 @@ 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
 
 mkdir -p _ccache
 export CCACHE_BASEDIR="$(pwd)"
@@ -39,10 +42,11 @@ export CCACHE_DIR="${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 \
+    -Dvulkan=disabled \
     -Dintrospection=enabled \
     -Dgtk:werror=true \
     _build

.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
 -->
 

AUTHORS

@@ -7,7 +7,7 @@ Peter Mattis      <petm@xcf.berkeley.edu>
 Spencer Kimball   <spencer@xcf.berkeley.edu>
 Josh MacDonald    <jmacd@xcf.berkeley.edu>
 
-The team that build GTK 2 (in alphabetical order)
+The Team that build GTK 2 (in alphabetical order)
 -------------------------------------------------
 Shawn T. Amundson <amundson@gtk.org>
 Jerome Bolliet    <bolliet@gtk.org>
@@ -28,8 +28,9 @@ Jay Painter       <jpaint@gtk.org>
 Manish Singh      <manish@gtk.org>
 Owen Taylor       <otaylor@gtk.org>
 
-The team that built GTK 3
--------------------------
+The current team (GTK 3 and 4)
+------------------------------
+
 Jonas Ådahl       <jadahl@gmail.com>
 Tim Bäder         <mail@baedert.org>
 Emmanuele Bassi   <ebassi@gnome.org>
@@ -39,16 +40,6 @@ Carlos Garnacho   <mrgarnacho@gmail.com>
 Alexander Larsson <alexl@redhat.com>
 Benjamin Otte     <otte@gnome.org>
 
-The current team (GTK 4)
-------------------------
-Jonas Ådahl       <jadahl@gmail.com>
-Emmanuele Bassi   <ebassi@gnome.org>
-Christian Hergert <chergert@gnome.org>
-Chun-wei Fan      <fanchunwei@src.gnome.org>
-Matthias Clasen   <mclasen@redhat.com>
-Carlos Garnacho   <mrgarnacho@gmail.com>
-Benjamin Otte     <otte@gnome.org>
-
 
 There are many others who have contributed patches; we thank them,
 GTK is much better because of them.
@@ -58,15 +49,35 @@ Over time, GTK has incorporated some pieces of software which
 started as independent projects. We list the original authors here:
 
 
+MS-Windows theme engine
+-----------------------
+Raymond Penners
+Dom Lachowicz
+
+
+Pixbuf theme engine
+-------------------
+Owen Taylor
+
+
 IME input method
 ----------------
 Takuro Ashie
 Kazuki IWAMOTO
 
-MacOS backend
--------------
+
+Mac OS X backend
+----------------
 Anders Carlsson
 
-GtkInspector (originally gtkparasite)
--------------------------------------
+
+DirectFB backend
+----------------
+Denis Oliver Kropp
+Sven Neumann
+Mike Emmel
+
+
+gtkparasite
+-----------
 Christian Hammond

CONTRIBUTING.md

@@ -35,7 +35,8 @@ 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, send an email to the [security](mailto:security@gnome.org)
+mailing list.
 
 ### Bug reports
 
@@ -100,16 +101,14 @@ 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 +132,7 @@ 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 +145,33 @@ $ 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.
@@ -210,7 +214,7 @@ Closes #1234
  `git commit -a --author "Joe Coder <joe@coder.org>"` and `--signoff`.
 
  - If your commit is addressing an issue, use the
- [GitLab syntax](https://docs.gitlab.com/ee/user/project/issues/managing_issues.html#closing-issues-automatically)
+ [GitLab syntax](https://docs.gitlab.com/ce/user/project/issues/automatic_issue_closing.html)
  to automatically close the issue when merging the commit with the upstream
  repository:
 
@@ -240,11 +244,13 @@ people committing to GTK to follow a few rules:
    code, you should always ask. If your change is minor and you've been
    working on GTK for a while it probably isn't necessary to ask. But when
    in doubt, ask. Even if your change is correct, somebody may know a
-   better way to do things.
-   The `gtk` [room on matrix](https://matrix.to/#/#gtk:gnome.org) is also a
-   good place to find GTK developers to discuss changes, but if you live
-   outside of the EU/US time zones, the [gtk tag on the GNOME Discourse instance](https://discourse.gnome.org/tag/gtk)
-   is the most certain and preferred method.
+   better way to do things. If you are making changes to GTK, you should
+   be subscribed to the [gtk-devel](https://mail.gnome.org/mailman/listinfo/gtk-devel-list)
+   mailing list; this is a good place to ask about intended changes.
+   The `#gtk` IRC channel on irc.gnome.org is also a good place to find GTK
+   developers to discuss changes, but if you live outside of the EU/US time
+   zones, an email to the gtk-devel mailing list is the most certain and
+   preferred method.
 
 0. Ask _first_.
 
@@ -259,4 +265,4 @@ 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).

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)
@@ -70,13 +67,6 @@ building for:
   - [Graphene](https://github.com/ebassi/graphene)
   - [Xkb-common](https://github.com/xkbcommon/libxkbcommon)
 
-If you are building the Wayland backend, you will also need:
-
-  - Wayland-client
-  - Wayland-protocols
-  - Wayland-cursor
-  - Wayland-EGL
-
 If you are building the X11 backend, you will also need:
 
   - Xlib, and the following X extensions:
@@ -89,24 +79,32 @@ If you are building the X11 backend, you will also need:
     - xdamage
     - xcomposite
 
+If you are building the Wayland backend, you will also need:
+
+  - Wayland-client
+  - Wayland-protocols
+  - Wayland-cursor
+  - Wayland-EGL
+
 Once you have all the necessary dependencies, you can build GTK by using
 Meson:
 
 ```sh
-$ meson setup _build
-$ meson compile -C_build
+$ meson _build .
+$ cd _build
+$ ninja
 ```
 
 You can run the test suite using:
 
 ```sh
-$ meson test -C_build
+$ meson test
 ```
 
 And, finally, you can install GTK using:
 
 ```
-$ sudo meson install -C_build
+$ sudo ninja install
 ```
 
 Complete information about installing GTK and related libraries
@@ -128,7 +126,7 @@ 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 +134,9 @@ 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"
         }
     }

build-aux/msvc/msvc_recommended_pragmas.h

@@ -1,41 +0,0 @@
-#ifndef _MSC_VER
-#pragma error "This header is for Microsoft VC or clang-cl only."
-#endif /* _MSC_VER */
-
-/* Make MSVC more pedantic, this is a recommended pragma list
- * from _Win32_Programming_ by Rector and Newcomer.
- */
-#ifndef __clang__
-#pragma warning(error:4002) /* too many actual parameters for macro */
-#pragma warning(error:4003) /* not enough actual parameters for macro */
-#pragma warning(1:4010)     /* single-line comment contains line-continuation character */
-#pragma warning(error:4013) /* 'function' undefined; assuming extern returning int */
-#pragma warning(1:4016)     /* no function return type; using int as default */
-#pragma warning(error:4020) /* too many actual parameters */
-#pragma warning(error:4021) /* too few actual parameters */
-#pragma warning(error:4027) /* function declared without formal parameter list */
-#pragma warning(error:4029) /* declared formal parameter list different from definition */
-#pragma warning(error:4033) /* 'function' must return a value */
-#pragma warning(error:4035) /* 'function' : no return value */
-#pragma warning(error:4045) /* array bounds overflow */
-#pragma warning(error:4047) /* different levels of indirection */
-#pragma warning(error:4049) /* terminating line number emission */
-#pragma warning(error:4053) /* An expression of type void was used as an operand */
-#pragma warning(error:4071) /* no function prototype given */
-#pragma warning(disable:4101) /* unreferenced local variable */
-#pragma warning(error:4150)
-
-/* G_NORETURN */
-#pragma warning(error:4646) /* function declared with __declspec(noreturn) has non-void return type */
-#pragma warning(error:4715) /* 'function': not all control paths return a value */
-#pragma warning(error:4098) /* 'void' function returning a value */
-
-#pragma warning(disable:4244)	/* No possible loss of data warnings */
-#pragma warning(disable:4305)   /* No truncation from int to char warnings */
-
-#pragma warning(error:4819) /* The file contains a character that cannot be represented in the current code page */
-#endif                      /* __clang__ */
-
-/* work around Microsoft's premature attempt to deprecate the C-Library */
-#define _CRT_SECURE_NO_WARNINGS
-#define _CRT_NONSTDC_NO_WARNINGS

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

@@ -1,9 +1,5 @@
-/* gtkatspisocketprivate.h: AT-SPI socket object
- *
- * Copyright 2024 GNOME Foundation Inc.
- *           2024 Igalia S.L.
- *
- * SPDX-License-Identifier: LGPL-2.1-or-later
+/*
+ * 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
@@ -16,19 +12,17 @@
  * 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/>.
+ * License along with this library. If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Authors: Matthias Clasen
  */
 
 #pragma once
 
-#include <gio/gio.h>
-#include "gtkaccessible.h"
-#include "gtkatspisocket.h"
+#include <gtk/gtk.h>
 
-G_BEGIN_DECLS
+#define CONSTRAINT_EDITOR_APPLICATION_TYPE (constraint_editor_application_get_type ())
 
-GVariant * gtk_at_spi_socket_to_ref (GtkAtSpiSocket *self);
-void gtk_at_spi_socket_embed (GtkAtSpiSocket  *self,
-                              GDBusConnection *connection);
+G_DECLARE_FINAL_TYPE (ConstraintEditorApplication, constraint_editor_application, CONSTRAINT, EDITOR_APPLICATION, GtkApplication)
 
-G_END_DECLS
+ConstraintEditorApplication *constraint_editor_application_new (void);

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

@@ -0,0 +1,650 @@
+/*
+ * 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);
+
+  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

@@ -1,5 +1,5 @@
 /*
- * Copyright © 2016  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
@@ -13,26 +13,22 @@
  *
  * 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 <gdk/gdk.h>
-#include <gsk/gskrenderer.h>
+#include <gtk/gtk.h>
 
-G_BEGIN_DECLS
+#include "constraint-editor-application.h"
 
-#define GSK_TYPE_GPU_RENDERER (gsk_gpu_renderer_get_type ())
 
