clutter: Pass target actor of events to event filter functions

We'll need the additional context of which actor the event will be
emitted to in mutters event filter (see next commit), so pass that
target actor to the event filters that are installed.

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/2321>

clutter/clutter/clutter-event-private.h

@@ -14,7 +14,8 @@ CLUTTER_EXPORT
 void            _clutter_process_event                  (ClutterEvent       *event);
 
 CLUTTER_EXPORT
-gboolean        _clutter_event_process_filters          (ClutterEvent       *event);
+gboolean        _clutter_event_process_filters          (ClutterEvent *event,
+                                                         ClutterActor *event_actor);
 
 /* clears the event queue inside the main context */
 void            _clutter_clear_events_queue             (void);

clutter/clutter/clutter-event.c

@@ -1772,7 +1772,8 @@ clutter_event_is_pointer_emulated (const ClutterEvent *event)
 }
 
 gboolean
-_clutter_event_process_filters (ClutterEvent *event)
+_clutter_event_process_filters (ClutterEvent *event,
+                                ClutterActor *event_actor)
 {
   ClutterMainContext *context = _clutter_context_get_default ();
   GList *l, *next;
@@ -1789,7 +1790,7 @@ _clutter_event_process_filters (ClutterEvent *event)
       if (event_filter->stage && event_filter->stage != event->any.stage)
         continue;
 
-      if (event_filter->func (event, event_filter->user_data) == CLUTTER_EVENT_STOP)
+      if (event_filter->func (event, event_actor, event_filter->user_data) == CLUTTER_EVENT_STOP)
         return CLUTTER_EVENT_STOP;
     }
 

clutter/clutter/clutter-event.h

@@ -615,6 +615,7 @@ union _ClutterEvent
 /**
  * ClutterEventFilterFunc:
  * @event: the event that is going to be emitted
+ * @event_actor: the current device actor of the events device
  * @user_data: the data pointer passed to clutter_event_add_filter()
  *
  * A function pointer type used by event filters that are added with
@@ -628,6 +629,7 @@ union _ClutterEvent
  * Since: 1.18
  */
 typedef gboolean (* ClutterEventFilterFunc) (const ClutterEvent *event,
+                                             ClutterActor       *event_actor,
                                              gpointer            user_data);
 
 CLUTTER_EXPORT

clutter/clutter/clutter-main.c

@@ -741,6 +741,8 @@ update_device_for_event (ClutterStage *stage,
 void
 clutter_do_event (ClutterEvent *event)
 {
+  ClutterActor *event_actor = NULL;
+
   /* we need the stage for the event */
   if (event->any.stage == NULL)
     {
@@ -765,7 +767,15 @@ clutter_do_event (ClutterEvent *event)
       break;
     }
 
-  if (_clutter_event_process_filters (event))
+  if (event->any.type != CLUTTER_DEVICE_ADDED &&
+      event->any.type != CLUTTER_DEVICE_REMOVED &&
+      event->any.type != CLUTTER_NOTHING &&
+      event->any.type != CLUTTER_EVENT_LAST)
+    {
+      event_actor = clutter_stage_get_event_actor (event->any.stage, event);
+    }
+
+  if (_clutter_event_process_filters (event, event_actor))
     return;
 
   /* Instead of processing events when received, we queue them up to

clutter/clutter/clutter-stage.c

@@ -3478,7 +3478,7 @@ clutter_stage_update_device (ClutterStage         *stage,
                                          CLUTTER_EVENT_NONE,
                                          old_actor, new_actor,
                                          point, time_ms);
-          if (!_clutter_event_process_filters (event))
+          if (!_clutter_event_process_filters (event, old_actor))
             _clutter_actor_handle_event (old_actor, root, event);
 
           clutter_event_free (event);
@@ -3492,7 +3492,7 @@ clutter_stage_update_device (ClutterStage         *stage,
                                          CLUTTER_EVENT_NONE,
                                          new_actor, old_actor,
                                          point, time_ms);
-          if (!_clutter_event_process_filters (event))
+          if (!_clutter_event_process_filters (event, new_actor))
             _clutter_actor_handle_event (new_actor, root, event);
 
           clutter_event_free (event);
@@ -3676,7 +3676,7 @@ clutter_stage_notify_grab_on_pointer_entry (ClutterStage       *stage,
                                      grab_actor : old_grab_actor,
                                      entry->coords,
                                      CLUTTER_CURRENT_TIME);
-      if (!_clutter_event_process_filters (event))
+      if (!_clutter_event_process_filters (event, entry->current_actor))
         _clutter_actor_handle_event (deepmost, topmost, event);
       clutter_event_free (event);
     }

src/core/events.c

@@ -213,7 +213,8 @@ maybe_unfreeze_pointer_events (MetaBackend          *backend,
 
 static gboolean
 meta_display_handle_event (MetaDisplay        *display,
-                           const ClutterEvent *event)
+                           const ClutterEvent *event,
+                           ClutterActor       *event_actor)
 {
   MetaBackend *backend = meta_get_backend ();
   MetaWindow *window = NULL;
@@ -540,11 +541,12 @@ meta_display_handle_event (MetaDisplay        *display,
 
 static gboolean
 event_callback (const ClutterEvent *event,
+                ClutterActor       *event_actor,
                 gpointer            data)
 {
   MetaDisplay *display = data;
 
-  return meta_display_handle_event (display, event);
+  return meta_display_handle_event (display, event, event_actor);
 }
 
 void