xdg-shell: Clarify the meaning of app ID and give example

Signed-off-by: Jonas Ådahl <jadahl@gmail.com>

diff --git a/protocol/xdg-shell.xml b/protocol/xdg-shell.xml
index 1629bd0..0720662 100644 (file)
--- a/protocol/xdg-shell.xml
+++ b/protocol/xdg-shell.xml
@@ -189,6 +189,15 @@
        the surface belongs. The compositor can use this to group multiple
        surfaces together, or to determine how to launch a new application.
 
+       For D-Bus activatable applications, the app ID is used as the D-Bus
+       service name.
+
+       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
+       "org.freedesktop.FooViewer.desktop".
+
        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.