feat(iOS): enable dampingRatio and springVelocity

apidoc/Titanium/UI/Animation.yml

@@ -106,6 +106,16 @@ properties:
     constants: Titanium.UI.ANIMATION_CURVE_*
     platforms: [android, iphone, ipad]
     since: { android: "8.0.0", iphone: "0.9", ipad: "0.9" }
+
+  - name: dampingRatio
+    summary: |
+        The damping ratio for the spring animation as it approaches its quiescent state.
+    description: |
+        Use a value between 0 and 1. For a smoother deceleration use values closer to 1.
+        To increase oscillation use value closer to 0.
+    type: Number
+    platforms: [iphone, ipad]
+    since: "8.1.0"
 
   - name: delay
     summary: Delay, in milliseconds before starting the animation.
@@ -142,6 +152,17 @@ properties:
   - name: right
     summary: Value of the `right` property at the end of the animation.
     type: Number
+
+  - name: springVelocity
+    summary: The initial spring velocity.
+    description: |
+        For smooth start to the animation, match this value to the velocity of view as it was prior to attachment.
+        A value of 1 corresponds to the total animation distance traversed in one second. 
+        For example, if the total animation distance is 200 points and you want the start of the 
+        animation to match a view velocity of 100 pt/s, use a value of 0.5.
+    type: Number
+    platforms: [iphone, ipad]
+    since: "8.1.0"
 
   - name: top
     summary: Value of the `top` property at the end of the animation.

iphone/TitaniumKit/TitaniumKit/Sources/API/TiAnimation.h

@@ -83,6 +83,8 @@
   NSNumber *transition;
   TiViewProxy *view;
   TiViewProxy *animatedViewProxy;
+  NSNumber *dampingRatio;
+  NSNumber *springVelocity;
 
   // this is a temporary function passed in
   ListenerEntry *callback;
@@ -133,6 +135,8 @@
 @property (nonatomic, retain, readwrite) TiProxy *transform;
 @property (nonatomic, retain, readwrite) NSNumber *transition;
 @property (nonatomic, retain, readwrite) TiProxy *view;
+@property (nonatomic, retain, readwrite) NSNumber *dampingRatio;
+@property (nonatomic, retain, readwrite) NSNumber *springVelocity;
 
 + (TiAnimation *)animationFromArg:(id)args context:(id<TiEvaluator>)context create:(BOOL)yn;
 

iphone/TitaniumKit/TitaniumKit/Sources/API/TiAnimation.m

@@ -23,7 +23,7 @@ @implementation TiAnimation
 @synthesize delegate;
 @synthesize zIndex, left, right, top, bottom, width, height;
 @synthesize duration, color, backgroundColor, opacity, opaque, view;
-@synthesize visible, curve, repeat, autoreverse, delay, transform, transition;
+@synthesize visible, curve, repeat, autoreverse, delay, transform, transition, dampingRatio, springVelocity;
 @synthesize animatedView, callback, isReverse, reverseAnimation, resetState;
 
 - (id)initWithDictionary:(NSDictionary *)properties context:(id<TiEvaluator>)context_ callback:(KrollCallback *)callback_
@@ -95,6 +95,8 @@ - (id)initWithDictionary:(NSDictionary *)properties context:(id<TiEvaluator>)con
     SET_FLOAT_PROP(duration, properties);
     SET_FLOAT_PROP(opacity, properties);
     SET_FLOAT_PROP(delay, properties);
+    SET_FLOAT_PROP(dampingRatio, properties);
+    SET_FLOAT_PROP(springVelocity, properties);
     SET_INT_PROP(curve, properties);
     SET_INT_PROP(repeat, properties);
     SET_BOOL_PROP(visible, properties);
@@ -153,6 +155,8 @@ - (void)dealloc
   RELEASE_TO_NIL(transition);
   RELEASE_TO_NIL(callback);
   RELEASE_TO_NIL(view);
+  RELEASE_TO_NIL(dampingRatio);
+  RELEASE_TO_NIL(springVelocity);
   [animatedViewProxy release];
   [super dealloc];
 }
@@ -414,6 +418,10 @@ - (void)animate:(id)args
         [reverseAnimation setIsReverse:YES];
         [reverseAnimation setDuration:duration];
         [reverseAnimation setDelay:[NSNumber numberWithInt:0]];
+        if (dampingRatio != nil || springVelocity != nil) {
+          [reverseAnimation setDampingRatio:dampingRatio];
+          [reverseAnimation setSpringVelocity:springVelocity];
+        }
         switch ([curve intValue]) {
         case UIViewAnimationOptionCurveEaseIn:
           [reverseAnimation setCurve:[NSNumber numberWithInt:UIViewAnimationOptionCurveEaseOut]];
@@ -616,12 +624,22 @@ - (void)animate:(id)args
         [self animationCompleted:[self description] finished:[NSNumber numberWithBool:finished] context:self];
       }
     };
+    if (dampingRatio != nil || springVelocity != nil) {
+      [UIView animateWithDuration:animationDuration
+                            delay:([delay doubleValue] / 1000)
+           usingSpringWithDamping:[dampingRatio floatValue]
+            initialSpringVelocity:[springVelocity floatValue]
+                          options:options
+                       animations:animation
+                       completion:complete];
+    } else {
+      [UIView animateWithDuration:animationDuration
+                            delay:([delay doubleValue] / 1000)
+                          options:options
+                       animations:animation
+                       completion:complete];
+    }
 
-    [UIView animateWithDuration:animationDuration
-                          delay:([delay doubleValue] / 1000)
-                        options:options
-                     animations:animation
-                     completion:complete];
   } else {
     BOOL perform = YES;