Add support for looping

Author: adamgraham

Runtime/LoopType.cs

@@ -0,0 +1,33 @@
+namespace Zigurous.Tweening
+{
+    /// <summary>
+    /// A type of loop style.
+    /// </summary>
+    public enum LoopType
+    {
+        /// <summary>
+        /// Restarts the tween from the beginning after it ends.
+        /// </summary>
+        Restart,
+
+        /// <summary>
+        /// Restarts the tween from the beginning after it ends. If the tween
+        /// has a delay it will be delayed again each loop.
+        /// </summary>
+        RestartWithDelay,
+
+        /// <summary>
+        /// Plays the tween forwards then backwards then forwards then
+        /// backwards, etc.
+        /// </summary>
+        PingPong,
+
+        /// <summary>
+        /// Plays the tween forwards then backwards then forwards then
+        /// backwards, etc.  If the tween has a delay it will be delayed again
+        /// each loop.
+        /// </summary>
+        PingPongWithDelay,
+    }
+
+}

Runtime/LoopType.cs.meta

@@ -41,6 +41,13 @@ public static T SetDelay<T>(this T tween, float delay) where T: Tween
             return tween;
         }
 
+        public static T SetLoops<T>(this T tween, int loops, LoopType loopType = LoopType.Restart) where T: Tween
+        {
+            tween.loops = loops;
+            tween.loopType = loopType;
+            return tween;
+        }
+
         public static T SetReversed<T>(this T tween, bool reversed = true) where T: Tween
         {
             tween.reversed = reversed;
@@ -83,6 +90,12 @@ public static T OnStop<T>(this T tween, TweenCallback callback) where T: Tween
             return tween;
         }
 
+        public static T OnLoop<T>(this T tween, TweenCallback callback) where T: Tween
+        {
+            tween.onLoop += callback;
+            return tween;
+        }
+
         public static T OnComplete<T>(this T tween, TweenCallback callback) where T: Tween
         {
             tween.onComplete += callback;

Runtime/PropertyChaining.cs

@@ -41,6 +41,11 @@ public Sequence() : base()
             this.type = TweenType.Sequence;
         }
 
+        public override void Animate()
+        {
+            // Do nothing. The individual tweens are animated on their own.
+        }
+
         /// <summary>
         /// Plays the tween sequence, whether starting for the first time or
         /// resuming from a stopped state.
@@ -79,28 +84,35 @@ private Tween Prepare(Tween tween)
 
         private void Next()
         {
-            this.currentIndex++;
-
-            if (CanComplete()) {
-                Complete();
+            if (this.reversed) {
+                this.currentIndex--;
             } else {
-                this.tweens[this.currentIndex].Play();
+                this.currentIndex++;
             }
-        }
 
-        protected override void Animate()
-        {
-            // Do nothing. The individual tweens are animated on their own.
+            Tween tween = this.activeTween;
+
+            if (tween != null) {
+                tween.Play();
+            }
         }
 
-        protected override bool CanComplete()
+        protected override bool IsFinished()
         {
-            return this.currentIndex >= this.tweens.Count;
+            if (this.reversed) {
+                return this.currentIndex < 0;
+            } else {
+                return this.currentIndex >= this.tweens.Count;
+            }
         }
 
         protected override void OnStart()
         {
-            this.currentIndex = 0;
+            if (this.reversed) {
+                this.currentIndex = this.tweens.Count - 1;
+            } else {
+                this.currentIndex = 0;
+            }
 
             Tween tween = this.activeTween;
 
@@ -127,6 +139,19 @@ protected override void OnResume()
             }
         }
 
+        protected override void OnLoop()
+        {
+            foreach (Tween tween in this.tweens)
+            {
+                if (this.loopType == LoopType.PingPong || this.loopType == LoopType.PingPongWithDelay) {
+                    tween.reversed = !tween.reversed;
+                }
+
+                tween.elapsed = 0.0f;
+                tween.Animate();
+            }
+        }
+
         protected override void OnComplete()
         {
             foreach (Tween tween in this.tweens)