Merge pull request IFTTT#1686 from IFTTT/optimize-filmstrip

Optimize filmstrip

Author: lauraskelton

Example/Podfile.lock

@@ -1,6 +1,6 @@
 PODS:
   - Expecta (1.0.0)
-  - JazzHands (2.0.1)
+  - JazzHands (2.0.2)
   - Specta (1.0.2)
 
 DEPENDENCIES:
@@ -14,7 +14,7 @@ EXTERNAL SOURCES:
 
 SPEC CHECKSUMS:
   Expecta: 32604574add2c46a36f8d2f716b6c5736eb75024
-  JazzHands: 100607fd6de21a830a2028122615098cda3407c3
+  JazzHands: 088a3949e539480b07ba6ae4877da935efcc061b
   Specta: 9cec98310dca411f7c7ffd6943552b501622abfe
 
 COCOAPODS: 0.37.2

Example/Pods/Local Podspecs/JazzHands.podspec.json

@@ -1,6 +1,6 @@
 Pod::Spec.new do |s|
   s.name         = 'JazzHands'
-  s.version      = '2.0.1'
+  s.version      = '2.0.2'
   s.summary      = 'Simple keyframe animations for scrolling intros.'
   s.homepage     = 'https://github.com/IFTTT/JazzHands'
   s.author       = { 

Example/Pods/Manifest.lock

@@ -17,18 +17,12 @@ @interface IFTTTKeyframe : NSObject
 @property (nonatomic, strong) id<IFTTTInterpolatable> value;
 @property (nonatomic, copy) IFTTTEasingFunction easingFunction;
 
-- (instancetype)initWithTime:(CGFloat)time value:(id)value;
 - (instancetype)initWithTime:(CGFloat)time value:(id)value easingFunction:(IFTTTEasingFunction)easingFunction;
 
 @end
 
 @implementation IFTTTKeyframe
 
-- (instancetype)initWithTime:(CGFloat)time value:(id)value
-{
-    return [self initWithTime:time value:value easingFunction:IFTTTEasingFunctionLinear];
-}
-
 - (instancetype)initWithTime:(CGFloat)time value:(id)value easingFunction:(IFTTTEasingFunction)easingFunction
 {
     if ((self = [super init])) {
@@ -66,15 +60,15 @@ - (BOOL)isEmpty
 
 - (void)setValue:(id<IFTTTInterpolatable>)value atTime:(CGFloat)time
 {
-    NSUInteger indexAfter = [self indexOfKeyframeAfterTime:time];
-    IFTTTKeyframe *newKeyframe = [[IFTTTKeyframe alloc] initWithTime:time value:value];
-    [self.keyframes insertObject:newKeyframe atIndex:indexAfter];
+    [self setValue:value atTime:time withEasingFunction:IFTTTEasingFunctionLinear];
 }
 
 - (void)setValue:(id<IFTTTInterpolatable>)value atTime:(CGFloat)time withEasingFunction:(IFTTTEasingFunction)easingFunction
 {
-    NSUInteger indexAfter = [self indexOfKeyframeAfterTime:time];
+    NSAssert([self canInterpolateNewValue:value], @"New value must have the same interpolatable type as existing keyframe values.");
+    
     IFTTTKeyframe *newKeyframe = [[IFTTTKeyframe alloc] initWithTime:time value:value easingFunction:easingFunction];
+    NSUInteger indexAfter = [self indexOfKeyframeAfterTime:time];
     [self.keyframes insertObject:newKeyframe atIndex:indexAfter];
 }
 
@@ -89,14 +83,7 @@ - (void)setValue:(id<IFTTTInterpolatable>)value atTime:(CGFloat)time withEasingF
         IFTTTKeyframe *keyframeBefore = (IFTTTKeyframe *)self.keyframes[indexAfter - 1];
         IFTTTKeyframe *keyframeAfter = (IFTTTKeyframe *)self.keyframes[indexAfter];
         CGFloat progress = [self progressFromTime:keyframeBefore.time toTime:keyframeAfter.time atTime:time withEasingFunction:keyframeBefore.easingFunction];
-        if ([keyframeBefore.value respondsToSelector:@selector(interpolateTo:withProgress:)]
-            && ([keyframeAfter.value isKindOfClass:[keyframeBefore.value class]]
-                || ([keyframeBefore.value isKindOfClass:[UIColor class]]
-                    && [keyframeAfter.value isKindOfClass:[UIColor class]]))) {
-            value = [keyframeBefore.value interpolateTo:keyframeAfter.value withProgress:progress];
-        } else {
-            value = keyframeBefore.value;
-        }
+        value = [keyframeBefore.value interpolateTo:keyframeAfter.value withProgress:progress];
     } else {
         value = ((IFTTTKeyframe *)self.keyframes.lastObject).value;
     }
@@ -122,4 +109,18 @@ - (CGFloat)progressFromTime:(CGFloat)fromTime toTime:(CGFloat)toTime atTime:(CGF
     return easingFunction(timeElapsed / duration);
 }
 
+- (BOOL)canInterpolateNewValue:(id)newValue
+{
+    if (self.keyframes.count == 0) {
+        return YES;
+    }
+    
+    IFTTTKeyframe *existingKeyframe = (IFTTTKeyframe *)self.keyframes.firstObject;
+    
+    return ([newValue respondsToSelector:@selector(interpolateTo:withProgress:)]
+            && ([newValue isKindOfClass:[existingKeyframe.value class]]
+                || ([existingKeyframe.value isKindOfClass:[UIColor class]]
+                    && [newValue isKindOfClass:[UIColor class]])));
+}
+
 @end