-#define GSK_GPU_RENDERER(obj)                 (G_TYPE_CHECK_INSTANCE_CAST ((obj), GSK_TYPE_GPU_RENDERER, GskGpuRenderer))
-#define GSK_IS_GPU_RENDERER(obj)              (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GSK_TYPE_GPU_RENDERER))
+#define CONSTRAINT_EDITOR_WINDOW_TYPE (constraint_editor_window_get_type ())
 
-typedef struct _GskGpuRenderer                GskGpuRenderer;
+G_DECLARE_FINAL_TYPE (ConstraintEditorWindow, constraint_editor_window, CONSTRAINT, EDITOR_WINDOW, GtkApplicationWindow)
 
-GDK_AVAILABLE_IN_ALL
-GType                   gsk_gpu_renderer_get_type            (void) G_GNUC_CONST;
-
-G_DEFINE_AUTOPTR_CLEANUP_FUNC(GskGpuRenderer, g_object_unref)
-
-G_END_DECLS
+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 +1,683 @@
+/*
+ * 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"
+
+G_GNUC_BEGIN_IGNORE_DEPRECATIONS
+
+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)
+{
+  int i;
+
+  gtk_combo_box_text_append (GTK_COMBO_BOX_TEXT (combo), "super", "Super");
+
+  if (model)
+    {
+      for (i = 0; i < g_list_model_get_n_items (model); i++)
+        {
+          GObject *item = g_list_model_get_object (model, i);
+          const char *name;
+
+          if (GTK_IS_CONSTRAINT (item))
+            continue;
+
+          name = get_target_name (GTK_CONSTRAINT_TARGET (item));
+
+          gtk_combo_box_text_append (GTK_COMBO_BOX_TEXT (combo), name, name);
+          g_object_unref (item);
+        }
+    }
+}
+
+static void
+constraint_attribute_combo (GtkWidget *combo,
+                            gboolean is_source)
+{
+  if (is_source)
+    gtk_combo_box_text_append (GTK_COMBO_BOX_TEXT (combo), "none", "None");
+  gtk_combo_box_text_append (GTK_COMBO_BOX_TEXT (combo), "left", "Left");
+  gtk_combo_box_text_append (GTK_COMBO_BOX_TEXT (combo), "right", "Right");
+  gtk_combo_box_text_append (GTK_COMBO_BOX_TEXT (combo), "top", "Top");
+  gtk_combo_box_text_append (GTK_COMBO_BOX_TEXT (combo), "bottom", "Bottom");
+  gtk_combo_box_text_append (GTK_COMBO_BOX_TEXT (combo), "start", "Start");
+  gtk_combo_box_text_append (GTK_COMBO_BOX_TEXT (combo), "end", "End");
+  gtk_combo_box_text_append (GTK_COMBO_BOX_TEXT (combo), "width", "Width");
+  gtk_combo_box_text_append (GTK_COMBO_BOX_TEXT (combo), "height", "Height");
+  gtk_combo_box_text_append (GTK_COMBO_BOX_TEXT (combo), "center-x", "Center X");
+  gtk_combo_box_text_append (GTK_COMBO_BOX_TEXT (combo), "center-y", "Center Y");
+  gtk_combo_box_text_append (GTK_COMBO_BOX_TEXT (combo), "baseline", "Baseline");
+}
+
+static void
+constraint_relation_combo (GtkWidget *combo)
+{
+  gtk_combo_box_text_append (GTK_COMBO_BOX_TEXT (combo), "le", "≤");
+  gtk_combo_box_text_append (GTK_COMBO_BOX_TEXT (combo), "eq", "=");
+  gtk_combo_box_text_append (GTK_COMBO_BOX_TEXT (combo), "ge", "≥");
+}
+
+static void
+constraint_strength_combo (GtkWidget *combo)
+{
+  gtk_combo_box_text_append (GTK_COMBO_BOX_TEXT (combo), "weak", "Weak");
+  gtk_combo_box_text_append (GTK_COMBO_BOX_TEXT (combo), "medium", "Medium");
+  gtk_combo_box_text_append (GTK_COMBO_BOX_TEXT (combo), "strong", "Strong");
+  gtk_combo_box_text_append (GTK_COMBO_BOX_TEXT (combo), "required", "Required");
+}
+
+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 GtkConstraintAttribute
+get_target_attr (const char *id)
+{
+  GtkConstraintAttribute attr;
+  GEnumClass *class = g_type_class_ref (GTK_TYPE_CONSTRAINT_ATTRIBUTE);
+  GEnumValue *value = g_enum_get_value_by_nick (class, id);
+  attr = value->value;
+  g_type_class_unref (class);
+
+  return attr;
+}
+
+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 (const char *id)
+{
+  GtkConstraintRelation relation;
+  GEnumClass *class = g_type_class_ref (GTK_TYPE_CONSTRAINT_RELATION);
+  GEnumValue *value = g_enum_get_value_by_nick (class, id);
+  relation = value->value;
+  g_type_class_unref (class);
+
+  return relation;
+}
+
+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 (const char *id)
+{
+  GtkConstraintStrength strength;
+  GEnumClass *class = g_type_class_ref (GTK_TYPE_CONSTRAINT_STRENGTH);
+  GEnumValue *value = g_enum_get_value_by_nick (class, id);
+  strength = value->value;
+  g_type_class_unref (class);
+
+  return strength;
+}
+
+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)
+{
+  const char *id;
+  gpointer target;
+  GtkConstraintAttribute target_attr;
+  gpointer source;
+  GtkConstraintAttribute source_attr;
+  GtkConstraintRelation relation;
+  double multiplier;
+  double constant;
+  int strength;
+  GtkConstraint *constraint;
+
+  id = gtk_combo_box_get_active_id (GTK_COMBO_BOX (editor->target));
+  target = get_target (editor->model, id);
+  id = gtk_combo_box_get_active_id (GTK_COMBO_BOX (editor->target_attr));
+  target_attr = get_target_attr (id);
+
+  id = gtk_combo_box_get_active_id (GTK_COMBO_BOX (editor->source));
+  source = get_target (editor->model, id);
+  id = gtk_combo_box_get_active_id (GTK_COMBO_BOX (editor->source_attr));
+  source_attr = get_target_attr (id);
+
+  id = gtk_combo_box_get_active_id (GTK_COMBO_BOX (editor->relation));
+  relation = get_relation (id);
+
+  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);
+
+  id = gtk_combo_box_get_active_id (GTK_COMBO_BOX (editor->strength));
+  strength = get_strength (id);
+
+  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)
+{
+  const char *id;
+
+  id = gtk_combo_box_get_active_id (GTK_COMBO_BOX (editor->source_attr));
+  if (strcmp (id, "none") == 0)
+    {
+      gtk_combo_box_set_active (GTK_COMBO_BOX (editor->source), -1);
+      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;
+  char *relation;
+  const char *multiplier;
+  const char *constant;
+  double c, m;
+
+  if (!editor->constructed)
+    return;
+
+  str = g_string_new ("");
+
+  name = gtk_combo_box_get_active_id (GTK_COMBO_BOX (editor->target));
+  attr = gtk_combo_box_get_active_id (GTK_COMBO_BOX (editor->target_attr));
+  relation = gtk_combo_box_text_get_active_text (GTK_COMBO_BOX_TEXT (editor->relation));
+
+  if (name == NULL)
+    name = "[ ]";
+
+  g_string_append_printf (str, "%s.%s %s ", name, attr, relation);
+  g_free (relation);
+
+  constant = gtk_editable_get_text (GTK_EDITABLE (editor->constant));
+  c = g_ascii_strtod (constant, NULL);
+
+  attr = gtk_combo_box_get_active_id (GTK_COMBO_BOX (editor->source_attr));
+  if (strcmp (attr, "none") != 0)
+    {
+      name = gtk_combo_box_get_active_id (GTK_COMBO_BOX (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)
+{
+  const char *target = gtk_combo_box_get_active_id (GTK_COMBO_BOX (editor->target));
+  const char *source = gtk_combo_box_get_active_id (GTK_COMBO_BOX (editor->source));
+  const char *source_attr = gtk_combo_box_get_active_id (GTK_COMBO_BOX (editor->source_attr));
+
+  if (target &&
+      (source || (source_attr && get_target_attr (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_attribute_combo (editor->target_attr, FALSE);
+  constraint_relation_combo (editor->relation);
+  constraint_target_combo (editor->model, editor->source, TRUE);
+  constraint_attribute_combo (editor->source_attr, TRUE);
+
+  constraint_strength_combo (editor->strength);
+
+  if (editor->constraint)
+    {
+      GtkConstraintTarget *target;
+      GtkConstraintAttribute attr;
+      GtkConstraintRelation relation;
+      GtkConstraintStrength strength;
+      const char *nick;
+      char *val;
+      double multiplier;
+      double constant;
+
+      target = gtk_constraint_get_target (editor->constraint);
+      nick = get_target_name (target);
+      gtk_combo_box_set_active_id (GTK_COMBO_BOX (editor->target), nick);
+
+      attr = gtk_constraint_get_target_attribute (editor->constraint);
+      nick = get_attr_nick (attr);
+      gtk_combo_box_set_active_id (GTK_COMBO_BOX (editor->target_attr), nick);
+
+      target = gtk_constraint_get_source (editor->constraint);
+      nick = get_target_name (target);
+      gtk_combo_box_set_active_id (GTK_COMBO_BOX (editor->source), nick);
+
+      attr = gtk_constraint_get_source_attribute (editor->constraint);
+      nick = get_attr_nick (attr);
+      gtk_combo_box_set_active_id (GTK_COMBO_BOX (editor->source_attr), nick);
+
+      relation = gtk_constraint_get_relation (editor->constraint);
+      nick = get_relation_nick (relation);
+      gtk_combo_box_set_active_id (GTK_COMBO_BOX (editor->relation), nick);
+
+      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);
+      nick = get_strength_nick (strength);
+      gtk_combo_box_set_active_id (GTK_COMBO_BOX (editor->strength), nick);
+
+      gtk_button_set_label (GTK_BUTTON (editor->button), "Apply");
+    }
+  else
+    {
+      gtk_combo_box_set_active_id (GTK_COMBO_BOX (editor->target_attr), "left");
+      gtk_combo_box_set_active_id (GTK_COMBO_BOX (editor->source_attr), "left");
+      gtk_combo_box_set_active_id (GTK_COMBO_BOX (editor->relation), "eq");
+      gtk_combo_box_set_active_id (GTK_COMBO_BOX (editor->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

