[gnome-shell/wip/exalm/gestures2: 6/7] workspaceAnimation: Group sticky windows and moving window

[Alexander Mikhaylenko <alexm src gnome org>]

commit f69d71f3dc991fc2663fb8c5d064a7fc8fa997f0
Author: Alexander Mikhaylenko <exalm7659 gmail com>
Date:   Sat Jun 20 23:44:24 2020 +0500

    workspaceAnimation: Group sticky windows and moving window
    
    Since the transitions consists of window clones now, all the clones appear
    above sticky windows. Clone sticky windows as well, and treat them same as
    moving window instead.
    
    https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/1326

 js/ui/workspaceAnimation.js | 100 +++++++++++++++++++++++++++++++-------------
 1 file changed, 71 insertions(+), 29 deletions(-)
---
diff --git a/js/ui/workspaceAnimation.js b/js/ui/workspaceAnimation.js
index d09311a7dd..a0270d118b 100644
--- a/js/ui/workspaceAnimation.js
+++ b/js/ui/workspaceAnimation.js
@@ -86,6 +86,73 @@ class WorkspaceGroup extends Clutter.Actor {
     }
 });
 
+const StickyGroup = GObject.registerClass(
+class StickyGroup extends Clutter.Actor {
+    _init(movingWindow) {
+        super._init();
+
+        this._movingWindow = movingWindow;
+        this._windows = [];
+
+        this._refreshWindows();
+
+        this.connect('destroy', this._onDestroy.bind(this));
+        this._restackedId = global.display.connect('restacked',
+            this._refreshWindows.bind(this));
+    }
+
+    _shouldShowWindow(window) {
+        if (!window.showing_on_its_workspace())
+            return false;
+
+        return window.is_on_all_workspaces() || window === this._movingWindow;
+    }
+
+    _refreshWindows() {
+        if (this._windows.length > 0)
+            this._removeWindows();
+
+        const windows = global.get_window_actors().filter(w =>
+            this._shouldShowWindow(w.meta_window));
+
+        for (const windowActor of windows) {
+            const clone = new Clutter.Clone({
+                source: windowActor,
+                x: windowActor.x,
+                y: windowActor.y,
+            });
+
+            this.add_child(clone);
+            windowActor.hide();
+
+            const record = { windowActor, clone };
+
+            record.windowDestroyId = windowActor.connect('destroy', () => {
+                clone.destroy();
+                this._windows.splice(this._windows.indexOf(record), 1);
+            });
+
+            this._windows.push(record);
+        }
+    }
+
+    _removeWindows() {
+        for (const record of this._windows) {
+            record.windowActor.disconnect(record.windowDestroyId);
+            record.clone.destroy();
+
+            record.windowActor.show();
+        }
+
+        this._windows = [];
+    }
+
+    _onDestroy() {
+        global.display.disconnect(this._restackedId);
+        this._removeWindows();
+    }
+});
+
 var WorkspaceAnimationController = class {
     constructor() {
         this._movingWindow = null;
@@ -123,15 +190,14 @@ var WorkspaceAnimationController = class {
         const switchData = {};
 
         this._switchData = switchData;
-        switchData.movingWindowBin = new Clutter.Actor();
-        switchData.movingWindow = null;
+        switchData.stickyGroup = new StickyGroup(this.movingWindow);
         switchData.workspaces = [];
         switchData.gestureActivated = false;
         switchData.inProgress = false;
 
         switchData.container = new Clutter.Actor();
 
-        wgroup.add_child(switchData.movingWindowBin);
+        wgroup.add_child(switchData.stickyGroup);
         wgroup.add_child(switchData.container);
 
         let x = 0;
@@ -181,38 +247,14 @@ var WorkspaceAnimationController = class {
         else
             switchData.container.x = -switchData.workspaces[activeWorkspaceIndex].x;
 
-        wgroup.set_child_above_sibling(switchData.movingWindowBin, null);
-
-        if (this.movingWindow) {
-            const windowActor = this.movingWindow.get_compositor_private();
-
-            switchData.movingWindow = {
-                windowActor,
-                parent: windowActor.get_parent(),
-            };
-
-            switchData.movingWindow.parent.remove_child(windowActor);
-            switchData.movingWindowBin.add_child(windowActor);
-            switchData.movingWindow.windowDestroyId = windowActor.connect('destroy', () => {
-                switchData.movingWindow = null;
-            });
-        }
+        wgroup.set_child_above_sibling(switchData.stickyGroup, null);
     }
 
     _finishWorkspaceSwitch(switchData) {
         this._switchData = null;
 
-        if (switchData.movingWindow) {
-            const record = switchData.movingWindow;
-            record.windowActor.disconnect(record.windowDestroyId);
-            switchData.movingWindowBin.remove_child(record.windowActor);
-            record.parent.add_child(record.windowActor);
-
-            switchData.movingWindow = null;
-        }
-
         switchData.container.destroy();
-        switchData.movingWindowBin.destroy();
+        switchData.stickyGroup.destroy();
 
         this.movingWindow = null;
     }