[0.73-stable] Add mouse hover events to RCTTextView

packages/react-native/Libraries/Text/Text/RCTTextShadowView.mm

@@ -85,16 +85,24 @@ - (void)uiManagerWillPerformMounting
 
   NSNumber *tag = self.reactTag;
   NSMutableArray<NSNumber *> *descendantViewTags = [NSMutableArray new];
-  [textStorage enumerateAttribute:RCTBaseTextShadowViewEmbeddedShadowViewAttributeName
-                          inRange:NSMakeRange(0, textStorage.length)
-                          options:0
-                       usingBlock:^(RCTShadowView *shadowView, NSRange range, __unused BOOL *stop) {
-                         if (!shadowView) {
-                           return;
-                         }
+  NSMutableArray<NSNumber *> *virtualSubviewTags = [NSMutableArray new]; // [macOS]
+
+// [macOS - Enumerate embedded shadow views and virtual subviews in one loop
+  [textStorage enumerateAttributesInRange:NSMakeRange(0, textStorage.length)
+                                  options:0
+                               usingBlock:^(NSDictionary<NSAttributedStringKey, id> *_Nonnull attrs, NSRange range, __unused BOOL * _Nonnull stop) {
+    id embeddedViewAttribute = attrs[RCTBaseTextShadowViewEmbeddedShadowViewAttributeName];
+    if ([embeddedViewAttribute isKindOfClass:[RCTShadowView class]]) {
+      RCTShadowView *embeddedShadowView = (RCTShadowView *)embeddedViewAttribute;
+      [descendantViewTags addObject:embeddedShadowView.reactTag];
+    }
 
-                         [descendantViewTags addObject:shadowView.reactTag];
-                       }];
+    id tagAttribute = attrs[RCTTextAttributesTagAttributeName];
+    if ([tagAttribute isKindOfClass:[NSNumber class]] && ![tagAttribute isEqualToNumber:tag]) {
+      [virtualSubviewTags addObject:tagAttribute];
+    }
+  }];
+// macOS]
 
   [_bridge.uiManager addUIBlock:^(RCTUIManager *uiManager, NSDictionary<NSNumber *, RCTUIView *> *viewRegistry) { // [macOS]
     RCTTextView *textView = (RCTTextView *)viewRegistry[tag];
@@ -113,11 +121,25 @@ - (void)uiManagerWillPerformMounting
           [descendantViews addObject:descendantView];
         }];
 
+// [macOS
+    NSMutableArray<RCTVirtualTextView *> *virtualSubviews = [NSMutableArray arrayWithCapacity:virtualSubviewTags.count];
+    [virtualSubviewTags
+        enumerateObjectsUsingBlock:^(NSNumber *_Nonnull virtualSubviewTag, NSUInteger index, BOOL *_Nonnull stop) {
+          RCTPlatformView *virtualSubview = viewRegistry[virtualSubviewTag];
+          if ([virtualSubview isKindOfClass:[RCTVirtualTextView class]]) {
+            [virtualSubviews addObject:(RCTVirtualTextView *)virtualSubview];
+          }
+        }];
+// macOS]
+
     // Removing all references to Shadow Views to avoid unnecessary retaining.
     [textStorage removeAttribute:RCTBaseTextShadowViewEmbeddedShadowViewAttributeName
                            range:NSMakeRange(0, textStorage.length)];
 
-    [textView setTextStorage:textStorage contentFrame:contentFrame descendantViews:descendantViews];
+    [textView setTextStorage:textStorage
+                contentFrame:contentFrame
+             descendantViews:descendantViews
+             virtualSubviews:virtualSubviews]; // [macOS]
   }];
 }
 

packages/react-native/Libraries/Text/Text/RCTTextView.h

@@ -7,6 +7,7 @@
 
 #import <React/RCTComponent.h>
 #import <React/RCTEventDispatcher.h> // [macOS]
+#import <React/RCTVirtualTextView.h> // [macOS]
 
 #import <React/RCTUIKit.h> // [macOS]
 
@@ -22,6 +23,13 @@ NS_ASSUME_NONNULL_BEGIN
           contentFrame:(CGRect)contentFrame
        descendantViews:(NSArray<RCTPlatformView *> *)descendantViews; // [macOS]
 
+// [macOS
+- (void)setTextStorage:(NSTextStorage *)textStorage
+          contentFrame:(CGRect)contentFrame
+       descendantViews:(NSArray<RCTPlatformView *> *)descendantViews
+       virtualSubviews:(NSArray<RCTVirtualTextView *> *_Nullable)virtualSubviews;
+// macOS]
+
 #if TARGET_OS_OSX // [macOS
 - (NSRect)getRectForCharRange:(NSRange)charRange;
 #endif // macOS]

packages/react-native/Libraries/Text/Text/RCTTextView.mm

@@ -12,6 +12,7 @@
 #endif // [macOS]
 
