[gnome-shell/wip/exalm/gestures: 7/8] workspaceAnimation: Use window clones

[Alexander Mikhaylenko <alexm src gnome org>]

commit 1c20b5c8275c2050c5173e8f5c10b9e4c8c0c353
Author: Alexander Mikhaylenko <alexm gnome org>
Date:   Thu Jul 4 23:15:15 2019 +0500

    workspaceAnimation: Use window clones
    
    Instead of reparenting windows, clone them. This will allow to properly
    support multi-monitor setups in subsequent commits.
    
    Block window mapping animation while the animation is running to prevent
    new windows appearing during the animation from being visible at the same
    time as their clones.
    
    https://gitlab.gnome.org/GNOME/gnome-shell/merge_requests/605

 js/ui/workspaceAnimation.js | 19 +++++++++++--------
 1 file changed, 11 insertions(+), 8 deletions(-)
---
diff --git a/js/ui/workspaceAnimation.js b/js/ui/workspaceAnimation.js
index d9732b47b7..cc3f01d1bf 100644
--- a/js/ui/workspaceAnimation.js
+++ b/js/ui/workspaceAnimation.js
@@ -47,13 +47,17 @@ class WorkspaceGroup extends Clutter.Actor {
         windows = windows.filter(w => this._shouldShowWindow(w.meta_window));
 
         for (let window of windows) {
-            let record = { window,
-                           parent: window.get_parent() };
+            let clone = new Clutter.Clone({ source: window,
+                                            x: window.x,
+                                            y: window.y });
 
-            record.parent.remove_child(window)
-            this.add_child(window);
+            this.add_actor(clone);
+            window.hide();
+
+            let record = { window, clone };
 
             record.windowDestroyId = window.connect('destroy', () => {
+                clone.destroy();
                 this._windows.splice(this._windows.indexOf(record), 1);
             });
 
@@ -66,12 +70,11 @@ class WorkspaceGroup extends Clutter.Actor {
             let w = this._windows[i];
 
             w.window.disconnect(w.windowDestroyId);
-            this.remove_child(w.window);
-            w.parent.add_child(w.window)
+            w.clone.destroy();
 
-            if (w.window.get_meta_window().get_workspace() !=
+            if (w.window.get_meta_window().get_workspace() ==
                 global.workspace_manager.get_active_workspace())
-                w.window.hide();
+                w.window.show();
         }
 
         this._windows = [];