[gnome-shell/wip/exalm/gestures2: 32/33] workspaceAnimation: Group sticky windows and moving window

[Alexander Mikhaylenko <alexm src gnome org>]

commit a740b906e54796ceb52515979bfc1add729df469
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 2617f100c5..f2be4fd882 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 (let window of windows) {
+            let clone = new Clutter.Clone({
+                source: window,
+                x: window.x,
+                y: window.y,
+            });
+
+            this.add_child(clone);
+            window.hide();
+
+            let record = { window, clone };
+
+            record.windowDestroyId = window.connect('destroy', () => {
+                clone.destroy();
+                this._windows.splice(this._windows.indexOf(record), 1);
+            });
+
+            this._windows.push(record);
+        }
+    }
+
+    _removeWindows() {
+        for (const record of this._windows) {
+            record.window.disconnect(record.windowDestroyId);
+            record.clone.destroy();
+
+            record.window.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 {
         let 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;
@@ -188,38 +254,14 @@ var WorkspaceAnimationController = class {
         else
             switchData.container.x = -switchData.workspaces[activeWorkspaceIndex].x;
 
-        wgroup.set_child_above_sibling(switchData.movingWindowBin, null);
-
-        if (this.movingWindow) {
-            const actor = this.movingWindow.get_compositor_private();
-
-            switchData.movingWindow = {
-                window: actor,
-                parent: actor.get_parent(),
-            };
-
-            switchData.movingWindow.parent.remove_child(actor);
-            switchData.movingWindowBin.add_child(actor);
-            switchData.movingWindow.windowDestroyId = actor.connect('destroy', () => {
-                switchData.movingWindow = null;
-            });
-        }
+        wgroup.set_child_above_sibling(switchData.stickyGroup, null);
     }
 
     _finishWorkspaceSwitch(switchData) {
         this._switchData = null;
 
-        if (switchData.movingWindow) {
-            let record = switchData.movingWindow;
-            record.window.disconnect(record.windowDestroyId);
-            record.window.get_parent().remove_child(record.window);
-            record.parent.add_child(record.window);
-
-            switchData.movingWindow = null;
-        }
-
         switchData.container.destroy();
-        switchData.movingWindowBin.destroy();
+        switchData.stickyGroup.destroy();
 
         this.movingWindow = null;
     }