ActiveShape: use more opaque accent color (#2604)

This got overlooked in #2590

While we're here let's use bind_property instead of syncing accent color on demand

Author: lenemter

lib/Drawing/StyleManager.vala

@@ -33,7 +33,7 @@ public class Gala.Drawing.StyleManager : Object {
     private const uint8 ACCENT_COLOR_ALPHA = 64;
 
     private static GLib.Once<StyleManager> instance;
-    public static StyleManager get_instance () {
+    public static unowned StyleManager get_instance () {
         return instance.once (() => new StyleManager ());
     }
 

src/Widgets/MultitaskingView/WindowClone.vala

@@ -42,8 +42,6 @@ public class Gala.WindowClone : ActorTarget, RootTarget {
      */
     public bool active {
         set {
-            active_shape.update_color ();
-
             active_shape.save_easing_state ();
             active_shape.set_easing_duration (Utils.get_animation_duration (FADE_ANIMATION_DURATION));
             active_shape.opacity = value ? 255 : 0;
@@ -127,8 +125,9 @@ public class Gala.WindowClone : ActorTarget, RootTarget {
             add_action (drag_action);
         }
 
-        active_shape = new ActiveShape (monitor_scale);
-        active_shape.opacity = 0;
+        active_shape = new ActiveShape (monitor_scale) {
+            opacity = 0
+        };
         bind_property ("monitor-scale", active_shape, "monitor-scale");
 
         clone_container = new Clutter.Actor () {
@@ -675,7 +674,7 @@ public class Gala.WindowClone : ActorTarget, RootTarget {
      */
     private class ActiveShape : Clutter.Actor {
         private const int BORDER_RADIUS = 16;
-        private const double COLOR_OPACITY = 0.8;
+        private const uint8 COLOR_OPACITY = 204;
 
         public float monitor_scale { get; construct set; }
 
@@ -687,10 +686,19 @@ public class Gala.WindowClone : ActorTarget, RootTarget {
             var rounded_corners_effect = new RoundedCornersEffect (BORDER_RADIUS, monitor_scale);
             bind_property ("monitor-scale", rounded_corners_effect, "monitor-scale");
             add_effect (rounded_corners_effect);
-        }
 
-        public void update_color () {
-            background_color = Drawing.StyleManager.get_instance ().theme_accent_color;
+            unowned var style_manager = Drawing.StyleManager.get_instance ();
+            style_manager.bind_property ("theme-accent-color", this, "background-color", SYNC_CREATE, (binding, from_value, ref to_value) => {
+#if !HAS_MUTTER47
+                var new_color = (Clutter.Color) from_value;
+#else
+                var new_color = (Cogl.Color) from_value;
+#endif
+                new_color.alpha = COLOR_OPACITY;
+
+                to_value.set_boxed (&new_color);
+                return true;
+            });
         }
     }
 }