If we are querying the best supported pixel format for our HDC via wglChoosePixelFormatARB() (i.e. we have the WGL_ARB_pixel_format extension), it may return a pixel format that is different from the pixel format that we used for the dummy context that we have setup, in order to, well, run wglChoosePixelFormatARB(), which sadly requires a WGL context (HGLRC) to be current in order to use it, which means the dummy HDC already has a pixel format that has been set (notice that each HDC is only allowed to have its pixel format to be set *once*). This is notably the case on Intel display drivers. Since we are emulating surfaceless GL contexts, we are using the dummy GL context (and thus dummy HDC that is derived from the notification HWND used in GdkWin32Display) for doing that, we would get into trouble if th actual HDC from the GdkWin32Surface has a different pixel format set. So, as a result, in order to fix this situation, we do the following: * Create yet another dummy HWND in order to grab the HDC to query for the capabilities the GL drivers support, and to call wglChoosePixelFormatARB() as appropriate (or ChoosePixelFormat()) for the final pixel format that we use. * Ditch the dummy GL context, HDC and HWND after obtaining the pixel format. * Then set the final pixel format that we obtained onto the HDC that is derived from the HWND used in GdkWin32Display for notifications, which will become our new dummy HDC. * Create a new dummy HGLRC for use with the new dummy HDC to emulate surfaceless GL support.
GTK — The GTK toolkit
General information
GTK is a multi-platform toolkit for creating graphical user interfaces. Offering a complete set of widgets, GTK is suitable for projects ranging from small one-off projects to complete application suites.
GTK is a free and open-source software project. The licensing terms for GTK, the GNU LGPL, allow it to be used by all developers, including those developing proprietary software, without any license fees or royalties.
GTK is hosted by the GNOME project (thanks!) and used by a wide variety of applications and projects.
The official download location
The official web site
The official developers blog
Discussion forum
Nightly documentation can be found at
- Gtk: https://gnome.pages.gitlab.gnome.org/gtk/gtk4/
- Gdk: https://gnome.pages.gitlab.gnome.org/gtk/gdk4/
- Gsk: https://gnome.pages.gitlab.gnome.org/gtk/gsk4/
Nightly flatpaks of our demos can be installed from the GNOME 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:
You will also need various dependencies, based on the platform you are building for:
If you are building the X11 backend, you will also need:
- Xlib, and the following X extensions:
- xrandr
- xrender
- xi
- xext
- xfixes
- xcursor
- 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:
$ meson _build .
$ cd _build
$ ninja
You can run the test suite using:
$ meson test
And, finally, you can install GTK using:
$ sudo ninja install
Complete information about installing GTK and related libraries can be found in the file:
docs/reference/gtk/html/gtk-building.html
Or online
Building from git
The GTK sources are hosted on gitlab.gnome.org. The main
development branch is called main
, and stable branches are named after their minor
version, for example gtk-4-10
.
How to report bugs
Bugs should be reported on the issues page.
In the bug report please include:
-
Information about your system. For instance:
- which version of GTK you are using
- what operating system and version
- for Linux, which distribution
- if you built GTK, the list of options used to configure the build
And anything else you think is relevant.
-
How to reproduce the bug.
If you can reproduce it with one of the demo applications that are built in the demos/ subdirectory, on one of the test programs that are built in the tests/ subdirectory, that will be most convenient. Otherwise, please include a short test program that exhibits the behavior. As a last resort, you can also provide a pointer to a larger piece of software that can be downloaded.
-
If the bug was a crash, the exact text that was printed out when the crash occurred.
-
Further information such as stack traces may be useful, but is not necessary.
Contributing to GTK
Please, follow the contribution guide to know how to start contributing to GTK.
If you want to support GTK financially, please consider donating to the GNOME project, which runs the infrastructure hosting GTK.
Release notes
The release notes for GTK are part of the migration guide in the API reference. See:
Licensing terms
GTK is released under the terms of the GNU Lesser General Public License, version 2.1 or, at your option, any later version, as published by the Free Software Foundation.
Please, see the COPYING
file for further information.
GTK includes a small number of source files under the Apache license:
- A fork of the roaring bitmaps implementation in gtk/roaring
- An adaptation of timsort from python in gtk/timsort