[mutter] plugins/default: Fix broken switch_workspace()

[Marge Bot <marge-bot src gnome org>]

commit 888e69d3a4b986351dc0681358781fd7238d7d71
Author: Mark <markjr92892 gmail com>
Date:   Sat Dec 4 05:06:53 2021 -0600

    plugins/default: Fix broken switch_workspace()
    
    Swap which windows are switched with which in the workspace switching
    animation of the default plugin since this was backwards (resulting in
    failures), but animate only those which are on either the current
    workspace or the one to switch to. Have the animation span the entire
    screen as intended.
    
    Related: https://gitlab.gnome.org/GNOME/mutter/-/issues/2038
    Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/2076>

 src/compositor/plugins/default.c | 91 ++++++++++++++++++++++------------------
 1 file changed, 50 insertions(+), 41 deletions(-)
---
diff --git a/src/compositor/plugins/default.c b/src/compositor/plugins/default.c
index f762b3e6e2..3d09c49975 100644
--- a/src/compositor/plugins/default.c
+++ b/src/compositor/plugins/default.c
@@ -503,11 +503,16 @@ switch_workspace (MetaPlugin *plugin,
   MetaDisplay *display;
   MetaDefaultPluginPrivate *priv = META_DEFAULT_PLUGIN (plugin)->priv;
   GList        *l;
-  ClutterActor *workspace0  = clutter_actor_new ();
-  ClutterActor *workspace1  = clutter_actor_new ();
   ClutterActor *stage;
+  ClutterActor *workspace1, *workspace2;
   int           screen_width, screen_height;
 
+  if (from == to)
+    {
+      meta_plugin_switch_workspace_completed (plugin);
+      return;
+    }
+
   display = meta_plugin_get_display (plugin);
   stage = meta_get_stage_for_display (display);
 
@@ -515,66 +520,70 @@ switch_workspace (MetaPlugin *plugin,
                          &screen_width,
                          &screen_height);
 
+  workspace1 = clutter_actor_new ();
+  workspace2 = clutter_actor_new ();
+
   clutter_actor_set_pivot_point (workspace1, 1.0, 1.0);
-  clutter_actor_set_position (workspace1,
-                              screen_width,
-                              screen_height);
+  clutter_actor_set_size (workspace1,
+                          screen_width,
+                          screen_height);
+  clutter_actor_set_size (workspace2,
+                          screen_width,
+                          screen_height);
 
   clutter_actor_set_scale (workspace1, 0.0, 0.0);
 
   clutter_actor_add_child (stage, workspace1);
-  clutter_actor_add_child (stage, workspace0);
+  clutter_actor_add_child (stage, workspace2);
 
-  if (from == to)
-    {
-      meta_plugin_switch_workspace_completed (plugin);
-      return;
-    }
-
-  l = g_list_last (meta_get_window_actors (display));
-
-  while (l)
+  for (l = g_list_last (meta_get_window_actors (display)); l; l = l->prev)
     {
       MetaWindowActor *window_actor = l->data;
       ActorPrivate    *apriv       = get_actor_private (window_actor);
       ClutterActor    *actor       = CLUTTER_ACTOR (window_actor);
-      MetaWorkspace   *workspace;
-      gint             win_workspace;
+      MetaWindow      *window;
 
-      workspace = meta_window_get_workspace (meta_window_actor_get_meta_window (window_actor));
-      win_workspace = meta_workspace_index (workspace);
+      window = meta_window_actor_get_meta_window (window_actor);
 
-      if (win_workspace == to || win_workspace == from)
-        {
-          ClutterActor *parent = win_workspace == to ? workspace1 : workspace0;
-          apriv->orig_parent = clutter_actor_get_parent (actor);
-
-          g_object_ref (actor);
-          clutter_actor_remove_child (clutter_actor_get_parent (actor), actor);
-          clutter_actor_add_child (parent, actor);
-          clutter_actor_show (actor);
-          clutter_actor_set_child_below_sibling (parent, actor, NULL);
-          g_object_unref (actor);
-        }
-      else if (win_workspace < 0)
+      if (meta_window_is_on_all_workspaces (window))
         {
           /* Sticky window */
           apriv->orig_parent = NULL;
         }
       else
         {
-          /* Window on some other desktop */
-          clutter_actor_hide (actor);
-          apriv->orig_parent = NULL;
+          MetaWorkspace *workspace;
+          gint           win_workspace;
+
+          workspace = meta_window_get_workspace (window);
+          win_workspace = meta_workspace_index (workspace);
+
+          if (win_workspace == to || win_workspace == from)
+            {
+              ClutterActor *parent = win_workspace == to ? workspace1
+                                                         : workspace2;
+              apriv->orig_parent = clutter_actor_get_parent (actor);
+
+              g_object_ref (actor);
+              clutter_actor_remove_child (clutter_actor_get_parent (actor),
+                                          actor);
+              clutter_actor_add_child (parent, actor);
+              clutter_actor_set_child_below_sibling (parent, actor, NULL);
+              g_object_unref (actor);
+            }
+          else
+            {
+              /* Window on some other desktop */
+              clutter_actor_hide (actor);
+              apriv->orig_parent = NULL;
+            }
         }
-
-      l = l->prev;
     }
 
-  priv->desktop1 = workspace0;
-  priv->desktop2 = workspace1;
+  priv->desktop1 = workspace1;
+  priv->desktop2 = workspace2;
 
-  priv->tml_switch_workspace1 = actor_animate (workspace0, CLUTTER_EASE_IN_SINE,
+  priv->tml_switch_workspace1 = actor_animate (workspace1, CLUTTER_EASE_IN_SINE,
                                                ANIMATION_SWITCH,
                                                "scale-x", 1.0,
                                                "scale-y", 1.0,
@@ -584,7 +593,7 @@ switch_workspace (MetaPlugin *plugin,
                     G_CALLBACK (on_switch_workspace_effect_complete),
                     plugin);
 
-  priv->tml_switch_workspace2 = actor_animate (workspace1, CLUTTER_EASE_IN_SINE,
+  priv->tml_switch_workspace2 = actor_animate (workspace2, CLUTTER_EASE_IN_SINE,
                                                ANIMATION_SWITCH,
                                                "scale-x", 0.0,
                                                "scale-y", 0.0,