[glib: 1/2] docs: Improved documentation of GNotification

[Philip Withnall <pwithnall src gnome org>]

commit e727a69a8bd6a8cecee7b753d88716b4c5e040e7
Author: Nitin Wartkar <nitinwartkar58 gmail com>
Date:   Mon May 17 10:30:54 2021 +0000

    docs: Improved documentation of GNotification

 gio/gnotification.c | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)
---
diff --git a/gio/gnotification.c b/gio/gnotification.c
index 27efed3f4..aa7df7f7b 100644
--- a/gio/gnotification.c
+++ b/gio/gnotification.c
@@ -43,6 +43,29 @@
  * not running, applications using #GNotification should be able to be
  * started as a D-Bus service, using #GApplication.
  *
+ * In order for #GNotification to work, the application must have installed
+ * a `.desktop` file. For example:
+ * |[
+ *  [Desktop Entry]
+ *   Name=Test Application
+ *   Comment=Description of what Test Application does
+ *   Exec=gnome-test-application
+ *   Icon=org.gnome.TestApplication
+ *   Terminal=false
+ *   Type=Application
+ *   Categories=GNOME;GTK;TestApplication Category;
+ *   StartupNotify=true
+ *   DBusActivatable=true
+ *   X-GNOME-UsesNotifications=true
+ * ]|
+ *
+ * The `X-GNOME-UsesNotifications` key indicates to GNOME Control Center
+ * that this application uses notifications, so it can be listed in the
+ * Control Center’s ‘Notifications’ panel.
+ *
+ * The `.desktop` file must be named as `org.gnome.TestApplication.desktop`,
+ * where `org.gnome.TestApplication` is the ID passed to g_application_new().
+ *
  * User interaction with a notification (either the default action, or
  * buttons) must be associated with actions on the application (ie:
  * "app." actions).  It is not possible to route user interaction