Add animation effects for smooth user experience

Implemented comprehensive animation effects throughout the extension:

1. Zone Overlay Animations:
   - Fade-in animation (200ms) when showing zones
   - Fade-out animation (150ms) when hiding zones
   - Uses Clutter.AnimationMode.EASE_OUT_QUAD for smooth easing

2. Window Snapping Animations:
   - Smooth animated window movement (250ms) when snapping to zones
   - Animates window actor position and size
   - Falls back to instant move if actor not available
   - Final position set precisely after animation completes

3. Visual Snap Feedback:
   - Green flash effect when window snaps to zone
   - Flash shows the exact zone boundaries
   - Fades out over 400ms
   - Works for both Shift+drag and keyboard snapping

Implementation details:
- Used Clutter's ease() method for all animations
- Overlay fade animations prevent jarring appearance/disappearance
- Window animations use compositor actor for smooth transitions
- Flash feedback uses temporary widget with auto-cleanup
- All animations use EASE_OUT_QUAD for natural feel

User experience improvements:
- Zones appear and disappear smoothly instead of instantly
- Windows glide into position rather than jumping
- Clear visual confirmation when snap occurs
- Professional, polished feel throughout

Fixes TODO item #11.

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

TODO.md

@@ -111,11 +111,11 @@
 - [ ] 1/3 - 2/3 layouts
 - [ ] Picture-in-picture style layouts
 
-### 11. Animation Effects
+### 11. Animation Effects ✅ COMPLETED
 **Priority: Low**
-- [ ] Add smooth transitions when snapping windows
-- [ ] Animate zone overlay appearance/disappearance
-- [ ] Visual feedback when window snaps to zone
+- [x] Add smooth transitions when snapping windows
+- [x] Animate zone overlay appearance/disappearance
+- [x] Visual feedback when window snaps to zone
 
 ### 12. Settings Panel ✅ COMPLETED
 **Priority: Medium**

extension.js

@@ -1071,6 +1071,14 @@ ZoneManager.prototype = {
         
         Main.layoutManager.addChrome(this.overlay);
         this.isShowing = true;
+
+        // Fade in animation
+        this.overlay.opacity = 0;
+        this.overlay.ease({
+            opacity: 255,
+            duration: 200,
+            mode: Clutter.AnimationMode.EASE_OUT_QUAD
+        });
     },
     
     _createZoneActor: function(zone, monitor, index) {
@@ -1126,13 +1134,23 @@ ZoneManager.prototype = {
     _hideZonesOverlay: function() {
         if (!this.isShowing) return;
 
+        this.isShowing = false;
+
+        if (this.overlay) {
+            // Fade out animation
+            this.overlay.ease({
+                opacity: 0,
+                duration: 150,
+                mode: Clutter.AnimationMode.EASE_OUT_QUAD,
+                onComplete: () => {
                     if (this.overlay) {
                         Main.layoutManager.removeChrome(this.overlay);
                         this.overlay.destroy();
                         this.overlay = null;
                     }
-        
-        this.isShowing = false;
+                }
+            });
+        }
     },
     
     _snapWindowToZone: function(window) {
@@ -1159,6 +1177,7 @@ ZoneManager.prototype = {
 
         if (targetZone) {
             this._moveWindowToZone(window, targetZone, monitor);
+            this._showSnapFeedback(targetZone, monitor);
 
             // Show notification if enabled
             if (this.settings.getValue('notification-on-snap')) {
@@ -1181,7 +1200,9 @@ ZoneManager.prototype = {
         if (zoneIndex >= layout.zones.length) return;
 
         let monitor = Main.layoutManager.primaryMonitor;
-        this._moveWindowToZone(window, layout.zones[zoneIndex], monitor);
+        let targetZone = layout.zones[zoneIndex];
+        this._moveWindowToZone(window, targetZone, monitor);
+        this._showSnapFeedback(targetZone, monitor);
 
         // Show notification if enabled
         if (this.settings.getValue('notification-on-snap')) {
@@ -1189,6 +1210,42 @@ ZoneManager.prototype = {
         }
     },
 
+    _showSnapFeedback: function(zone, monitor) {
+        // Create a flash effect on the zone to show snap feedback
+        let x = monitor.x + Math.round(monitor.width * zone.x);
+        let y = monitor.y + Math.round(monitor.height * zone.y);
+        let width = Math.round(monitor.width * zone.width);
+        let height = Math.round(monitor.height * zone.height);
+
+        let flashActor = new St.Widget({
+            style_class: 'gridsnap-flash',
+            x: x,
+            y: y,
+            width: width,
+            height: height
+        });
+
+        flashActor.set_style(
+            'border: 4px solid rgba(100, 255, 100, 1.0);' +
+            'background-color: rgba(100, 255, 100, 0.3);' +
+            'border-radius: 4px;'
+        );
+
+        Main.layoutManager.addChrome(flashActor);
+
+        // Animate flash effect
+        flashActor.opacity = 255;
+        flashActor.ease({
+            opacity: 0,
+            duration: 400,
+            mode: Clutter.AnimationMode.EASE_OUT_QUAD,
+            onComplete: () => {
+                Main.layoutManager.removeChrome(flashActor);
+                flashActor.destroy();
+            }
+        });
+    },
+    
     _moveWindowToZone: function(window, zone, monitor) {
         if (!window || !zone || !monitor) return;
 
@@ -1206,8 +1263,26 @@ ZoneManager.prototype = {
         // Use Mainloop.idle_add to defer the operation
         // This ensures the unmaximize completes before move/resize
         Mainloop.idle_add(Lang.bind(this, function() {
-            // Move and resize window (false = programmatic operation, not user-initiated)
+            // Get window actor for animation
+            let actor = window.get_compositor_private();
+            if (actor) {
+                // Animate window movement
+                actor.ease({
+                    x: x,
+                    y: y,
+                    width: width,
+                    height: height,
+                    duration: 250,
+                    mode: Clutter.AnimationMode.EASE_OUT_QUAD,
+                    onComplete: () => {
+                        // Set final position precisely after animation
                         window.move_resize_frame(false, x, y, width, height);
+                    }
+                });
+            } else {
+                // Fallback to instant move if no actor
+                window.move_resize_frame(false, x, y, width, height);
+            }
             return false; // Don't repeat
         }));
     },