@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2023 GNOME Foundation Inc.
+ * 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
@@ -14,22 +14,21 @@
  * 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: Alice Mikhaylenko <alicem@gnome.org>
+ * Authors: Matthias Clasen
  */
 
 #pragma once
 
-#include <gtk/css/gtkcss.h>
-#include "gtkcssvalueprivate.h"
-#include "gtkstylepropertyprivate.h"
-#include "css/gtkcssvariablevalueprivate.h"
+#include <gtk/gtk.h>
 
-G_BEGIN_DECLS
+#define CONSTRAINT_EDITOR_TYPE (constraint_editor_get_type ())
 
-GtkCssValue *_gtk_css_reference_value_new             (GtkStyleProperty    *property,
-                                                       GtkCssVariableValue *value,
-                                                       GFile               *file);
-void         _gtk_css_reference_value_set_subproperty (GtkCssValue         *value,
-                                                       guint                property);
+G_DECLARE_FINAL_TYPE (ConstraintEditor, constraint_editor, CONSTRAINT, EDITOR, GtkWidget)
 
-G_END_DECLS
+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 +1,167 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<interface>
+  <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="GtkComboBoxText" id="target">
+            <signal name="changed" handler="update_preview" swapped="yes"/>
+            <signal name="changed" handler="update_button" swapped="yes"/>
+            <layout>
+              <property name="column">1</property>
+              <property name="row">1</property>
+            </layout>
+          </object>
+        </child>
+        <child>
+          <object class="GtkComboBoxText" id="target_attr">
+            <signal name="changed" 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="GtkComboBoxText" id="relation">
+            <signal name="changed" handler="update_preview" swapped="yes"/>
+            <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="GtkComboBoxText" id="source">
+            <signal name="changed" handler="update_preview" swapped="yes"/>
+            <signal name="changed" handler="update_button" swapped="yes"/>
+            <layout>
+              <property name="column">1</property>
+              <property name="row">3</property>
+            </layout>
+          </object>
+        </child>
+        <child>
+          <object class="GtkComboBoxText" id="source_attr">
+            <signal name="changed" handler="update_preview" swapped="yes"/>
+            <signal name="changed" handler="source_attr_changed" swapped="yes"/>
+            <signal name="changed" 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="GtkComboBoxText" id="strength">
+            <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 +1,358 @@
+/*
+ * 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"
+
+G_GNUC_BEGIN_IGNORE_DEPRECATIONS
+
+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 void
+guide_strength_combo (GtkWidget *combo)
+{
+  gtk_combo_box_text_append (GTK_COMBO_BOX_TEXT (combo), "weak", "Weak");
+  gtk_combo_box_text_append (GTK_COMBO_BOX_TEXT (combo), "medium", "Medium");
+  gtk_combo_box_text_append (GTK_COMBO_BOX_TEXT (combo), "strong", "Strong");
+  gtk_combo_box_text_append (GTK_COMBO_BOX_TEXT (combo), "required", "Required");
+}
+
+static GtkConstraintStrength
+get_strength (const char *id)
+{
+  GtkConstraintStrength strength;
+  GEnumClass *class = g_type_class_ref (GTK_TYPE_CONSTRAINT_STRENGTH);
+  GEnumValue *value = g_enum_get_value_by_nick (class, id);
+  strength = value->value;
+  g_type_class_unref (class);
+
+  return strength;
+}
+
+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)
+{
+  const char *id;
+  int strength;
+  const char *name;
+  int w, h;
+  GtkConstraintGuide *guide;
+
+  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_combo_box_get_active_id (GTK_COMBO_BOX (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);
+
+  guide_strength_combo (editor->strength);
+
+  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);
+      nick = get_strength_nick (strength);
+      gtk_combo_box_set_active_id (GTK_COMBO_BOX (editor->strength), nick);
+
+      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_combo_box_set_active_id (GTK_COMBO_BOX (editor->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

@@ -0,0 +1,32 @@
+/*
+ * 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 GUIDE_EDITOR_TYPE (guide_editor_get_type ())
+
+G_DECLARE_FINAL_TYPE (GuideEditor, guide_editor, GUIDE, EDITOR, GtkWidget)
+
+GuideEditor * guide_editor_new (GtkConstraintGuide  *guide);
+
+void guide_editor_serialize_guide (GString            *str,
+                                   int                 indent,
+                                   GtkConstraintGuide *guide);

demos/constraint-editor/guide-editor.ui

@@ -0,0 +1,191 @@
+<?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="GtkComboBoxText" id="strength">
+            <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

@@ -1,8 +1,5 @@
-/* gtkatspi.h: AT-SPI
- *
- * Copyright 2024  Igalia S.L.
- *
- * SPDX-License-Identifier: LGPL-2.1-or-later
+/*
+ * 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
@@ -15,15 +12,17 @@
  * 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/>.
+ * 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 <gtk/gtk.h>
+#include <constraint-editor-application.h>
 
-#define __GTKATSPI_H_INSIDE__
-
-#include <gtk/a11y/gtkatspisocket.h>
-
-#undef __GTKATSPI_H_INSIDE__
+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/application.c

@@ -2,6 +2,8 @@
 
 #include <gtk/gtk.h>
 
+G_GNUC_BEGIN_IGNORE_DEPRECATIONS
+
 typedef GtkApplication DemoApplication;
 typedef GtkApplicationClass DemoApplicationClass;
 
@@ -35,7 +37,7 @@ show_action_dialog (GSimpleAction *action)
 {
   GtkAlertDialog *dialog;
 
-  dialog = gtk_alert_dialog_new ("You activated action: \"%s\"",
+  dialog = gtk_alert_dialog_new ("You activated action: \"%s\n",
                                  g_action_get_name (G_ACTION (action)));
   gtk_alert_dialog_show (dialog, NULL);
   g_object_unref (dialog);
@@ -214,41 +216,6 @@ activate_quit (GSimpleAction *action,
     }
 }
 
-static void
-delete_messages (gpointer data)
-{
-  g_list_free_full ((GList *)data, g_free);
-}
-
-static void
-pop_message (GtkWidget *status)
-{
-  GList *messages = (GList *) g_object_steal_data (G_OBJECT (status), "messages");
-
-  if (messages)
-    {
-      char *message = messages->data;
-      messages = g_list_remove (messages, message);
-
-      g_object_set_data_full (G_OBJECT (status), "messages",
-                              messages, delete_messages);
-
-      gtk_label_set_label (GTK_LABEL (status), message);
-    }
-}
-
-static void
-push_message (GtkWidget  *status,
-              const char *message)
-{
-  GList *messages = (GList *) g_object_steal_data (G_OBJECT (status), "messages");
-
-  gtk_label_set_label (GTK_LABEL (status), message);
-  messages = g_list_prepend (messages, g_strdup (message));
-  g_object_set_data_full (G_OBJECT (status), "messages",
-                          messages, delete_messages);
-}
-
 static void
 update_statusbar (GtkTextBuffer         *buffer,
                   DemoApplicationWindow *window)
@@ -259,7 +226,7 @@ update_statusbar (GtkTextBuffer         *buffer,
   GtkTextIter iter;
 
   /* clear any previous message, underflow is allowed */
-  pop_message (window->status);
+  gtk_statusbar_pop (GTK_STATUSBAR (window->status), 0);
 
   count = gtk_text_buffer_get_char_count (buffer);
 
@@ -273,7 +240,7 @@ update_statusbar (GtkTextBuffer         *buffer,
   msg = g_strdup_printf ("Cursor at row %d column %d - %d chars in document",
                          row, col, count);
 
-  push_message (window->status, msg);
+  gtk_statusbar_push (GTK_STATUSBAR (window->status), 0, msg);
 
   g_free (msg);
 }

demos/gtk-demo/application.ui

@@ -76,13 +76,8 @@
           </object>
         </child>
         <child>
-          <object class="GtkLabel" id="status">
+          <object class="GtkStatusbar" id="status">
             <property name="hexpand">1</property>
-            <property name="xalign">0</property>
-            <property name="margin-start">2</property>
-            <property name="margin-end">2</property>
-            <property name="margin-top">2</property>
-            <property name="margin-bottom">2</property>
             <layout>
               <property name="column">0</property>
               <property name="row">3</property>

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/bluroverlay.h

@@ -18,7 +18,8 @@
  * License along with this library. If not, see <http://www.gnu.org/licenses/>.
  */
 
-#pragma once
+#ifndef __BLUR_OVERLAY_H__
+#define __BLUR_OVERLAY_H__
 
 #include <gtk/gtk.h>
 
@@ -59,3 +60,5 @@ void       blur_overlay_set_child   (BlurOverlay *overlay,
                                      GtkWidget   *widget);
 
 G_END_DECLS
+
+#endif /* __BLUR_OVERLAY_H__ */

demos/gtk-demo/builder.c

@@ -1,5 +1,5 @@
 /* Builder
- * #Keywords: GMenu, GtkPopoverMenuBar, GtkBuilder, GtkShortcutController, toolbar
+ * #Keywords: GMenu, GtkPopoverMenuBar, GtkBuilder, GtkStatusBar, GtkShortcutController, toolbar
  *
  * Demonstrates a traditional interface, loaded from a XML description,
  * and shows how to connect actions to the menu items and toolbar buttons.
@@ -37,34 +37,30 @@ remove_timeout (gpointer data)
   g_source_remove (id);
 }
 
-static int
-pop_message (gpointer data)
+G_GNUC_BEGIN_IGNORE_DEPRECATIONS
+
+static gboolean
+pop_status (gpointer data)
 {
-  GtkWidget *status = data;
-
-  gtk_label_set_label (GTK_LABEL (status), "");
-  g_object_set_data (G_OBJECT (status), "timeout", GUINT_TO_POINTER (0));
-
+  gtk_statusbar_pop (GTK_STATUSBAR (data), 0);
+  g_object_set_data (G_OBJECT (data), "timeout", NULL);
   return G_SOURCE_REMOVE;
 }
 
 static void
-status_message (GtkWidget  *status,
-                const char *text)
+status_message (GtkStatusbar *status,
+                const char   *text)
 {
   guint id;
 
