fix(0.76, macOS): reconcile coordinate systems for mouse events (#2403) (#2405)

Author: Saadnajmi

packages/react-native/React/Base/RCTTouchHandler.m

@@ -128,8 +128,9 @@ - (void)_recordNewTouches:(NSSet *)touches
 #else // [macOS
     // -[NSView hitTest:] takes coordinates in a view's superview coordinate system.
     // The assumption here is that a RCTUIView/RCTSurfaceView will always have a superview.
-    CGPoint touchLocation = [self.view.superview convertPoint:touch.locationInWindow fromView:nil];
-    NSView *targetView = [self.view hitTest:touchLocation];
+    NSView *superview = [[self view] superview];
+    const CGPoint touchLocationInSuperview = [superview convertPoint:touch.locationInWindow fromView:nil];
+    NSView *targetView = [self.view hitTest:touchLocationInSuperview];
     // Don't record clicks on scrollbars.
     if ([targetView isKindOfClass:[NSScroller class]]) {
       continue;
@@ -148,8 +149,7 @@ - (void)_recordNewTouches:(NSSet *)touches
     } else {
       _shouldSendMouseUpOnSystemBehalf = NO;
     }
-    touchLocation = [targetView convertPoint:touchLocation fromView:self.view.superview];
-    
+
     while (targetView) {
       BOOL isUserInteractionEnabled = NO;
       if ([((RCTUIView*)targetView) respondsToSelector:@selector(isUserInteractionEnabled)]) { // [macOS]
@@ -161,7 +161,8 @@ - (void)_recordNewTouches:(NSSet *)touches
       targetView = targetView.superview;
     }
 
-    NSNumber *reactTag = [targetView reactTagAtPoint:touchLocation];
+    const CGPoint touchLocationInSelf = [targetView convertPoint:touchLocationInSuperview fromView:self.view.superview];
+    NSNumber *reactTag = [targetView reactTagAtPoint:touchLocationInSelf];
     BOOL isUserInteractionEnabled = NO;
     if ([((RCTUIView*)targetView) respondsToSelector:@selector(isUserInteractionEnabled)]) { // [macOS]
       isUserInteractionEnabled = ((RCTUIView*)targetView).isUserInteractionEnabled; // [macOS]

packages/react-native/React/Base/RCTUIKit.h

@@ -486,7 +486,10 @@ CGPathRef UIBezierPathCreateCGPathRef(UIBezierPath *path);
 
 NS_INLINE RCTPlatformView *RCTUIViewHitTestWithEvent(RCTPlatformView *view, CGPoint point, __unused UIEvent *__nullable event)
 {
-  return [view hitTest:point];
+  // [macOS IMPORTANT -- point is in local coordinate space, but OSX expects super coordinate space for hitTest:
+  NSView *superview = [view superview];
+  NSPoint pointInSuperview = superview != nil ? [view convertPoint:point toView:superview] : point;
+  return [view hitTest:pointInSuperview];
 }
 
 BOOL RCTUIViewSetClipsToBounds(RCTPlatformView *view);

packages/react-native/React/Base/macOS/RCTUIKit.m

@@ -454,7 +454,10 @@ - (void)setTransform:(CGAffineTransform)transform
 
 - (NSView *)hitTest:(NSPoint)point
 {
-  return [self hitTest:NSPointToCGPoint(point) withEvent:nil];
+  // IMPORTANT point is passed in super coordinates by OSX, but expected to be passed in local coordinates
+  NSView *superview = [self superview];
+  NSPoint pointInSelf = superview != nil ? [self convertPoint:point fromView:superview] : point;
+  return [self hitTest:pointInSelf withEvent:nil];
 }
 
 - (BOOL)wantsUpdateLayer
@@ -505,7 +508,11 @@ - (BOOL)becomeFirstResponder
 
 - (NSView *)hitTest:(CGPoint)point withEvent:(__unused UIEvent *)event
 {
-  return self.userInteractionEnabled ? [super hitTest:NSPointFromCGPoint(point)] : nil;
+// [macOS
+  // IMPORTANT point is expected to be passed in local coordinates, but OSX expects point to be super 
+  NSView *superview = [self superview];
+  NSPoint pointInSuperview = superview != nil ? [self convertPoint:point toView:superview] : point;
+  return self.userInteractionEnabled ? [super hitTest:pointInSuperview] : nil;
 }
 
 - (BOOL)pointInside:(CGPoint)point withEvent:(__unused UIEvent *)event

packages/react-native/React/Views/RCTView.m

@@ -252,17 +252,8 @@ - (RCTPlatformView *)hitTest:(CGPoint)point withEvent:(UIEvent *)event // [macOS
     // of the hit view will return YES from -pointInside:withEvent:). See:
     //  - https://developer.apple.com/library/ios/qa/qa2013/qa1812.html
     for (RCTUIView *subview in [sortedSubviews reverseObjectEnumerator]) { // [macOS]
-      CGPoint pointForHitTest = CGPointZero; // [macOS
-#if !TARGET_OS_OSX // [macOS]
-      pointForHitTest = [subview convertPoint:point fromView:self];
-#else // [macOS
-      if ([subview isKindOfClass:[RCTView class]]) {
-        pointForHitTest = [subview convertPoint:point fromView:self];
-      } else {
-        pointForHitTest = point;
-      }
-#endif // macOS]
-      hitSubview = RCTUIViewHitTestWithEvent(subview, pointForHitTest, event); // macOS]
+      CGPoint pointForHitTest = [subview convertPoint:point fromView:self];
+      hitSubview = RCTUIViewHitTestWithEvent(subview, pointForHitTest, event); // [macOS]
       if (hitSubview != nil) {
         break;
       }

packages/react-native/React/Views/UIView+React.m

@@ -573,10 +573,13 @@ - (NSString *)react_recursiveDescription
 
 // [macOS
 #pragma mark - Hit testing
-#if TARGET_OS_OSX  
+#if TARGET_OS_OSX
+// IMPORTANT -- point is in local coordinate space, unlike the hitTest: version from OSX which is in super's coordinate space
 - (RCTPlatformView *)hitTest:(CGPoint)point withEvent:(UIEvent *)event
 {
-  return [self hitTest:point];
+  NSView *superview = [self superview];
+  NSPoint pointInSuper = superview != nil ? [self convertPoint:point toView:superview] : point;
+  return [self hitTest:pointInSuper];
 }
 #endif // macOS]