wayland: Add API for disabling the event dispatching

This allows the integration of Clutter with another library, like GTK+,
that is dispatching the events itself. This is implemented by calling
into the cogl_wayland_renderer_set_event_dispatch_enabled() and since
that function must be called on the newly created renderer the newly
added clutter_wayland_disable_event_retrieval must be called before
clutter_init()

https://bugzilla.gnome.org/show_bug.cgi?id=704279

clutter/clutter.symbols

@@ -1598,6 +1598,7 @@ clutter_wayland_input_device_get_wl_seat
 clutter_wayland_stage_get_wl_shell_surface
 clutter_wayland_stage_get_wl_surface
 clutter_wayland_set_display
+clutter_wayland_disable_event_retrieval
 #endif
 #ifdef CLUTTER_WINDOWING_WIN32
 clutter_win32_disable_event_retrieval

clutter/wayland/clutter-backend-wayland.c

@@ -61,6 +61,7 @@
 G_DEFINE_TYPE (ClutterBackendWayland, clutter_backend_wayland, CLUTTER_TYPE_BACKEND);
 
 static struct wl_display *_foreign_display = NULL;
+static gboolean _no_event_dispatch = FALSE;
 
 static void clutter_backend_wayland_load_cursor (ClutterBackendWayland *backend_wayland);
 
@@ -240,6 +241,7 @@ clutter_backend_wayland_get_renderer (ClutterBackend  *backend,
 
   renderer = cogl_renderer_new ();
 
+  cogl_wayland_renderer_set_event_dispatch_enabled (renderer, !_no_event_dispatch);
   cogl_renderer_set_winsys_id (renderer, COGL_WINSYS_ID_EGL_WAYLAND);
 
   cogl_wayland_renderer_set_foreign_display (renderer,
@@ -352,3 +354,32 @@ clutter_wayland_set_display (struct wl_display *display)
 
   _foreign_display = display;
 }
+
+/**
+ * clutter_wayland_disable_event_retrieval:
+ *
+ * Disables the dispatch of the events in the main loop.
+ *
+ * This is useful for integrating Clutter with another library that will do the
+ * event dispatch; in general only a single source should be acting on changes
+ * on the Wayland file descriptor.
+ *
+ * <warning>This function can only be called before calling
+ * clutter_init().</warning>
+ *
+ * This function should not be normally used by applications.
+ *
+ * Since: 1.16
+ */
+void
+clutter_wayland_disable_event_retrieval (void)
+{
+  if (_clutter_context_is_initialized ())
+    {
+      g_warning ("%s() can only be used before calling clutter_init()",
+                 G_STRFUNC);
+      return;
+    }
+
+  _no_event_dispatch = TRUE;
+}

clutter/wayland/clutter-wayland.h

@@ -52,5 +52,8 @@ struct wl_surface *clutter_wayland_stage_get_wl_surface (ClutterStage *stage);
 CLUTTER_AVAILABLE_IN_1_16
 void clutter_wayland_set_display (struct wl_display *display);
 
+CLUTTER_AVAILABLE_IN_1_16
+void clutter_wayland_disable_event_retrieval (void);
+
 G_END_DECLS
 #endif /* __CLUTTER_WAYLAND_H__ */

doc/reference/clutter/clutter-sections.txt

@@ -1436,6 +1436,7 @@ clutter_wayland_input_device_get_wl_seat
 clutter_wayland_stage_get_wl_shell_surface
 clutter_wayland_stage_get_wl_surface
 clutter_wayland_set_display
+clutter_wayland_disable_event_retrieval
 </SECTION>
 
 <SECTION>