Fix sequences completing too soon and not delaying

Author: adamgraham

Runtime/Sequence.cs

@@ -81,13 +81,23 @@ private void Next()
         {
             this.currentIndex++;
 
-            if (this.currentIndex >= this.tweens.Count) {
+            if (CanComplete()) {
                 Complete();
             } else {
                 this.tweens[this.currentIndex].Play();
             }
         }
 
+        protected override void Animate()
+        {
+            // Do nothing. The individual tweens are animated on their own.
+        }
+
+        protected override bool CanComplete()
+        {
+            return this.currentIndex >= this.tweens.Count;
+        }
+
         protected override void OnStart()
         {
             this.currentIndex = 0;
@@ -146,11 +156,6 @@ protected override void OnReset()
             this.currentIndex = -1;
         }
 
-        protected override void Animate()
-        {
-            // Do nothing. The individual tweens are animated on their own.
-        }
-
     }
 
 }

Runtime/Tween.cs

@@ -163,11 +163,7 @@ internal void Update(float deltaTime)
         {
             if (this.IsPlaying)
             {
-                if (this.elapsed >= this.duration)
-                {
-                    Complete();
-                }
-                else if (!this.IsDelayed)
+                if (!this.IsDelayed)
                 {
                     this.elapsed += deltaTime;
 
@@ -177,10 +173,21 @@ internal void Update(float deltaTime)
                     if (this.onUpdate != null) {
                         this.onUpdate.Invoke();
                     }
+
+                    if (CanComplete()) {
+                        Complete();
+                    }
                 }
                 else
                 {
                     this.delayElapsed += deltaTime;
+
+                    // Start the tween once the delay is complete and only if
+                    // the elapsed time is zero which indicates it has never
+                    // been updated yet
+                    if (this.elapsed == 0 && this.delayElapsed >= this.delay) {
+                        Start();
+                    }
                 }
             }
             else if (this.state == TweenState.Ready && this.autoStart)
@@ -213,15 +220,26 @@ public void Play()
                 this.elapsed = 0.0f;
                 this.delayElapsed = 0.0f;
 
-                OnStart();
-                Animate();
-
-                if (this.onStart != null) {
-                    this.onStart.Invoke();
+                // Start right away if there is no delay
+                if (!this.IsDelayed) {
+                    Start();
                 }
             }
         }
 
+        /// <summary>
+        /// Starts the tween for the first time.
+        /// </summary>
+        private void Start()
+        {
+            OnStart();
+            Animate();
+
+            if (this.onStart != null) {
+                this.onStart.Invoke();
+            }
+        }
+
         /// <summary>
         /// Stops the tween if currently being played.
         /// </summary>
@@ -327,6 +345,7 @@ internal void Reset()
             OnReset();
         }
 
+        protected virtual bool CanComplete() => this.elapsed >= this.duration;
         protected virtual void OnUpdate() {}
         protected virtual void OnStart() {}
         protected virtual void OnStop() {}

Runtime/Tweening.cs

@@ -52,7 +52,17 @@ public static class Tweening
         /// <summary>
         /// The number of tweens currently alive (not necessarily active).
         /// </summary>
-        public static int Count => TweenManager.Instance.tweens.Count;
+        public static int Count
+        {
+            get
+            {
+                if (TweenManager.HasInstance) {
+                    return TweenManager.Instance.tweens.Count;
+                } else {
+                    return 0;
+                }
+            }
+        }
 
         /// <summary>
         /// The number of tweens that are currently alive and active.
@@ -61,6 +71,10 @@ public static int ActiveCount
         {
             get
             {
+                if (!TweenManager.HasInstance) {
+                    return 0;
+                }
+
                 int count = 0;
                 List<Tween> tweens = TweenManager.Instance.tweens;