API: Deprecate key snooping

You really shouldn't be doing this. If you have to, you can use
gdk_window_add_filter() or listen to raw events on XI2.

gtk/gtkmain.c

@@ -2142,6 +2142,9 @@ gtk_device_grab_remove (GtkWidget *widget,
  *
  * Returns: a unique id for this key snooper for use with
  *    gtk_key_snooper_remove().
+ *
+ * Deprecated: 3.4: Key snooping should not be done. Events should
+ *     be handled by widgets.
  */
 guint
 gtk_key_snooper_install (GtkKeySnoopFunc snooper,
@@ -2166,6 +2169,9 @@ gtk_key_snooper_install (GtkKeySnoopFunc snooper,
  * @snooper_handler_id: Identifies the key snooper to remove
  *
  * Removes the key snooper function with the given id.
+ *
+ * Deprecated: 3.4: Key snooping should not be done. Events should
+ *     be handled by widgets.
  */
 void
 gtk_key_snooper_remove (guint snooper_id)

gtk/gtkmain.h

@@ -152,8 +152,10 @@ void       gtk_device_grab_add     (GtkWidget          *widget,
 void       gtk_device_grab_remove  (GtkWidget          *widget,
                                     GdkDevice          *device);
 
+G_GNUC_DEPRECATED
 guint      gtk_key_snooper_install (GtkKeySnoopFunc snooper,
                                     gpointer        func_data);
+G_GNUC_DEPRECATED
 void       gtk_key_snooper_remove  (guint           snooper_handler_id);
 
 GdkEvent * gtk_get_current_event        (void);