GTK+

GTK+ is a multi platform toolkit for creating graphical user interfaces. It has a large range of widgets available for the user all driven through a centralised theme system.

The GTK+ backend is under active continuous development - currently you should only attempt to use it if you are experienced with GTK+.

Getting the source

For correct functionality with current Wayland you must use the GTK+ master branch. As a precursor to these steps you must have downloaded and compiled Wayland as per the building instructions.

GTK+ master also currently depends on an unstable release version of glib and atk. To avoid problems it is advisable to install this into the prefix used in the Wayland build instructions.

$ git clone git://git.gnome.org/glib
$ git clone git://git.gnome.org/atk
$ git clone git://git.gnome.org/gtk+

Compiling GTK+ and its dependencies

This section depends on the environment variables defined in the build instructions being set.

glib

$ ./autogen.sh --prefix=$WLD
$ make && make install

atk

$ ./autogen.sh --prefix=$WLD
$ make && make install

gtk

$ ./autogen.sh --prefix=$WLD --enable-wayland-backend
$ make && make install

The configure scripts may report some missing packages. Install these from source or from your distribution.

Trying it out

The GTK+ source tree includes some test programs that you can run to check functionality. If you have configured with multiple backends then you should make sure to set the following environment variable.

export GDK_BACKEND=wayland

Inside the tests tests directory are some standalone test programs for various pieces of widget functionality. A more comprehensive tool for testing is demo/gtk-demo/gtk3-demo which provides a UI for selecting various widgets to play with. The screenshot below shows what the demo application looks like.

Porting your GTK+ application

The GTK+ port to Wayland has some major functionality gaps. Porting of applications at this stage should simply be to start identifying where applications makes API calls that will not function under Wayland.

• Ensure that your application uses gtk+-3.0 for its pkg-config request.
• All calls to the gdk_x11_ namespace and raw Xlib calls must be wrapped in both build-time and run-time backend checks.
• Check the errata below for issues that might affect your application.

Known issues

• Client side decorations are available in the the master branch but not in 3.8 or older.
• Copy and paste functionality is implemented however there may be certain cases that do not work - please report these in the bug tracking system
• Drag and drop is not implemented.
• Popup menus appear but may not have the correct grab behavior and are not positioned in the correct location.

Lots more details including plans and progress can be found on the GNOME wiki.

Getting help and reporting issues

Try the #gtk+ IRC channel on irc.gimp.org or if you've found a bug you can report it in GNOME Bugzilla.