-  id = GPOINTER_TO_UINT (g_object_get_data (G_OBJECT (status), "timeout"));
-  if (id)
-    g_source_remove (id);
-
-  gtk_label_set_text (GTK_LABEL (status), text);
-
-  id = g_timeout_add (5000, pop_message, status);
+  gtk_statusbar_push (GTK_STATUSBAR (status), 0, text);
+  id = g_timeout_add (5000, pop_status, status);
 
   g_object_set_data_full (G_OBJECT (status), "timeout", GUINT_TO_POINTER (id), remove_timeout);
 }
 
+G_GNUC_END_IGNORE_DEPRECATIONS
+
 static void
 help_activate (GSimpleAction *action,
                GVariant      *parameter,
@@ -73,7 +69,7 @@ help_activate (GSimpleAction *action,
   GtkWidget *status;
 
   status = GTK_WIDGET (g_object_get_data (G_OBJECT (user_data), "status"));
-  status_message (status, "Help not available");
+  status_message (GTK_STATUSBAR (status), "Help not available");
 }
 
 static void
@@ -86,7 +82,7 @@ not_implemented (GSimpleAction *action,
 
   text = g_strdup_printf ("Action “%s” not implemented", g_action_get_name (G_ACTION (action)));
   status = GTK_WIDGET (g_object_get_data (G_OBJECT (user_data), "status"));
-  status_message (status, text);
+  status_message (GTK_STATUSBAR (status), text);
   g_free (text);
 }
 

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/css_basics.c

@@ -6,6 +6,8 @@
 
 #include <gtk/gtk.h>
 
+G_GNUC_BEGIN_IGNORE_DEPRECATIONS
+
 static void
 show_parsing_error (GtkCssProvider *provider,
                     GtkCssSection  *section,
@@ -47,23 +49,20 @@ css_text_changed (GtkTextBuffer  *buffer,
   gtk_text_buffer_remove_all_tags (buffer, &start, &end);
 
   text = gtk_text_buffer_get_text (buffer, &start, &end, FALSE);
-  gtk_css_provider_load_from_string (provider, text);
+  gtk_css_provider_load_from_data (provider, text, -1);
   g_free (text);
 }
 
-static void
-clear_provider (gpointer data)
-{
-  GtkStyleProvider *provider = data;
-
-  gtk_style_context_remove_provider_for_display (gdk_display_get_default (), provider);
-}
-
 static void
 apply_css (GtkWidget *widget, GtkStyleProvider *provider)
 {
-  gtk_style_context_add_provider_for_display (gdk_display_get_default (), provider, G_MAXUINT);
-  g_object_set_data_full (G_OBJECT (widget), "provider", provider, clear_provider);
+  GtkWidget *child;
+
+  gtk_style_context_add_provider (gtk_widget_get_style_context (widget), provider, G_MAXUINT);
+  for (child = gtk_widget_get_first_child (widget);
+       child != NULL;
+       child = gtk_widget_get_next_sibling (child))
+    apply_css (child, provider);
 }
 
 GtkWidget *
@@ -82,7 +81,6 @@ do_css_basics (GtkWidget *do_widget)
       gtk_window_set_title (GTK_WINDOW (window), "CSS Basics");
       gtk_window_set_transient_for (GTK_WINDOW (window), GTK_WINDOW (do_widget));
       gtk_window_set_default_size (GTK_WINDOW (window), 400, 300);
-      gtk_widget_add_css_class (window, "demo");
       g_object_add_weak_pointer (G_OBJECT (window), (gpointer *)&window);
 
       text = gtk_text_buffer_new (NULL);

demos/gtk-demo/css_basics.css

@@ -4,24 +4,23 @@
  * anymore. :)
  */
 
-/* This resets all properties to their defaults values
- * and overrides all user settings and the theme in use
- */
-@import url("resource://css_shadows/reset.css");
+/* This CSS resets all properties to their defaults values
+ *    and overrides all user settings and the theme in use */
+@import url("resource://css_basics/reset.css");
 
 /* Set a very futuristic style by default */
-.demo * {
+* {
   color: green;
   font-family: Monospace;
   border: 1px solid;
 }
 
-window.demo {
+window {
   background-color: white;
 }
 
 /* Make sure selections are visible */
-.demo selection {
+selection {
   background-color: darkGreen;
   color: black;
 }

demos/gtk-demo/css_multiplebgs.c

@@ -6,6 +6,8 @@
 
 #include <gtk/gtk.h>
 
+G_GNUC_BEGIN_IGNORE_DEPRECATIONS
+
 static void
 show_parsing_error (GtkCssProvider *provider,
                     GtkCssSection  *section,
@@ -48,23 +50,33 @@ css_text_changed (GtkTextBuffer  *buffer,
   gtk_text_buffer_remove_all_tags (buffer, &start, &end);
 
   text = gtk_text_buffer_get_text (buffer, &start, &end, FALSE);
-  gtk_css_provider_load_from_string (provider, text);
+  gtk_css_provider_load_from_data (provider, text, -1);
   g_free (text);
 }
 
 static void
-clear_provider (gpointer data)
+drawing_area_draw (GtkDrawingArea *da,
+                   cairo_t        *cr,
+                   int             width,
+                   int             height,
+                   gpointer        data)
 {
-  GtkStyleProvider *provider = data;
+  GtkStyleContext *context = gtk_widget_get_style_context (GTK_WIDGET (da));
 
-  gtk_style_context_remove_provider_for_display (gdk_display_get_default (), provider);
+  gtk_render_background (context, cr, 0, 0, width, height);
+  gtk_render_frame (context, cr, 0, 0, width, height);
 }
 
 static void
 apply_css (GtkWidget *widget, GtkStyleProvider *provider)
 {
-  gtk_style_context_add_provider_for_display (gdk_display_get_default (), provider, G_MAXUINT);
-  g_object_set_data_full (G_OBJECT (widget), "provider", provider, clear_provider);
+  GtkWidget *child;
+
+  gtk_style_context_add_provider (gtk_widget_get_style_context (widget), provider, G_MAXUINT);
+  for (child = gtk_widget_get_first_child (widget);
+       child != NULL;
+       child = gtk_widget_get_next_sibling (child))
+    apply_css (child, provider);
 }
 
 GtkWidget *
@@ -83,17 +95,16 @@ do_css_multiplebgs (GtkWidget *do_widget)
       gtk_window_set_title (GTK_WINDOW (window), "Multiple Backgrounds");
       gtk_window_set_transient_for (GTK_WINDOW (window), GTK_WINDOW (do_widget));
       gtk_window_set_default_size (GTK_WINDOW (window), 400, 300);
-      gtk_widget_add_css_class (window, "demo");
       g_object_add_weak_pointer (G_OBJECT (window), (gpointer *)&window);
 
       overlay = gtk_overlay_new ();
       gtk_window_set_child (GTK_WINDOW (window), overlay);
 
       child = gtk_drawing_area_new ();
-      /* Don't set a draw_func, since we are only interested in CSS drawing,
-       * which happens automatically.
-       */
       gtk_widget_set_name (child, "canvas");
+      gtk_drawing_area_set_draw_func (GTK_DRAWING_AREA (child),
+                                      drawing_area_draw,
+                                      NULL, NULL);
       gtk_overlay_set_child (GTK_OVERLAY (overlay), child);
 
       child = gtk_button_new ();

demos/gtk-demo/css_pixbufs.c

@@ -7,6 +7,8 @@
 
 #include <gtk/gtk.h>
 
+G_GNUC_BEGIN_IGNORE_DEPRECATIONS
+
 static void
 show_parsing_error (GtkCssProvider *provider,
                     GtkCssSection  *section,
@@ -49,23 +51,20 @@ css_text_changed (GtkTextBuffer  *buffer,
   gtk_text_buffer_remove_all_tags (buffer, &start, &end);
 
   text = gtk_text_buffer_get_text (buffer, &start, &end, FALSE);
-  gtk_css_provider_load_from_string (provider, text);
+  gtk_css_provider_load_from_data (provider, text, -1);
   g_free (text);
 }
 
-static void
-clear_provider (gpointer data)
-{
-  GtkStyleProvider *provider = data;
-
-  gtk_style_context_remove_provider_for_display (gdk_display_get_default (), provider);
-}
-
 static void
 apply_css (GtkWidget *widget, GtkStyleProvider *provider)
 {
-  gtk_style_context_add_provider_for_display (gdk_display_get_default (), provider, G_MAXUINT);
-  g_object_set_data_full (G_OBJECT (widget), "provider", provider, clear_provider);
+  GtkWidget *child;
+
+  gtk_style_context_add_provider (gtk_widget_get_style_context (widget), provider, G_MAXUINT);
+  for (child = gtk_widget_get_first_child (widget);
+       child != NULL;
+       child = gtk_widget_get_next_sibling (child))
+    apply_css (child, provider);
 }
 
 GtkWidget *
@@ -84,7 +83,6 @@ do_css_pixbufs (GtkWidget *do_widget)
       gtk_window_set_title (GTK_WINDOW (window), "Animated Backgrounds");
       gtk_window_set_transient_for (GTK_WINDOW (window), GTK_WINDOW (do_widget));
       gtk_window_set_default_size (GTK_WINDOW (window), 400, 300);
-      gtk_widget_add_css_class (window, "demo");
       g_object_add_weak_pointer (G_OBJECT (window), (gpointer *)&window);
 
       paned = gtk_paned_new (GTK_ORIENTATION_VERTICAL);

demos/gtk-demo/css_pixbufs.css

@@ -50,7 +50,7 @@
     100% { background-size: 12px, 96px, 12px, 96px, 12px, 96px, 12px, 96px, auto; }
 }
 
-window.demo {
+window {
     background-image: url("resource://css_pixbufs/images/apple-red.png"),
                       url("resource://css_pixbufs/images/gnome-applets.png"),
                       url("resource://css_pixbufs/images/gnome-calendar.png"),
@@ -66,11 +66,11 @@ window.demo {
 }
 
 /* Make the text editor has a nice style */
-window.demo .view, scrollbar, separator {
+.view, scrollbar, separator {
   color: black;
   background-color: rgba(255,255,255,0.5);
 }
 
