Forward touch events to either the node or super

`_ASDisplayView` now forwards touch events to either super or it's node, depending on whether or not the node implements the methods.

fixes #199

AsyncDisplayKit/ASDisplayNode.mm

@@ -118,6 +118,21 @@ void ASDisplayNodePerformBlockOnMainThread(void (^block)())
   _flags.implementsDrawParameters = ([self respondsToSelector:@selector(drawParametersForAsyncLayer:)] ? 1 : 0);
 
   _fadeAnimationDuration = 0.1;
+
+  ASDisplayNodeMethodOverrides overrides = ASDisplayNodeMethodOverrideNone;
+  if (ASDisplayNodeSubclassOverridesSelector([self class], @selector(touchesBegan:withEvent:))) {
+    overrides |= ASDisplayNodeMethodOverrideTouchesBegan;
+  }
+  if (ASDisplayNodeSubclassOverridesSelector([self class], @selector(touchesMoved:withEvent:))) {
+    overrides |= ASDisplayNodeMethodOverrideTouchesMoved;
+  }
+  if (ASDisplayNodeSubclassOverridesSelector([self class], @selector(touchesCancelled:withEvent:))) {
+    overrides |= ASDisplayNodeMethodOverrideTouchesCancelled;
+  }
+  if (ASDisplayNodeSubclassOverridesSelector([self class], @selector(touchesEnded:withEvent:))) {
+    overrides |= ASDisplayNodeMethodOverrideTouchesEnded;
+  }
+  _methodOverrides = overrides;
 }
 
 - (id)init
@@ -1303,50 +1318,22 @@ static NSInteger incrementIfFound(NSInteger i) {
 
 - (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
 {
-  ASDisplayNodeAssertMainThread();
-
-  if (!_view)
-    return;
-
-  // If we reach the base implementation, forward up the view hierarchy.
-  UIView *superview = _view.superview;
-  [superview touchesBegan:touches withEvent:event];
+    // subclass hook
 }
 
 - (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
 {
-  ASDisplayNodeAssertMainThread();
-
-  if (!_view)
-    return;
-
-  // If we reach the base implementation, forward up the view hierarchy.
-  UIView *superview = _view.superview;
-  [superview touchesMoved:touches withEvent:event];
+    // subclass hook
 }
 
 - (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
 {
-  ASDisplayNodeAssertMainThread();
-
-  if (!_view)
-    return;
-
-  // If we reach the base implementation, forward up the view hierarchy.
-  UIView *superview = _view.superview;
-  [superview touchesEnded:touches withEvent:event];
+    // subclass hook
 }
 
 - (void)touchesCancelled:(NSSet *)touches withEvent:(UIEvent *)event
 {
-  ASDisplayNodeAssertMainThread();
-
-  if (!_view)
-    return;
-
-  // If we reach the base implementation, forward up the view hierarchy.
-  UIView *superview = _view.superview;
-  [superview touchesCancelled:touches withEvent:event];
+    // subclass hook
 }
 
 - (BOOL)gestureRecognizerShouldBegin:(UIGestureRecognizer *)gestureRecognizer

AsyncDisplayKit/Details/_ASDisplayView.mm

@@ -151,26 +151,38 @@
 #pragma mark - Event Handling + UIResponder Overrides
 - (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
 {
-  [super touchesBegan:touches withEvent:event];
-  [_node touchesBegan:touches withEvent:event];
+    if (_node.methodOverrides & ASDisplayNodeMethodOverrideTouchesBegan) {
+        [_node touchesBegan:touches withEvent:event];
+    } else {
+        [super touchesBegan:touches withEvent:event];
+    }
 }
 
 - (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
 {
-  [super touchesMoved:touches withEvent:event];
-  [_node touchesMoved:touches withEvent:event];
+    if (_node.methodOverrides & ASDisplayNodeMethodOverrideTouchesMoved) {
+        [_node touchesMoved:touches withEvent:event];
+    } else {
+        [super touchesMoved:touches withEvent:event];
+    }
 }
 
 - (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
 {
-  [super touchesEnded:touches withEvent:event];
-  [_node touchesEnded:touches withEvent:event];
+    if (_node.methodOverrides & ASDisplayNodeMethodOverrideTouchesEnded) {
+        [_node touchesEnded:touches withEvent:event];
+    } else {
+        [super touchesEnded:touches withEvent:event];
+    }
 }
 
 - (void)touchesCancelled:(NSSet *)touches withEvent:(UIEvent *)event
 {
-  [super touchesCancelled:touches withEvent:event];
-  [_node touchesCancelled:touches withEvent:event];
+    if (_node.methodOverrides & ASDisplayNodeMethodOverrideTouchesCancelled) {
+        [_node touchesCancelled:touches withEvent:event];
+    } else {
+        [super touchesCancelled:touches withEvent:event];
+    }
 }
 
 - (UIView *)hitTest:(CGPoint)point withEvent:(UIEvent *)event

AsyncDisplayKit/Private/ASDisplayNodeInternal.h

@@ -22,6 +22,14 @@ BOOL ASDisplayNodeSubclassOverridesSelector(Class subclass, SEL selector);
 CGFloat ASDisplayNodeScreenScale();
 void ASDisplayNodePerformBlockOnMainThread(void (^block)());
 
+typedef NS_OPTIONS(NSUInteger, ASDisplayNodeMethodOverrides) {
+  ASDisplayNodeMethodOverrideNone = 0,
+  ASDisplayNodeMethodOverrideTouchesBegan     = 1 << 0,
+  ASDisplayNodeMethodOverrideTouchesCancelled = 1 << 1,
+  ASDisplayNodeMethodOverrideTouchesEnded     = 1 << 2,
+  ASDisplayNodeMethodOverrideTouchesMoved     = 1 << 3
+};
+
 @class _ASPendingState;
 
 // Allow 2^n increments of begin disabling hierarchy notifications
@@ -102,6 +110,9 @@ void ASDisplayNodePerformBlockOnMainThread(void (^block)());
 // Creates a pendingViewState if one doesn't exist. Allows setting view properties on a bg thread before there is a view.
 @property (atomic, retain, readonly) _ASPendingState *pendingViewState;
 
+// Bitmask to check which methods an object overrides.
+@property (nonatomic, assign, readonly) ASDisplayNodeMethodOverrides methodOverrides;
+
 // Swizzle to extend the builtin functionality with custom logic
 - (BOOL)__shouldLoadViewOrLayer;
 - (BOOL)__shouldSize;