Colors of Noise

Entries tagged "librem5".

GTK+ and the application id
28th August 2018

tl;dr: If you want to be sure your application will be displayed with the correct icon under different Wayland compositors make sure that your GApplication (or GtkApplication) uses


on GTK+3. On GTK+4 this is handled for you.

Details: While working on touch based window switching for the Librem5 I noticed that lots of the GNOME application did not end up with a proper icon when using g_desktop_app_info_new (desktop_id). The desktop_id is determined from the Wayland xdg surface's app_id as specified by in Wayland's xdg-shell protocol.

The protocol says:

The compositor shell will try to group application surfaces together
by their app ID. As a best practice, it is suggested to select app
ID's that match the basename of the application's .desktop file.
For example, "org.freedesktop.FooViewer" where the .desktop file is

It's even more explicit about the relation of the app_id to the D-Bus service name:

For D-Bus activatable applications, the app ID is used as the D-Bus
service name.

So why does this currently fail? It's because GTK+3 historically uses g_get_prgname() to set the app_id and this defaults to application's basename. But what we rather want is

g_application_id == D-Bus service name == $(basename desktop_file_path .desktop) == xdg app_id

There were patches by Jonas Ådahl to fix this but those were partially reverted since it broke existing applications. Now with GTK+4 around the corner we can fix this. See the migration docs.

This will also allow us to get rid of all the rename-desktop-file in the flatpak manifests too.

(The reason why this currently works in gnome-shell is because there's a private protocoll between GTK+ and GNOME Shell that (among other things) works around this).

Update: to check what app_id Wayland is seeing use:

WAYLAND_DEBUG=1 your_program |& grep 'xdg_toplevel@[0-9]\+\.set_app_id'
Tags: librem5, phosh, planetdebian, planetgnome.
libhandy 0.0.2
24th July 2018

Last month we tagged the first release of libhandy, a GTK+ library to ease the development of GNOME applications for mobile devices and small screens. Two of the contained widgets, HdyLeaflet and HdyColumn, are containers to address the specific size constraints of phones (video by Adrien). The rest are special purpose widgets, needed more than once on mobile devices, e.g. a Keypad (video).

This time around for the v0.0.2 release we mostly have bugfixes. From the Debian package's changelog:

[ Adrien Plazas ]
* dialer: Make the grid visible and forbid show all.
* example: Drop usage of show_all()
* dialer: Add column-spacing and row-spacing props.
* example: Change the grid's spacing and minimum size request.
* flatpak: Allow access to the dconf config dir.
* Replace phone-dial-symbolic by call-start-symbolic.
* column: Fix height for width request.

[ Guido Günther ]
* Use instead of
* Add AUTHORS file
* gitlab-ci: Build on Debian buster using provided build-deps.
* arrows: test object construction
* Multiple gtk-doc fixes
* docs: Abort on warnings.
* DialerButton: free letters

The Debian package was uploaded to Debian's NEW queue.

Tags: librem5, planetdebian, planetgnome.

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