Added finished parameter in KFVectorLayer?s animationDidStopBlock

Summary:
I just added finished parameter to the animationDidStopBlock to be sure, animation was really finished (because this block is called at least twice).
Closes #77

Differential Revision: D4365439

Pulled By: LazyChild

fbshipit-source-id: 06939a5bdd921777c65ed9e061632817d205aa78

Author: renyu-io

ios/keyframes/src/Layers/KFVectorLayer.h

@@ -24,7 +24,7 @@
 
 @property (strong, nonatomic) KFVector *faceModel;
 @property (copy, nonatomic) NSDictionary<NSString *, UIImage *> *imageAssets;
-@property (copy, nonatomic) void (^animationDidStopBlock)(void);
+@property (copy, nonatomic) void (^animationDidStopBlock)(BOOL finished);
 
 /**
  * Path based face view initially starts off with frame stuck at 0.

ios/keyframes/src/Layers/KFVectorLayer.m

@@ -19,7 +19,8 @@
 #import "KFVectorFeatureLayer.h"
 #import "KFVectorGradientFeatureLayer.h"
 
-@implementation KFVectorLayer {
+@implementation KFVectorLayer
+{
   CALayer *_containerLayer;
   CABasicAnimation *_mockAnimation;
 }
@@ -165,17 +166,23 @@ - (void)_setupFace:(KFVector *)vector
   }];
 
   // 6) Add a mock animation for invoking stop callback.
-  _mockAnimation = [CABasicAnimation animationWithKeyPath:@"hidden"];
-  _mockAnimation.fromValue = @(NO);
-  _mockAnimation.toValue = @(NO);
-  _mockAnimation.duration = vector.animationFrameCount * 1.0 / vector.frameRate;
-  _mockAnimation.repeatCount = 1;
-  _mockAnimation.delegate = self;
-  [_mockAnimation setValue:@"mock animation" forKey:@"animationKey"];
+  _mockAnimation = [self _createMockAnimation];
 
   [self _resetAnimations];
 }
 
+- (CABasicAnimation *)_createMockAnimation
+{
+  CABasicAnimation *mockAnimation = [CABasicAnimation animationWithKeyPath:@"hidden"];
+  mockAnimation.fromValue = @(NO);
+  mockAnimation.toValue = @(NO);
+  mockAnimation.duration = _faceModel.animationFrameCount * 1.0 / _faceModel.frameRate;
+  mockAnimation.repeatCount = 1;
+  mockAnimation.delegate = self;
+  [mockAnimation setValue:@"mock animation" forKey:@"animationKey"];
+  return mockAnimation;
+}
+
 - (void)_resetAnimations
 {
   self.speed = 0;
@@ -236,10 +243,15 @@ - (void)layoutSublayers
 
 #pragma mark - CAAnimationDelegate
 
-- (void)animationDidStop:(CAAnimation *)anim finished:(BOOL)flag
+- (void)animationDidStop:(CAAnimation *)anim finished:(BOOL)finished
 {
   if ([anim valueForKey:@"animationKey"] == [_mockAnimation valueForKey:@"animationKey"] && _animationDidStopBlock) {
-    _animationDidStopBlock();
+    _animationDidStopBlock(finished);
+  }
+  if (finished) {
+    // Recreating mock animation for invoking stop callback again
+    _mockAnimation = [self _createMockAnimation];
+    [self addAnimation:_mockAnimation forKey:[_mockAnimation valueForKey:@"animationKey"]];
   }
 }