Fix window maximize and unmaximize animations

data/gala.appdata.xml.in

@@ -30,6 +30,8 @@
         <issue url="https://github.com/elementary/gala/issues/1482">Duplicate "Plus" workspaces</issue>
         <issue url="https://github.com/elementary/gala/issues/1203">Artifact around non native apps in the overview mode</issue>
         <issue url="https://github.com/elementary/gala/issues/1505">"Not responding" dialog and not responding app close after inactivity</issue>
+        <issue url="https://github.com/elementary/gala/issues/1185">Unmaximize effect not working with mutter >= 3.38</issue>
+        <issue url="https://github.com/elementary/gala/issues/1536">Several (un-)maximize animations are not played</issue>
       </issues>
     </release>
 

lib/Utils.vala

@@ -271,44 +271,28 @@ namespace Gala {
         /**
          * Creates an actor showing the current contents of the given WindowActor.
          *
-         * @param actor      The actor from which to create a shnapshot
+         * @param actor      The actor from which to create a snapshot
          * @param inner_rect The inner (actually visible) rectangle of the window
          * @param outer_rect The outer (input region) rectangle of the window
          *
          * @return           A copy of the actor at that time or %NULL
          */
         public static Clutter.Actor? get_window_actor_snapshot (
             Meta.WindowActor actor,
-            Meta.Rectangle inner_rect,
-            Meta.Rectangle outer_rect
+            Meta.Rectangle inner_rect
         ) {
-            var texture = actor.get_texture () as Meta.ShapedTexture;
+            Clutter.Content content;
 
-            if (texture == null)
-                return null;
-
-            var surface = texture.get_image ({
-                inner_rect.x - outer_rect.x,
-                inner_rect.y - outer_rect.y,
-                inner_rect.width,
-                inner_rect.height
-            });
-
-            if (surface == null)
+            try {
+                content = actor.paint_to_content (inner_rect);
+            } catch (Error e) {
+                warning ("Could not create window snapshot: %s", e.message);
                 return null;
-
-            var canvas = new Clutter.Canvas ();
-            var handler = canvas.draw.connect ((cr) => {
-                cr.set_source_surface (surface, 0, 0);
-                cr.paint ();
-                return false;
-            });
-            canvas.set_size (inner_rect.width, inner_rect.height);
-            SignalHandler.disconnect (canvas, handler);
+            }
 
             var container = new Clutter.Actor ();
             container.set_size (inner_rect.width, inner_rect.height);
-            container.content = canvas;
+            container.content = content;
 
             return container;
         }

src/WindowManager.vala

@@ -104,6 +104,7 @@ namespace Gala {
         private GLib.HashTable<Meta.Window, int> ws_assoc = new GLib.HashTable<Meta.Window, int> (direct_hash, direct_equal);
         private Meta.SizeChange? which_change = null;
         private Meta.Rectangle old_rect_size_change;
+        private Clutter.Actor latest_window_snapshot;
 
         private GLib.Settings animations_settings;
         private GLib.Settings behavior_settings;
@@ -1062,6 +1063,8 @@ namespace Gala {
         public override void size_change (Meta.WindowActor actor, Meta.SizeChange which_change_local, Meta.Rectangle old_frame_rect, Meta.Rectangle old_buffer_rect) {
             which_change = which_change_local;
             old_rect_size_change = old_frame_rect;
+
+            latest_window_snapshot = Utils.get_window_actor_snapshot (actor, old_frame_rect);
         }
 
         // size_changed gets called after frame_rect has updated
@@ -1193,7 +1196,7 @@ namespace Gala {
                 var old_inner_rect = window_geometry != null ? window_geometry.inner : fallback;
                 var old_outer_rect = window_geometry != null ? window_geometry.outer : fallback;
 
-                var old_actor = Utils.get_window_actor_snapshot (actor, old_inner_rect, old_outer_rect);
+                var old_actor = Utils.get_window_actor_snapshot (actor, old_inner_rect);
                 if (old_actor == null) {
                     return;
                 }
@@ -1586,41 +1589,40 @@ namespace Gala {
                     offset_height = 0;
                 }
 
-                Meta.Rectangle old_rect = { (int) actor.x, (int) actor.y, (int) actor.width, (int) actor.height };
-                var old_actor = Utils.get_window_actor_snapshot (actor, old_rect, old_rect);
-
-                if (old_actor == null) {
+                if (latest_window_snapshot == null) {
                     return;
                 }
 
                 unmaximizing.add (actor);
 
-                old_actor.set_position (old_rect.x, old_rect.y);
+                // FIXME: Gtk windows don't want to go out of bounds of screen when unmaximizing, so place them manually
+                // This is OS 7 (Mutter 42) specific, this was not needed in OS 6
+                window.move_frame (true, ex, ey);
 
-                ui_group.add_child (old_actor);
+                latest_window_snapshot.set_position (old_rect_size_change.x, old_rect_size_change.y);
 
-                var scale_x = (float) ew / old_rect.width;
-                var scale_y = (float) eh / old_rect.height;
+                ui_group.add_child (latest_window_snapshot);
 
-                old_actor.save_easing_state ();
-                old_actor.set_easing_mode (Clutter.AnimationMode.EASE_IN_OUT_QUAD);
-                old_actor.set_easing_duration (duration);
-                old_actor.set_position (ex, ey);
-                old_actor.set_scale (scale_x, scale_y);
-                old_actor.opacity = 0U;
-                old_actor.restore_easing_state ();
+                var scale_x = (float) ew / old_rect_size_change.width;
+                var scale_y = (float) eh / old_rect_size_change.height;
+
+                latest_window_snapshot.save_easing_state ();
+                latest_window_snapshot.set_easing_mode (Clutter.AnimationMode.EASE_IN_OUT_QUAD);
+                latest_window_snapshot.set_easing_duration (duration);
+                latest_window_snapshot.set_position (ex, ey);
+                latest_window_snapshot.set_scale (scale_x, scale_y);
+                latest_window_snapshot.opacity = 0U;
+                latest_window_snapshot.restore_easing_state ();
 
                 ulong unmaximize_old_handler_id = 0UL;
-                unmaximize_old_handler_id = old_actor.transitions_completed.connect (() => {
-                    old_actor.disconnect (unmaximize_old_handler_id);
-                    old_actor.destroy ();
+                unmaximize_old_handler_id = latest_window_snapshot.transitions_completed.connect (() => {
+                    latest_window_snapshot.disconnect (unmaximize_old_handler_id);
+                    latest_window_snapshot.destroy ();
                 });
 
-                var maximized_x = actor.x;
-                var maximized_y = actor.y;
                 actor.set_pivot_point (0.0f, 0.0f);
                 actor.set_position (ex, ey);
-                actor.set_translation (-ex + offset_x * (1.0f / scale_x - 1.0f) + maximized_x, -ey + offset_y * (1.0f / scale_y - 1.0f) + maximized_y, 0.0f);
+                actor.set_translation (-ex + offset_x * (1.0f / scale_x - 1.0f) + old_rect_size_change.x, -ey + offset_y * (1.0f / scale_y - 1.0f) + old_rect_size_change.y, 0.0f);
                 actor.set_scale (1.0f / scale_x, 1.0f / scale_y);
 
                 actor.save_easing_state ();