compositor: Drop get_stage_for_display helper

As one can get that from the backend/compositor directly.
Expose the necessary functions to allow doing so.

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/4131>

src/compositor/compositor-private.h

@@ -66,12 +66,7 @@ gboolean meta_compositor_is_unredirect_inhibited (MetaCompositor *compositor);
 
 MetaDisplay * meta_compositor_get_display (MetaCompositor *compositor);
 
-MetaBackend * meta_compositor_get_backend (MetaCompositor *compositor);
-
 MetaWindowActor * meta_compositor_get_top_window_actor (MetaCompositor *compositor);
-
-ClutterStage * meta_compositor_get_stage (MetaCompositor *compositor);
-
 gboolean meta_compositor_is_switching_workspace (MetaCompositor *compositor);
 
 gboolean meta_compositor_drag_window (MetaCompositor       *compositor,

src/compositor/compositor.c

@@ -208,27 +208,6 @@ get_compositor_for_display (MetaDisplay *display)
   return display->compositor;
 }
 
-/**
- * meta_get_stage_for_display:
- * @display: a #MetaDisplay
- *
- * Returns: (transfer none): The #ClutterStage for the display
- */
-ClutterActor *
-meta_get_stage_for_display (MetaDisplay *display)
-{
-  MetaCompositor *compositor;
-  MetaCompositorPrivate *priv;
-
-  g_return_val_if_fail (display, NULL);
-
-  compositor = get_compositor_for_display (display);
-  g_return_val_if_fail (compositor, NULL);
-  priv = meta_compositor_get_instance_private (compositor);
-
-  return meta_backend_get_stage (priv->backend);
-}
-
 /**
  * meta_get_window_group_for_display:
  * @display: a #MetaDisplay
@@ -1329,12 +1308,14 @@ void
 meta_compositor_flash_display (MetaCompositor *compositor,
                                MetaDisplay    *display)
 {
+  MetaBackend *backend;
   ClutterActor *stage;
   ClutterActor *flash;
   ClutterTransition *transition;
   gfloat width, height;
 
-  stage = meta_get_stage_for_display (display);
+  backend = meta_compositor_get_backend (compositor);
+  stage = meta_backend_get_stage (backend);
   clutter_actor_get_size (stage, &width, &height);
 
   flash = clutter_actor_new ();
@@ -1517,6 +1498,12 @@ meta_compositor_get_display (MetaCompositor *compositor)
   return priv->display;
 }
 
+/**
+ * meta_compositor_get_stage:
+ * @compositor: a #MetaCompositor
+ *
+ * Returns: (transfer none): The stage corresponding to @compositor
+ */
 ClutterStage *
 meta_compositor_get_stage (MetaCompositor *compositor)
 {
@@ -1526,6 +1513,12 @@ meta_compositor_get_stage (MetaCompositor *compositor)
   return CLUTTER_STAGE (meta_backend_get_stage (priv->backend));
 }
 
+/**
+ * meta_compositor_get_backend:
+ * @compositor: a #MetaCompositor
+ *
+ * Returns: (transfer none): The backend corresponding to @compositor
+ */
 MetaBackend *
 meta_compositor_get_backend (MetaCompositor *compositor)
 {

src/compositor/plugins/default.c

@@ -453,7 +453,7 @@ start (MetaPlugin *plugin)
   if (meta_is_wayland_compositor ())
     init_keymap (self, backend);
 
-  clutter_actor_show (meta_get_stage_for_display (display));
+  clutter_actor_show (meta_backend_get_stage (backend));
 }
 
 static void
@@ -462,6 +462,7 @@ switch_workspace (MetaPlugin *plugin,
                   MetaMotionDirection direction)
 {
   MetaDisplay *display;
+  MetaCompositor *compositor;
   MetaDefaultPluginPrivate *priv = META_DEFAULT_PLUGIN (plugin)->priv;
   GList        *l;
   ClutterActor *stage;
@@ -475,7 +476,8 @@ switch_workspace (MetaPlugin *plugin,
     }
 
   display = meta_plugin_get_display (plugin);
-  stage = meta_get_stage_for_display (display);
+  compositor = meta_display_get_compositor (display);
+  stage = CLUTTER_ACTOR (meta_compositor_get_stage (compositor));
 
   meta_display_get_size (display,
                          &screen_width,

src/meta/compositor-mutter.h

@@ -28,8 +28,6 @@
 #include "meta/types.h"
 