-window.demo .view:selected {
+.view:selected {
   background-color: rgba(127,127,255,0.5);
 }

demos/gtk-demo/css_shadows.c

@@ -5,6 +5,8 @@
 
 #include <gtk/gtk.h>
 
+G_GNUC_BEGIN_IGNORE_DEPRECATIONS
+
 static void
 show_parsing_error (GtkCssProvider *provider,
                     GtkCssSection  *section,
@@ -46,23 +48,20 @@ css_text_changed (GtkTextBuffer  *buffer,
   gtk_text_buffer_remove_all_tags (buffer, &start, &end);
 
   text = gtk_text_buffer_get_text (buffer, &start, &end, FALSE);
-  gtk_css_provider_load_from_string (provider, text);
+  gtk_css_provider_load_from_data (provider, text, -1);
   g_free (text);
 }
 
-static void
-clear_provider (gpointer data)
-{
-  GtkStyleProvider *provider = data;
-
-  gtk_style_context_remove_provider_for_display (gdk_display_get_default (), provider);
-}
-
 static void
 apply_css (GtkWidget *widget, GtkStyleProvider *provider)
 {
-  gtk_style_context_add_provider_for_display (gdk_display_get_default (), provider, G_MAXUINT);
-  g_object_set_data_full (G_OBJECT (widget), "provider", provider, clear_provider);
+  GtkWidget *child;
+
+  gtk_style_context_add_provider (gtk_widget_get_style_context (widget), provider, G_MAXUINT);
+  for (child = gtk_widget_get_first_child (widget);
+       child != NULL;
+       child = gtk_widget_get_next_sibling (child))
+    apply_css (child, provider);
 }
 
 static GtkWidget *
@@ -102,7 +101,6 @@ do_css_shadows (GtkWidget *do_widget)
       gtk_window_set_title (GTK_WINDOW (window), "Shadows");
       gtk_window_set_transient_for (GTK_WINDOW (window), GTK_WINDOW (do_widget));
       gtk_window_set_default_size (GTK_WINDOW (window), 400, 300);
-      gtk_widget_add_css_class (window, "demo");
       g_object_add_weak_pointer (G_OBJECT (window), (gpointer *)&window);
 
       paned = gtk_paned_new (GTK_ORIENTATION_VERTICAL);
@@ -144,7 +142,7 @@ do_css_shadows (GtkWidget *do_widget)
     }
 
   if (!gtk_widget_get_visible (window))
-    gtk_window_present (GTK_WINDOW (window));
+    gtk_widget_set_visible (window, TRUE);
   else
     gtk_window_destroy (GTK_WINDOW (window));
 

demos/gtk-demo/css_shadows.css

@@ -5,13 +5,12 @@
  */
 
 /* This CSS resets all properties to their defaults values
- * and overrides all user settings and the theme in use
- */
+ *    and overrides all user settings and the theme in use */
 @import url("resource://css_shadows/reset.css");
 @import url("resource://css_shadows/cssview.css");
 
 /* Get a nice background for the window */
-window.demo.background {
+.background {
   background-color: #4870bc;
   background-image: linear-gradient(to left, transparent, rgba(255,255,255,.07) 50%, transparent 50%),
                     linear-gradient(to left, transparent, rgba(255,255,255,.13) 50%, transparent 50%),
@@ -20,7 +19,7 @@ window.demo.background {
   background-size: 29px, 59px, 73px, 109px;
 }
 
-window.demo button {
+button {
   color: black;
   padding: 10px;
   border-radius: 5px;
@@ -28,15 +27,18 @@ window.demo button {
   border: 1px transparent solid;
 }
 
-window.demo button:hover {
+button:hover {
   text-shadow: 3px 3px 5px alpha(black, 0.75);
   -gtk-icon-shadow: 3px 3px 5px alpha(black, 0.75);
   box-shadow: 3px 3px 5px alpha(black, 0.5) inset;
   border: solid 1px alpha(black, 0.75);
 }
 
-window.demo button:active {
+button:active {
   padding: 11px 9px 9px 11px;
   text-shadow: 1px 1px 2.5px alpha(black, 0.6);
   -gtk-icon-shadow: 1px 1px 2.5px alpha(black, 0.6);
 }
+
+
+

demos/gtk-demo/cssview.css

@@ -1,21 +1,21 @@
 /* Make the text editor has a nice style */
-window.demo .view {
+.view {
   color: #2e3436;
   font-family: Monospace;
   background-color: alpha(white, 0.30);
 }
 
-window.demo .view:selected {
+.view:selected {
   color: white;
   background-color: #4a90d9;
 }
 
-window.demo scrollbar trough,
+scrollbar trough,
 .scrollbars-junction {
   background-color: alpha(white, 0.80);
 }
 
-window.demo scrollbar slider {
+scrollbar slider {
   border-width: 3px;
   border-style: solid;
   border-radius: 10px;
@@ -24,11 +24,11 @@ window.demo scrollbar slider {
   background-color: #999;
 }
 
-window.demo scrollbar slider:hover {
+scrollbar slider:hover {
   background-color: #555;
 }
 
-window.demo paned separator {
+paned separator {
   background-color: alpha(white, 0.80);
   background-image: linear-gradient(transparent, transparent 1px, #999 1px, #999 4px, transparent 4px);
   background-size: 40px auto;
@@ -36,6 +36,6 @@ window.demo paned separator {
   background-position: center;
 }
 
-window.demo paned separator:hover {
+paned separator:hover {
   background-image: linear-gradient(transparent, transparent 1px, #555 1px, #555 4px, transparent 4px);
 }

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/curve-editor.h

@@ -0,0 +1,36 @@
+#pragma once
+
+#include <gtk/gtk.h>
+
+G_BEGIN_DECLS
+
+#define CURVE_TYPE_EDITOR (curve_editor_get_type ())
+G_DECLARE_FINAL_TYPE (CurveEditor, curve_editor, CURVE, EDITOR, GtkWidget)
+
+GtkWidget *       curve_editor_new              (void);
+
+void              curve_editor_set_edit         (CurveEditor *self,
+                                                 gboolean     edit);
+
+void              curve_editor_set_path         (CurveEditor *self,
+                                                 GskPath     *path);
+
+GskPath *         curve_editor_get_path         (CurveEditor *self);
+
+void              curve_editor_set_stroke       (CurveEditor *self,
+                                                 GskStroke   *stroke);
+
+const GskStroke * curve_editor_get_stroke       (CurveEditor *self);
+
+
+void              curve_editor_set_color        (CurveEditor   *self,
+                                                 const GdkRGBA *color);
+
+const GdkRGBA *   curve_editor_get_color        (CurveEditor *self);
+
+gboolean          curve_editor_get_show_outline (CurveEditor *self);
+
+void              curve_editor_set_show_outline (CurveEditor *self,
+                                                 gboolean     show_outline);
+
+G_END_DECLS

