compositor: Setup and use ownership chains

As with the backend commit, this means all objects can reach the
MetaContext by walking up the chain, thus can e.g. get the backend from
the context, instead of the global singleton.

This also is a squashed commit containing:

compositor: Get backend via the context

The MetaCompositor instance is owned by MetaDisplay, which is owned by
MetaContext. Get the backend via that chain of ownership.

dnd: Don't get backend from singleton

window-actor: Don't get backend from singleton

dnd: Don't get Wayland compositor via singleton

background: Don't get the monitor manager from the singleton

plugins: Don't get backend from singleton

This applies to MetaPlugin, it's manager class, and the default plugin.

feedback-actor: Pass a compositor pointer when constructing

This allows getting to the display.

later: Keep a pointer to the manager object

This allows using the non-singleton API in idle callbacks.

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/2718>

1 files changed, 8 insertions, 2 deletions

diff --git a/src/compositor/meta-window-actor.c b/src/compositor/meta-window-actor.c
index 8299a7b7d..ba90c4c28 100644
--- a/src/compositor/meta-window-actor.c
+++ b/src/compositor/meta-window-actor.c
@@ -1222,13 +1222,16 @@ meta_window_actor_transform_cursor_position (MetaScreenCastWindow *screen_cast_w
       meta_cursor_sprite_get_cogl_texture (cursor_sprite) &&
       out_cursor_scale)
     {
+      MetaDisplay *display = meta_compositor_get_display (priv->compositor);
+      MetaContext *context = meta_display_get_context (display);
+      MetaBackend *backend = meta_context_get_backend (context);
       MetaLogicalMonitor *logical_monitor;
       float view_scale;
       float cursor_texture_scale;
 
       logical_monitor = meta_window_get_main_logical_monitor (window);
 
-      if (meta_is_stage_views_scaled ())
+      if (meta_backend_is_stage_views_scaled (backend))
         view_scale = meta_logical_monitor_get_scale (logical_monitor);
       else
         view_scale = 1.0;
@@ -1436,8 +1439,11 @@ create_framebuffer_from_window_actor (MetaWindowActor  *self,
                                       MetaRectangle    *clip,
                                       GError          **error)
 {
+  MetaWindowActorPrivate *priv = meta_window_actor_get_instance_private (self);
   ClutterActor *actor = CLUTTER_ACTOR (self);
-  MetaBackend *backend = meta_get_backend ();
+  MetaDisplay *display = meta_compositor_get_display (priv->compositor);
+  MetaContext *context = meta_display_get_context (display);
+  MetaBackend *backend = meta_context_get_backend (context);
   ClutterBackend *clutter_backend = meta_backend_get_clutter_backend (backend);
   CoglContext *cogl_context =
     clutter_backend_get_cogl_context (clutter_backend);