 /* Public compositor API */
-META_EXPORT
-ClutterActor *meta_get_stage_for_display            (MetaDisplay *display);
 
 META_EXPORT
 GList        *meta_get_window_actors                (MetaDisplay *display);

src/meta/compositor.h

@@ -71,3 +71,9 @@ MetaLaters * meta_compositor_get_laters (MetaCompositor *compositor);
 
 META_EXPORT
 ClutterActor * meta_compositor_get_feedback_group (MetaCompositor *compositor);
+
+META_EXPORT
+MetaBackend * meta_compositor_get_backend (MetaCompositor *compositor);
+
+META_EXPORT
+ClutterStage * meta_compositor_get_stage (MetaCompositor *compositor);

src/tests/meta-test-shell.c

@@ -368,7 +368,7 @@ meta_test_shell_start (MetaPlugin *plugin)
                     test_shell);
 
   if (test_shell->show_stage)
-    clutter_actor_show (meta_get_stage_for_display (display));
+    clutter_actor_show (meta_backend_get_stage (backend));
 }
 
 static void
@@ -378,6 +378,7 @@ meta_test_shell_switch_workspace (MetaPlugin          *plugin,
                                   MetaMotionDirection  direction)
 {
   MetaTestShell *test_shell = META_TEST_SHELL (plugin);
+  MetaCompositor *compositor;
   MetaDisplay *display;
   ClutterActor *stage;
   ClutterActor *workspace1, *workspace2;
@@ -391,7 +392,8 @@ meta_test_shell_switch_workspace (MetaPlugin          *plugin,
     }
 
   display = meta_plugin_get_display (plugin);
-  stage = meta_get_stage_for_display (display);
+  compositor = meta_display_get_compositor (display);
+  stage = CLUTTER_ACTOR (meta_compositor_get_stage (compositor));
 
   meta_display_get_size (display,
                          &screen_width,

src/x11/meta-x11-display.c

@@ -1276,7 +1276,7 @@ static gboolean
 stage_is_focused (MetaX11Display *x11_display)
 {
   MetaDisplay *display = x11_display->display;
-  ClutterStage *stage = CLUTTER_STAGE (meta_get_stage_for_display (display));
+  ClutterStage *stage = CLUTTER_STAGE (meta_compositor_get_stage (display->compositor));
   Window xwindow = meta_x11_get_stage_window (stage);
 
   return x11_display->focus_xwindow == xwindow;
@@ -1286,7 +1286,7 @@ static gboolean
 stage_has_focus_actor (MetaX11Display *x11_display)
 {
   MetaDisplay *display = x11_display->display;
-  ClutterStage *stage = CLUTTER_STAGE (meta_get_stage_for_display (display));
+  ClutterStage *stage = CLUTTER_STAGE (meta_compositor_get_stage (display->compositor));
   ClutterActor *key_focus;
 
   key_focus = clutter_stage_get_key_focus (stage);
@@ -1542,7 +1542,7 @@ meta_x11_display_new (MetaDisplay  *display,
   if (!meta_is_wayland_compositor ())
     {
       ClutterStage *stage =
-        CLUTTER_STAGE (meta_get_stage_for_display (display));
+        CLUTTER_STAGE (meta_backend_get_stage (backend));
 
       g_signal_connect_object (stage,
                                "notify::key-focus",
@@ -2327,7 +2327,7 @@ meta_x11_display_set_input_focus (MetaX11Display *x11_display,
   MetaFrame *frame;
 #ifdef HAVE_X11
   MetaDisplay *display = x11_display->display;
-  ClutterStage *stage = CLUTTER_STAGE (meta_get_stage_for_display (display));
+  ClutterStage *stage = CLUTTER_STAGE (meta_compositor_get_stage (display->compositor));
 #endif
 
   if (window && META_IS_WINDOW_X11 (window))