demos/gtk-demo/curve.c

@@ -0,0 +1,269 @@
+/* Path/Curve Editor
+ *
+ * This demo shows an elaborate curve editor that you would expect to find
+ * in a vector graphics editor. It is built on top of GTK's path APIs.
+ */
+
+#include <gtk/gtk.h>
+#include "curve-editor.h"
+
+
+static GskPath *
+make_circle_path (void)
+{
+  float w = 310;
+  float h = 310;
+  float cx = w / 2;
+  float cy = h / 2;
+  float pad = 20;
+  float r = (w - 2 * pad) / 2;
+  float k = 0.55228;
+  float kr = k  * r;
+  GskPathBuilder *builder;
+
+  builder = gsk_path_builder_new ();
+
+  gsk_path_builder_move_to (builder,  cx, pad);
+  gsk_path_builder_cubic_to (builder, cx + kr, pad,
+                                      w - pad, cy - kr,
+                                      w - pad, cy);
+  gsk_path_builder_cubic_to (builder, w - pad, cy + kr,
+                                      cx + kr, h - pad,
+                                      cx, h - pad);
+  gsk_path_builder_cubic_to (builder, cx - kr, h - pad,
+                                      pad, cy + kr,
+                                      pad, cy);
+  gsk_path_builder_cubic_to (builder, pad, cy - kr,
+                                      cx - kr, pad,
+                                      cx, pad);
+  gsk_path_builder_close (builder);
+
+  return gsk_path_builder_free_to_path (builder);
+}
+
+static void
+edit_changed (GtkToggleButton *button,
+              GParamSpec      *pspec,
+              CurveEditor     *editor)
+{
+  curve_editor_set_edit (editor, gtk_toggle_button_get_active (button));
+}
+
+static void
+reset (GtkButton   *button,
+       CurveEditor *editor)
+{
+  GskPath *path;
+
+  path = make_circle_path ();
+  curve_editor_set_path (editor, path);
+  gsk_path_unref (path);
+}
+
+static void
+line_width_changed (GtkSpinButton *spin,
+                    CurveEditor   *editor)
+{
+  GskStroke *stroke;
+
+  stroke = gsk_stroke_copy (curve_editor_get_stroke (editor));
+  gsk_stroke_set_line_width (stroke, gtk_spin_button_get_value (spin));
+  curve_editor_set_stroke (editor, stroke);
+  gsk_stroke_free (stroke);
+}
+
+static void
+cap_changed (GtkDropDown *combo,
+             GParamSpec  *pspec,
+             CurveEditor *editor)
+{
+  GskStroke *stroke;
+
+  stroke = gsk_stroke_copy (curve_editor_get_stroke (editor));
+  gsk_stroke_set_line_cap (stroke, (GskLineCap)gtk_drop_down_get_selected (combo));
+  curve_editor_set_stroke (editor, stroke);
+  gsk_stroke_free (stroke);
+}
+
+static void
+join_changed (GtkDropDown *combo,
+              GParamSpec  *pspec,
+              CurveEditor *editor)
+{
+  GskStroke *stroke;
+
+  stroke = gsk_stroke_copy (curve_editor_get_stroke (editor));
+  gsk_stroke_set_line_join (stroke, (GskLineJoin)gtk_drop_down_get_selected (combo));
+  curve_editor_set_stroke (editor, stroke);
+  gsk_stroke_free (stroke);
+}
+
+static void
+color_changed (GtkColorDialogButton *button,
+               GParamSpec           *pspec,
+               CurveEditor          *editor)
+{
+  curve_editor_set_color (editor, gtk_color_dialog_button_get_rgba (button));
+}
+
+static void
+stroke_toggled (GtkCheckButton *button,
+                CurveEditor    *editor)
+{
+  curve_editor_set_show_outline (editor, gtk_check_button_get_active (button));
+  gtk_widget_queue_draw (GTK_WIDGET (editor));
+}
+
+static void
+limit_changed (GtkSpinButton *spin,
+               CurveEditor   *editor)
+{
+  GskStroke *stroke;
+
+  stroke = gsk_stroke_copy (curve_editor_get_stroke (editor));
+  gsk_stroke_set_miter_limit (stroke, gtk_spin_button_get_value (spin));
+  curve_editor_set_stroke (editor, stroke);
+  gsk_stroke_free (stroke);
+}
+
+static void
+dashes_changed (GtkEntry    *entry,
+                GParamSpec  *spec,
+                CurveEditor *editor)
+{
+  const char *text;
+  char **split;
+  GArray *dash;
+  GskStroke *stroke;
+
+  text = gtk_editable_get_text (GTK_EDITABLE (entry));
+  split = g_strsplit (text, " ", 0);
+
+  dash = g_array_new (FALSE, FALSE, sizeof (float));
+  for (int i = 0; split[i] != NULL; i++)
+    {
+      double d;
+      char *endp = 0;
+
+      d = g_strtod (split[i], &endp);
+      if (*endp == '\0')
+        g_array_append_vals (dash, (float[1]) { d }, 1);
+    }
+
+  g_strfreev (split);
+
+  stroke = gsk_stroke_copy (curve_editor_get_stroke (editor));
+  gsk_stroke_set_dash (stroke, (const float *)dash->data, dash->len);
+  curve_editor_set_stroke (editor, stroke);
+  gsk_stroke_free (stroke);
+
+  g_array_free (dash, TRUE);
+}
+
+GtkWidget *
+do_curve (GtkWidget *do_widget)
+{
+  static GtkWidget *window = NULL;
+  GtkWidget *demo;
+  GtkWidget *edit_toggle;
+  GtkWidget *reset_button;
+  GtkWidget *titlebar;
+  GtkWidget *stroke_toggle;
+  GtkWidget *line_width_spin;
+  GtkWidget *stroke_button;
+  GtkWidget *popover;
+  GtkWidget *grid;
+  GtkWidget *cap_combo;
+  GtkWidget *join_combo;
+  GtkWidget *color_button;
+  GtkWidget *limit_spin;
+  GtkWidget *dash_entry;
+
+  if (!window)
+    {
+      window = gtk_window_new ();
+      gtk_window_set_title (GTK_WINDOW (window), "Curve Editor");
+      g_object_add_weak_pointer (G_OBJECT (window), (gpointer *)&window);
+      gtk_window_set_default_size (GTK_WINDOW (window), 315, 350);
+
+      edit_toggle = gtk_toggle_button_new ();
+      gtk_button_set_icon_name (GTK_BUTTON (edit_toggle), "document-edit-symbolic");
+
+      reset_button = gtk_button_new_from_icon_name ("edit-undo-symbolic");
+
+      stroke_button = gtk_menu_button_new ();
+      gtk_menu_button_set_icon_name (GTK_MENU_BUTTON (stroke_button), "open-menu-symbolic");
+      popover = gtk_popover_new ();
+      gtk_menu_button_set_popover (GTK_MENU_BUTTON (stroke_button), popover);
+
+      grid = gtk_grid_new ();
+      gtk_grid_set_row_spacing (GTK_GRID (grid), 6);
+      gtk_grid_set_column_spacing (GTK_GRID (grid), 6);
+      gtk_popover_set_child (GTK_POPOVER (popover), grid);
+
+      gtk_grid_attach (GTK_GRID (grid), gtk_label_new ("Color:"), 0, 0, 1, 1);
+      color_button = gtk_color_dialog_button_new (gtk_color_dialog_new ());
+      gtk_grid_attach (GTK_GRID (grid), color_button, 1, 0, 1, 1);
+
+      gtk_grid_attach (GTK_GRID (grid), gtk_label_new ("Line width:"), 0, 1, 1, 1);
+      line_width_spin = gtk_spin_button_new_with_range (1, 20, 1);
+      gtk_spin_button_set_value (GTK_SPIN_BUTTON (line_width_spin), 1);
+      gtk_grid_attach (GTK_GRID (grid), line_width_spin, 1, 1, 1, 1);
+
+      gtk_grid_attach (GTK_GRID (grid), gtk_label_new ("Line cap:"), 0, 2, 1, 1);
+      cap_combo = gtk_drop_down_new_from_strings ((const char *[]){"Butt", "Round", "Square", NULL});
+      gtk_grid_attach (GTK_GRID (grid), cap_combo, 1, 2, 1, 1);
+
+      gtk_grid_attach (GTK_GRID (grid), gtk_label_new ("Line join:"), 0, 3, 1, 1);
+      join_combo = gtk_drop_down_new_from_strings ((const char *[]){"Miter", "Miter-clip", "Round", "Bevel", "Arcs", NULL});
+      gtk_grid_attach (GTK_GRID (grid), join_combo, 1, 3, 1, 1);
+
+      gtk_grid_attach (GTK_GRID (grid), gtk_label_new ("Miter limit:"), 0, 4, 1, 1);
+      limit_spin = gtk_spin_button_new_with_range (0, 10, 1);
+      gtk_spin_button_set_digits (GTK_SPIN_BUTTON (limit_spin), 1);
+      gtk_spin_button_set_value (GTK_SPIN_BUTTON (limit_spin), 4);
+      gtk_grid_attach (GTK_GRID (grid), limit_spin, 1, 4, 1, 1);
+
+      gtk_grid_attach (GTK_GRID (grid), gtk_label_new ("Dashes:"), 0, 5, 1, 1);
+      dash_entry = gtk_entry_new ();
+      gtk_grid_attach (GTK_GRID (grid), dash_entry, 1, 5, 1, 1);
+
+      stroke_toggle = gtk_check_button_new_with_label ("Show outline");
+      gtk_grid_attach (GTK_GRID (grid), stroke_toggle, 1, 6, 1, 1);
+
+      titlebar = gtk_header_bar_new ();
+      gtk_header_bar_pack_start (GTK_HEADER_BAR (titlebar), edit_toggle);
+      gtk_header_bar_pack_start (GTK_HEADER_BAR (titlebar), reset_button);
+      gtk_header_bar_pack_start (GTK_HEADER_BAR (titlebar), stroke_button);
+
+      gtk_window_set_titlebar (GTK_WINDOW (window), titlebar);
+
+      demo = curve_editor_new ();
+
+      g_signal_connect (stroke_toggle, "toggled", G_CALLBACK (stroke_toggled), demo);
+      g_signal_connect (edit_toggle, "notify::active", G_CALLBACK (edit_changed), demo);
+      g_signal_connect (reset_button, "clicked", G_CALLBACK (reset), demo);
+      g_signal_connect (cap_combo, "notify::selected", G_CALLBACK (cap_changed), demo);
+      g_signal_connect (join_combo, "notify::selected", G_CALLBACK (join_changed), demo);
+      g_signal_connect (color_button, "notify::rgba", G_CALLBACK (color_changed), demo);
+      g_signal_connect (line_width_spin, "value-changed", G_CALLBACK (line_width_changed), demo);
+      g_signal_connect (limit_spin, "value-changed", G_CALLBACK (limit_changed), demo);
+      g_signal_connect (dash_entry, "notify::text", G_CALLBACK (dashes_changed), demo);
+
+      reset (NULL, CURVE_EDITOR (demo));
+
+      gtk_spin_button_set_value (GTK_SPIN_BUTTON (line_width_spin), 6);
+      gtk_color_dialog_button_set_rgba (GTK_COLOR_DIALOG_BUTTON (color_button), &(GdkRGBA) { 1, 0, 0, 1 });
+      gtk_drop_down_set_selected (GTK_DROP_DOWN (cap_combo), GSK_LINE_CAP_ROUND);
+      gtk_editable_set_text (GTK_EDITABLE (dash_entry), "0 8");
+
+      gtk_window_set_child (GTK_WINDOW (window), demo);
+    }
+
+  if (!gtk_widget_get_visible (window))
+    gtk_window_present (GTK_WINDOW (window));
+  else
+    gtk_window_destroy (GTK_WINDOW (window));
+
+  return window;
+}

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>
@@ -245,6 +259,10 @@
   <gresource prefix="/video-player">
     <file>bbb.png</file>
   </gresource>
+  <gresource prefix="/curve">
+    <file>curve-editor.c</file>
+    <file>curve-editor.h</file>
+  </gresource>
   <gresource prefix="/sources">
     <file>application_demo.c</file>
     <file>assistant.c</file>
@@ -262,6 +280,7 @@
     <file>css_pixbufs.c</file>
     <file>css_shadows.c</file>
     <file>cursors.c</file>
+    <file>curve.c</file>
     <file>dialog.c</file>
     <file>drawingarea.c</file>
     <file>dnd.c</file>
@@ -281,6 +300,7 @@
     <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>
@@ -323,8 +343,6 @@
     <file>password_entry.c</file>
     <file>path_fill.c</file>
     <file>path_maze.c</file>
-    <file>path_spinner.c</file>
-    <file>path_walk.c</file>
     <file>path_text.c</file>
     <file>peg_solitaire.c</file>
     <file>pickers.c</file>
@@ -411,10 +429,6 @@
   <gresource prefix="/fontrendering">
     <file>fontrendering.ui</file>
   </gresource>
-  <gresource prefix="/path_walk">
-    <file>path_walk.ui</file>
-    <file compressed="true">path_world.txt</file>
-  </gresource>
   <gresource prefix="/path_text">
     <file>path_text.ui</file>
   </gresource>
@@ -438,10 +452,6 @@
     <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/demo.ui

