[PATCH v2] xdg-shell: use case to change the app ID at runtime

[glogow at fbihome.de]

From: Jan-Marek Glogowski <glogow at fbihome.de>

LibreOffice is one big binary with explicit brandings for different
application modules. This is represented in X11 by a different
WM_CLASS setting for a window. The WM_CLASS is changed based on the
loaded document at runtime. As a result LibreOfiice already offers
multiple desktop files with different icons, StartupWMClass
entries and application names.

This amendment of the set_app_id request just explicitly specifies
the use case to change a surfaces' app ID at runtime, so a compositor
implementor is made aware of it. Just as the WM_CLASS, a change of
the app ID should result in an update of the propertes of a surface
depending on the app ID, like the window icon specified in the
desktop file or a re-grouping of the surfaces in a task manager.
---
 stable/xdg-shell/xdg-shell.xml | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/stable/xdg-shell/xdg-shell.xml b/stable/xdg-shell/xdg-shell.xml
index 2e420c6..145b39e 100644
--- a/stable/xdg-shell/xdg-shell.xml
+++ b/stable/xdg-shell/xdg-shell.xml
@@ -604,6 +604,10 @@
 	For example, "org.freedesktop.FooViewer" where the .desktop file is
 	"org.freedesktop.FooViewer.desktop".
 
+	The request can be used to change the app ID of a surface at runtime,
+	which should be handled by a compositor by updating the grouping and
+	other properties depending on the ID.
+
 	See the desktop-entry specification [0] for more details on
 	application identifiers and how they relate to well-known D-Bus
 	names and .desktop files.
-- 
2.20.1