f916d82280
Upon joining the a11y tree. And do so recursively, as long as the parent
is also not a widget.
As for the explanation, please grab a mug of your favorite drink. It's
a little complicated.
GTK realizes AT contexts in 3 situations:
1. When it's a toplevel, it's realized unconditionally
2. When the widget is focused
3. When the accessible is appended to a realized parent
Most importantly, GTK lazily realizes accessibles, and does not realize
child accessibles recursively.
Clearly, conditions 1 and 2 only ever happen for GtkWidgets, which are
accessible objects themselves. These two conditions will handle the vast
majority of cases of apps and platform libraries.
However, there are non-widget accessibles out there. GTK itself offers a
non-widget accessible implementation - GtkAtspiSocket - which is used by
WebKitGTK.
Now, let's look at WebKitGTK use case. It'll demonstrate the problem
nicely.
WebKitGTK creates the GtkAtspiSocket object *after* loading most of the
page. At this point, there are 2 possibilities:
1. The web view widget is focused. In this case, the AT context of the
web view is realized, and GTK will realize the GtkAtspiSocket when
it is added to the a11y tree (condition 3 above).
2. The web view widget is *not* focused. At some point the user focuses
the web view, and GTK will realize the AT context of the web view.
But remember, GTK does not realize child accessibles! That means
GtkAtspiSocket won't be realized.
This example demonstrates a general problem with non-widget accessibles:
non-widget accessibles cannot trigger conditions 1 and 2, so they're
never realized. The only way they're realized in if they happen to be
added to an already realized accessible (condition 3).
To fix that, the following is proposed: always realize non-widget
accessibles, and also of their non-widget accessible parents. This is
not ideal, of course, as it might generate some D-Bus chattery, but GTK
does not have enough information to realize these objects at more
appropriate times.
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 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:
- xrandr
- xrender
- xi
- xext
- xfixes
- xcursor
- xdamage
- xcomposite
Once you have all the necessary dependencies, you can build GTK by using Meson:
$ meson setup _build
$ meson compile -C_build
You can run the test suite using:
$ meson test -C_build
And, finally, you can install GTK using:
$ sudo meson install -C_build
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