@@ -208,13 +208,7 @@
           </object>
         </child>
         <child>
-          <object class="GtkLabel" id="statusbar1">
-            <property name="xalign">0</property>
-            <property name="margin-start">2</property>
-            <property name="margin-end">2</property>
-            <property name="margin-top">2</property>
-            <property name="margin-bottom">2</property>
-          </object>
+          <object class="GtkStatusbar" id="statusbar1"/>
         </child>
       </object>
     </child>

demos/gtk-demo/demo3widget.c

@@ -75,9 +75,7 @@ query_tooltip (GtkWidget  *widget,
   gtk_grid_attach (GTK_GRID (grid), label, 0, 2, 1, 1);
 
   precision = 1;
-  s = NULL;
   do {
-    g_free (s);
     s = g_strdup_printf ("%.*f", precision, self->scale);
     l = strlen (s) - 1;
     while (s[l] == '0')

demos/gtk-demo/demotaggedentry.h

@@ -18,7 +18,8 @@
  * License along with this library. If not, see <http://www.gnu.org/licenses/>.
  */
 
-#pragma once
+#ifndef __DEMO_TAGGED_ENTRY_H__
+#define __DEMO_TAGGED_ENTRY_H__
 
 #include <gtk/gtk.h>
 
@@ -56,3 +57,5 @@ void            demo_tagged_entry_tag_set_has_close_button (DemoTaggedEntryTag *
                                                             gboolean            has_close_button);
 
 G_END_DECLS
+
+#endif /* __DEMO_TAGGED_ENTRY_H__ */

demos/gtk-demo/demowidget.c

@@ -34,7 +34,7 @@ transition (GtkWidget     *widget,
 {
   DemoWidget *self = DEMO_WIDGET (widget);
   DemoLayout *demo_layout = DEMO_LAYOUT (gtk_widget_get_layout_manager (widget));
-  gint64 now = gdk_frame_clock_get_frame_time (frame_clock);
+  gint64 now = g_get_monotonic_time ();
 
   gtk_widget_queue_allocate (widget);
 
@@ -66,13 +66,11 @@ clicked (GtkGestureClick *gesture,
          gpointer         data)
 {
   DemoWidget *self = data;
-  GdkFrameClock *frame_clock;
 
   if (self->tick_id != 0)
     return;
 
-  frame_clock = gtk_widget_get_frame_clock (GTK_WIDGET (self));
-  self->start_time = gdk_frame_clock_get_frame_time (frame_clock);
+  self->start_time = g_get_monotonic_time ();
   self->tick_id = gtk_widget_add_tick_callback (GTK_WIDGET (self), transition, NULL, NULL);
 }
 

demos/gtk-demo/dnd.c

@@ -162,39 +162,27 @@ click_done (GtkGesture *gesture)
     gtk_widget_insert_after (item, canvas, last_child);
 }
 
-/* GtkSettings treats `GTK_THEME=foo:dark` as theme name `foo`, variant `dark`,
- * and our embedded CSS files let `foo-dark` work as an alias for `foo:dark`. */
-static gboolean
-has_dark_suffix (const char *theme)
-{
-  return g_str_has_suffix (theme, ":dark") ||
-         g_str_has_suffix (theme, "-dark");
-}
-
-/* So we can make a good guess whether the current theme is dark by checking for
- * either: it is suffixed `[:-]dark`, or Settings:…prefer-dark-theme is TRUE. */
 static gboolean
 theme_is_dark (void)
 {
-  const char *env_theme;
   GtkSettings *settings;
   char *theme;
   gboolean prefer_dark;
   gboolean dark;
 
-  /* Like GtkSettings, 1st see if theme is overridden by environment variable */
-  env_theme = g_getenv ("GTK_THEME");
-  if (env_theme != NULL)
-    return has_dark_suffix (env_theme);
-
-  /* If not, test Settings:…theme-name in the same way OR :…prefer-dark-theme */
   settings = gtk_settings_get_default ();
   g_object_get (settings,
                 "gtk-theme-name", &theme,
                 "gtk-application-prefer-dark-theme", &prefer_dark,
                 NULL);
-  dark = prefer_dark || has_dark_suffix (theme);
+
+  if ((strcmp (theme, "Adwaita") == 0 && prefer_dark) || strcmp (theme, "HighContrastInverse") == 0)
+    dark = TRUE;
+  else
+    dark = FALSE;
+
   g_free (theme);
+
   return dark;
 }
 
@@ -760,7 +748,9 @@ do_dnd (GtkWidget *do_widget)
       GtkCssProvider *provider;
       GString *css;
 
-      button = gtk_color_dialog_button_new (gtk_color_dialog_new ());
+G_GNUC_BEGIN_IGNORE_DEPRECATIONS
+      button = gtk_color_button_new ();
+G_GNUC_END_IGNORE_DEPRECATIONS
       g_object_unref (g_object_ref_sink (button));
 
       provider = gtk_css_provider_new ();

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/expander.c

@@ -10,6 +10,8 @@
 #include <glib/gi18n.h>
 #include <gtk/gtk.h>
 
+G_GNUC_BEGIN_IGNORE_DEPRECATIONS
+
 static GtkWidget *window = NULL;
 
 static void
@@ -43,22 +45,21 @@ do_expander (GtkWidget *do_widget)
   if (!window)
     {
       toplevel = GTK_WIDGET (gtk_widget_get_root (do_widget));
-      window = gtk_window_new ();
-      gtk_window_set_title (GTK_WINDOW (window), "Expander");
-      gtk_window_set_transient_for (GTK_WINDOW (window), GTK_WINDOW (toplevel));
-      area = gtk_box_new (GTK_ORIENTATION_VERTICAL, 10);
-      gtk_widget_set_margin_start (area, 10);
-      gtk_widget_set_margin_end (area, 10);
-      gtk_widget_set_margin_top (area, 10);
-      gtk_widget_set_margin_bottom (area, 10);
-      gtk_window_set_child (GTK_WINDOW (window), area);
-      label = gtk_label_new ("<big><b>Something went wrong</b></big>");
-      gtk_label_set_use_markup (GTK_LABEL (label), TRUE);
-      gtk_box_append (GTK_BOX (area), label);
-      label = gtk_label_new ("Here are some more details but not the full story");
+      window = gtk_message_dialog_new_with_markup (GTK_WINDOW (toplevel),
+                                                   0,
+                                                   GTK_MESSAGE_ERROR,
+                                                   GTK_BUTTONS_CLOSE,
+                                                   "<big><b>%s</b></big>",
+                                                   "Something went wrong");
+      gtk_message_dialog_format_secondary_text (GTK_MESSAGE_DIALOG (window),
+                                                "Here are some more details "
+                                                "but not the full story.");
+
+      area = gtk_message_dialog_get_message_area (GTK_MESSAGE_DIALOG (window));
+
+      label = gtk_widget_get_last_child (area);
       gtk_label_set_wrap (GTK_LABEL (label), FALSE);
       gtk_widget_set_vexpand (label, FALSE);
-      gtk_box_append (GTK_BOX (area), label);
 
       expander = gtk_expander_new ("Details:");
       gtk_widget_set_vexpand (expander, TRUE);
@@ -121,7 +122,7 @@ do_expander (GtkWidget *do_widget)
   }
 
   if (!gtk_widget_get_visible (window))
-    gtk_window_present (GTK_WINDOW (window));
+    gtk_widget_set_visible (window, TRUE);
   else
     gtk_window_destroy (GTK_WINDOW (window));
 

demos/gtk-demo/fishbowl.c

@@ -9,6 +9,7 @@
 
 #include "gtkfishbowl.h"
 #include "gtkgears.h"
+#include "gskshaderpaintable.h"
 
 #include "nodewidget.h"
 #include "graphwidget.h"
@@ -70,11 +71,13 @@ create_blurred_button (void)
   return w;
 }
 
+G_GNUC_BEGIN_IGNORE_DEPRECATIONS
 static GtkWidget *
 create_font_button (void)
 {
-  return gtk_font_dialog_button_new (gtk_font_dialog_new ());
+  return gtk_font_button_new ();
 }
+G_GNUC_END_IGNORE_DEPRECATIONS
 
 static GtkWidget *
 create_level_bar (void)
@@ -151,6 +154,38 @@ 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 void
 mapped (GtkWidget *w)
 {
@@ -185,40 +220,36 @@ create_graph (void)
 
 static const struct {
   const char *name;
-  GtkWidget * (* create_func) (void);
-  gboolean    (* check) (GtkFishbowl *fb);
+  GtkWidget * (*create_func) (void);
 } widget_types[] = {
-  { "Icon",       create_icon,           NULL },
-  { "Button",     create_button,         NULL },
-  { "Blurbutton", create_blurred_button, NULL },
-  { "Fontbutton", create_font_button,    NULL },
-  { "Levelbar",   create_level_bar,      NULL },
-  { "Label",      create_label,          NULL },
-  { "Spinner",    create_spinner,        NULL },
-  { "Spinbutton", create_spinbutton,     NULL },
-  { "Video",      create_video,          NULL },
-  { "Gears",      create_gears,          NULL },
-  { "Switch",     create_switch,         NULL },
-  { "Menubutton", create_menu_button,    NULL },
-  { "Tiger",      create_tiger,          NULL },
-  { "Graph",      create_graph,          NULL },
+  { "Icon",       create_icon           },
+  { "Button",     create_button         },
+  { "Blurbutton", create_blurred_button },
+  { "Fontbutton", create_font_button    },
+  { "Levelbar",   create_level_bar      },
+  { "Label",      create_label          },
+  { "Spinner",    create_spinner        },
+  { "Spinbutton", create_spinbutton     },
+  { "Video",      create_video          },
+  { "Gears",      create_gears          },
+  { "Switch",     create_switch         },
+  { "Menubutton", create_menu_button    },
+  { "Shader",     create_cogs           },
+  { "Tiger",      create_tiger          },
+  { "Graph",      create_graph          },
 };
 
 static int selected_widget_type = -1;
 static const int N_WIDGET_TYPES = G_N_ELEMENTS (widget_types);
 
-static gboolean
+static void
 set_widget_type (GtkFishbowl *fishbowl,
                  int          widget_type_index)
 {
   GtkWidget *window;
 
   if (widget_type_index == selected_widget_type)
-    return TRUE;
-
-  if (widget_types[widget_type_index].check != NULL &&
-      !widget_types[widget_type_index].check (fishbowl))
-    return FALSE;
+    return;
 
   selected_widget_type = widget_type_index;
 
@@ -228,8 +259,6 @@ set_widget_type (GtkFishbowl *fishbowl,
   window = GTK_WIDGET (gtk_widget_get_root (GTK_WIDGET (fishbowl)));
   gtk_window_set_title (GTK_WINDOW (window),
                         widget_types[selected_widget_type].name);
-
-  return TRUE;
 }
 
