Improve dock hide animation

src/ShellClients/PanelWindow.vala

@@ -31,9 +31,6 @@ public class Gala.PanelWindow : ShellWindow, RootTarget {
     private GestureController gesture_controller;
     private HideTracker hide_tracker;
 
-    private int width = -1;
-    private int height = -1;
-
     public PanelWindow (WindowManager wm, Meta.Window window, Pantheon.Desktop.Anchor anchor) {
         Object (wm: wm, anchor: anchor, window: window, position: Position.from_anchor (anchor));
     }
@@ -53,6 +50,8 @@ public class Gala.PanelWindow : ShellWindow, RootTarget {
 
         window.size_changed.connect (update_strut);
         window.position_changed.connect (update_strut);
+        notify["width"].connect (update_strut);
+        notify["height"].connect (update_strut);
 
         gesture_controller = new GestureController (DOCK, wm);
         add_gesture_controller (gesture_controller);
@@ -62,32 +61,6 @@ public class Gala.PanelWindow : ShellWindow, RootTarget {
         hide_tracker.show.connect (show);
     }
 
-    public Mtk.Rectangle get_custom_window_rect () {
-        var window_rect = window.get_frame_rect ();
-
-        if (width > 0) {
-            window_rect.width = width;
-        }
-
-        if (height > 0) {
-            window_rect.height = height;
-
-            if (anchor == BOTTOM) {
-                var geom = wm.get_display ().get_monitor_geometry (window.get_monitor ());
-                window_rect.y = geom.y + geom.height - height;
-            }
-        }
-
-        return window_rect;
-    }
-
-    public void set_size (int width, int height) {
-        this.width = width;
-        this.height = height;
-
-        update_strut ();
-    }
-
     private void hide () {
         gesture_controller.goto (1);
     }

src/ShellClients/PositionedWindow.vala

@@ -29,6 +29,9 @@ public class Gala.PositionedWindow : Object {
     public Position position { get; construct set; }
     public Variant? position_data { get; construct set; }
 
+    private int width = -1;
+    private int height = -1;
+
     private ulong position_changed_id;
 
     public PositionedWindow (Meta.Window window, Position position, Variant? position_data = null) {
@@ -50,6 +53,30 @@ public class Gala.PositionedWindow : Object {
         notify["position-data"].connect (position_window);
     }
 
+    public Mtk.Rectangle get_custom_window_rect () {
+        var window_rect = window.get_frame_rect ();
+
+        if (width > 0) {
+            window_rect.width = width;
+        }
+
+        if (height > 0) {
+            window_rect.height = height;
+
+            if (position == BOTTOM) {
+                var geom = window.display.get_monitor_geometry (window.get_monitor ());
+                window_rect.y = geom.y + geom.height - height;
+            }
+        }
+
+        return window_rect;
+    }
+
+    public void set_size (int width, int height) {
+        this.width = width;
+        this.height = height;
+    }
+
     private void position_window () {
         int x = 0, y = 0;
         var window_rect = window.get_frame_rect ();

src/ShellClients/ShellWindow.vala

@@ -29,7 +29,7 @@ public class Gala.ShellWindow : PositionedWindow, GestureTarget {
         window_actor.notify["translation-y"].connect (update_clip);
         notify["position"].connect (update_clip);
 
-        window_actor.notify["height"].connect (update_target);
+        window.size_changed.connect (update_target);
         notify["position"].connect (update_target);
         update_target ();
     }
@@ -136,11 +136,13 @@ public class Gala.ShellWindow : PositionedWindow, GestureTarget {
     }
 
     private Value calculate_value (bool hidden) {
+        var custom_rect = get_custom_window_rect ();
+
         switch (position) {
             case TOP:
-                return hidden ? -window_actor.height : 0f;
+                return hidden ? -custom_rect.height : 0f;
             case BOTTOM:
-                return hidden ? window_actor.height : 0f;
+                return hidden ? custom_rect.height : 0f;
             default:
                 return hidden ? 0u : 255u;
         }