 G_MODULE_EXPORT void
@@ -237,17 +266,14 @@ fishbowl_next_button_clicked_cb (GtkButton *source,
                                  gpointer   user_data)
 {
   GtkFishbowl *fishbowl = user_data;
-  int new_index = selected_widget_type;
+  int new_index;
 
-  do
-    {
-      if (new_index + 1 >= N_WIDGET_TYPES)
-        new_index = 0;
-      else
-        new_index = new_index + 1;
+  if (selected_widget_type + 1 >= N_WIDGET_TYPES)
+    new_index = 0;
+  else
+    new_index = selected_widget_type + 1;
 
-    }
-  while (!set_widget_type (fishbowl, new_index));
+  set_widget_type (fishbowl, new_index);
 }
 
 G_MODULE_EXPORT void
@@ -255,18 +281,14 @@ fishbowl_prev_button_clicked_cb (GtkButton *source,
                                  gpointer   user_data)
 {
   GtkFishbowl *fishbowl = user_data;
-  int new_index = selected_widget_type;
+  int new_index;
 
-  do
-    {
-      if (new_index - 1 < 0)
-        new_index = N_WIDGET_TYPES - 1;
-      else
-        new_index = new_index - 1;
+  if (selected_widget_type - 1 < 0)
+    new_index = N_WIDGET_TYPES - 1;
+  else
+    new_index = selected_widget_type - 1;
 
-    }
-
-  while (!set_widget_type (fishbowl, new_index));
+  set_widget_type (fishbowl, new_index);
 }
 
 G_MODULE_EXPORT void
@@ -305,20 +327,11 @@ do_fishbowl (GtkWidget *do_widget)
   if (!window)
     {
       GtkBuilder *builder;
-      GtkBuilderScope *scope;
       GtkWidget *bowl;
 
       g_type_ensure (GTK_TYPE_FISHBOWL);
 
-      scope = gtk_builder_cscope_new ();
-      gtk_builder_cscope_add_callback (GTK_BUILDER_CSCOPE (scope), fishbowl_prev_button_clicked_cb);
-      gtk_builder_cscope_add_callback (GTK_BUILDER_CSCOPE (scope), fishbowl_next_button_clicked_cb);
-      gtk_builder_cscope_add_callback (GTK_BUILDER_CSCOPE (scope), fishbowl_changes_toggled_cb);
-      gtk_builder_cscope_add_callback (GTK_BUILDER_CSCOPE (scope), format_header_cb);
-
-      builder = gtk_builder_new ();
-      gtk_builder_set_scope (builder, scope);
-      gtk_builder_add_from_resource (builder, "/fishbowl/fishbowl.ui", NULL);
+      builder = gtk_builder_new_from_resource ("/fishbowl/fishbowl.ui");
       window = GTK_WIDGET (gtk_builder_get_object (builder, "window"));
       g_object_add_weak_pointer (G_OBJECT (window), (gpointer *)&window);
 
@@ -330,7 +343,6 @@ do_fishbowl (GtkWidget *do_widget)
 
       gtk_widget_realize (window);
       g_object_unref (builder);
-      g_object_unref (scope);
     }
 
   if (!gtk_widget_get_visible (window))

demos/gtk-demo/font_features.c

@@ -600,8 +600,8 @@ update_display (void)
   if (s->len > 0)
     {
       pango_font_description_set_variations (desc, s->str);
+      g_string_free (s, TRUE);
     }
-  g_string_free (s, TRUE);
 
   font_desc = pango_font_description_to_string (desc);
 
@@ -1586,7 +1586,7 @@ update_font_variations (void)
         }
 
       gtk_grid_attach (GTK_GRID (demo->variations_grid), combo, 1, -1, 3, 1);
-      g_signal_connect (combo, "notify::selected", G_CALLBACK (instance_changed), NULL);
+      g_signal_connect (combo, "notify::selecte", G_CALLBACK (instance_changed), NULL);
       demo->instance_combo = combo;
    }
 

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

@@ -15,7 +15,8 @@
  * License along with this library. If not, see <http://www.gnu.org/licenses/>.
  */
 
-#pragma once
+#ifndef __GTK_FONT_PLANE_H__
+#define __GTK_FONT_PLANE_H__
 
 #include <gtk/gtk.h>
 
@@ -55,7 +56,9 @@ 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
+
+#endif /* __GTK_FONT_PLANE_H__ */

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/graphwidget.c

@@ -7,6 +7,7 @@ struct _GraphWidget
   GskPath *path;
   GskStroke *stroke;
   GdkRGBA color;
+  GskPath *stroke_path;
 
   guint tick_cb;
   guint64 start_time;
@@ -30,6 +31,7 @@ update_path (GraphWidget *self,
   GskPathBuilder *builder;
 
   g_clear_pointer (&self->path, gsk_path_unref);
+  g_clear_pointer (&self->stroke_path, gsk_path_unref);
 
   for (int i = 0; i < 20; i++)
     {
@@ -55,6 +57,7 @@ update_path (GraphWidget *self,
                                p[i+3].x, p[i+3].y);
 
   self->path = gsk_path_builder_free_to_path (builder);
+  self->stroke_path = gsk_path_stroke (self->path, self->stroke);
 }
 
 static gboolean
@@ -103,7 +106,7 @@ graph_widget_dispose (GObject *object)
 {
   GraphWidget *self = GRAPH_WIDGET (object);
 
-  g_clear_pointer (&self->path, gsk_path_unref);
+  gsk_path_unref (self->path);
   gsk_stroke_free (self->stroke);
 
   G_OBJECT_CLASS (graph_widget_parent_class)->dispose (object);
@@ -114,8 +117,16 @@ graph_widget_snapshot (GtkWidget   *widget,
                       GtkSnapshot *snapshot)
 {
   GraphWidget *self = GRAPH_WIDGET (widget);
+  int width, height;
 
-  gtk_snapshot_append_stroke (snapshot, self->path, self->stroke, &self->color);
+  width = gtk_widget_get_width (widget);
+  height = gtk_widget_get_height (widget);
+
+  gtk_snapshot_push_fill (snapshot, self->stroke_path, GSK_FILL_RULE_WINDING);
+  gtk_snapshot_append_color (snapshot,
+                             &self->color,
+                             &GRAPHENE_RECT_INIT (0, 0, width, height));
+  gtk_snapshot_pop (snapshot);
 }
 
 static void

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 +1,46 @@
+/*
+ * 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>
+ */
+
+#ifndef __GSK_SHADER_PAINTABLE_H__
+#define __GSK_SHADER_PAINTABLE_H__
+
+#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
+
+#endif /* __GSK_SHADER_PAINTABLE_H__ */

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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-       id="path6978"
-       d="M 22.94243,82.287118 L 20.88413,30.82696 L 53.816977,55.527708 L 53.816977,111.10486 L 22.94243,82.287118 z"
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-       d="M 53.816977,111.10486 L 103.21619,90.5207 L 107.33282,39.060543 L 53.816977,55.527708 L 53.816977,111.10486 z"
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-       sodipodi:nodetypes="ccc"
-       id="path6982"
-       d="M 23.216626,81.319479 L 70.48573,67.361442 L 103.38422,90.444516"
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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

@@ -15,7 +15,8 @@
  * License along with this library. If not, see <http://www.gnu.org/licenses/>.
  */
 
-#pragma once
+#ifndef __GTK_FISHBOWL_H__
+#define __GTK_FISHBOWL_H__
 
 #include <gtk/gtk.h>
 
@@ -55,7 +56,7 @@ 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,
@@ -64,3 +65,5 @@ void       gtk_fishbowl_set_creation_func (GtkFishbowl       *fishbowl,
                                            GtkFishCreationFunc creation_func);
 
 G_END_DECLS
+
+#endif /* __GTK_FISHBOWL_H__ */

demos/gtk-demo/gtkgears.c

@@ -840,24 +840,24 @@ gtk_gears_unrealize (GtkWidget *widget)
   GtkGearsPrivate *priv = gtk_gears_get_instance_private ((GtkGears *) widget);
 
   gtk_gl_area_make_current (glarea);
-  if (gtk_gl_area_get_error (glarea) == NULL)
-    {
-      /* Release the resources associated with OpenGL */
-      if (priv->gear_vbo[0] != 0)
-        glDeleteBuffers (1, &(priv->gear_vbo[0]));
+  if (gtk_gl_area_get_error (glarea) != NULL)
+    return;
 
-      if (priv->gear_vbo[1] != 0)
-        glDeleteBuffers (1, &(priv->gear_vbo[1]));
+  /* Release the resources associated with OpenGL */
+  if (priv->gear_vbo[0] != 0)
+    glDeleteBuffers (1, &(priv->gear_vbo[0]));
 
-      if (priv->gear_vbo[2] != 0)
-        glDeleteBuffers (1, &(priv->gear_vbo[2]));
+  if (priv->gear_vbo[1] != 0)
+    glDeleteBuffers (1, &(priv->gear_vbo[1]));
 
-      if (priv->vao != 0)
-        glDeleteVertexArrays (1, &priv->vao);
+  if (priv->gear_vbo[2] != 0)
+    glDeleteBuffers (1, &(priv->gear_vbo[2]));
 
-      if (priv->program != 0)
-        glDeleteProgram (priv->program);
-    }
+  if (priv->vao != 0)
+    glDeleteVertexArrays (1, &priv->vao);
+
+  if (priv->program != 0)
+    glDeleteProgram (priv->program);
 
   priv->ModelViewProjectionMatrix_location = 0;
   priv->NormalMatrix_location = 0;

demos/gtk-demo/gtkgears.h

@@ -1,4 +1,5 @@
-#pragma once
+#ifndef __GTK_GEARS_H__
+#define __GTK_GEARS_H__
 
 #include <gtk/gtk.h>
 
@@ -43,3 +44,5 @@ void       gtk_gears_set_fps_label (GtkGears *gears,
 
 
 G_END_DECLS
+
+#endif /* __GTK_GEARS_H__ */

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 +1,23 @@
+#ifndef __GTK_SHADER_BIN_H__
+#define __GTK_SHADER_BIN_H__
+
+#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
+
+#endif /* __GTK_SHADER_BIN_H__ */