 #import <React/RCTAssert.h> // [macOS]
+#import <React/RCTUIManager.h> // [macOS]
 #import <React/RCTUtils.h>
 #import <React/UIView+React.h>
 #import <React/RCTFocusChangeEvent.h> // [macOS]
@@ -62,6 +63,8 @@ @implementation RCTTextView {
 
   id<RCTEventDispatcherProtocol> _eventDispatcher; // [macOS]
   NSArray<RCTUIView *> *_Nullable _descendantViews; // [macOS]
+  NSArray<RCTVirtualTextView *> *_Nullable _virtualSubviews; // [macOS]
+  RCTUIView *_Nullable _currentHoveredSubview; // [macOS]
   NSTextStorage *_Nullable _textStorage;
   CGRect _contentFrame;
 }
@@ -99,6 +102,7 @@ - (instancetype)initWithFrame:(CGRect)frame
     _textView.layoutManager.usesFontLeading = NO;
     _textStorage = _textView.textStorage;
     [self addSubview:_textView];
+    _currentHoveredSubview = nil;
 #endif // macOS]
     RCTUIViewSetContentModeRedraw(self); // [macOS]
   }
@@ -162,6 +166,20 @@ - (void)setTextStorage:(NSTextStorage *)textStorage
           contentFrame:(CGRect)contentFrame
        descendantViews:(NSArray<RCTPlatformView *> *)descendantViews // [macOS]
 {
+  // [macOS - to keep track of virtualSubviews as well
+  [self setTextStorage:textStorage
+          contentFrame:contentFrame
+       descendantViews:descendantViews
+       virtualSubviews:nil];
+}
+
+- (void)setTextStorage:(NSTextStorage *)textStorage
+          contentFrame:(CGRect)contentFrame
+       descendantViews:(NSArray<RCTPlatformView *> *)descendantViews
+       virtualSubviews:(NSArray<RCTVirtualTextView *> *)virtualSubviews
+{
+  // macOS]
+
   // This lets the textView own its text storage on macOS
   // We update and replace the text container `_textView.textStorage.attributedString` when text/layout changes
 #if !TARGET_OS_OSX // [macOS]
@@ -204,6 +222,8 @@ - (void)setTextStorage:(NSTextStorage *)textStorage
     [self addSubview:view];
   }
 
+  _virtualSubviews = virtualSubviews; // [macOS]
+
   [self setNeedsDisplay];
 }
 
@@ -414,6 +434,21 @@ - (void)handleLongPress:(UILongPressGestureRecognizer *)gesture
 }
 #else // [macOS
 
+- (BOOL)hasMouseHoverEvent
+{
+  if ([super hasMouseHoverEvent]) {
+    return YES;
+  }
+
+  // We only care about virtual subviews here.
+  // Embedded views (e.g., <Text> <View /> </Text>) handle mouse hover events themselves.
+  NSUInteger indexOfChildWithMouseHoverEvent = [_virtualSubviews indexOfObjectPassingTest:^BOOL(RCTVirtualTextView *_Nonnull childView, NSUInteger idx, BOOL *_Nonnull stop) {
+    *stop = [childView hasMouseHoverEvent];
+    return *stop;
+  }];
+  return indexOfChildWithMouseHoverEvent != NSNotFound;
+}
+
 - (NSView *)hitTest:(NSPoint)point
 {
   // We will forward mouse click events to the NSTextView ourselves to prevent NSTextView from swallowing events that may be handled in JS (e.g. long press).
@@ -428,6 +463,110 @@ - (NSView *)hitTest:(NSPoint)point
   return isTextViewClick ? self : hitView;
 }
 
+- (NSNumber *)reactTagAtMouseLocationFromEvent:(NSEvent *)event
+{
+  NSPoint locationInSelf = [self convertPoint:event.locationInWindow fromView:nil];
+  NSPoint locationInInnerTextView = [self convertPoint:locationInSelf toView:_textView]; // This is needed if the parent <Text> view has padding
+  return [self reactTagAtPoint:locationInInnerTextView];
+}
+
+- (void)mouseEntered:(NSEvent *)event
+{
+  // superclass invokes self.onMouseEnter, so do this first
+  [super mouseEntered:event];
+
+  [self updateHoveredSubviewWithEvent:event];
+}
+
+- (void)mouseExited:(NSEvent *)event
+{
+  [self updateHoveredSubviewWithEvent:event];
+
+  // superclass invokes self.onMouseLeave, so do this last
+  [super mouseExited:event];
+}
+
+- (void)mouseMoved:(NSEvent *)event
+{
+  [super mouseMoved:event];
+  [self updateHoveredSubviewWithEvent:event];
+}
+
+- (void)updateHoveredSubviewWithEvent:(NSEvent *)event
+{
+  RCTUIView *hoveredView = nil;
+
+  if ([event type] != NSEventTypeMouseExited && _virtualSubviews != nil) {
+    NSNumber *reactTagOfHoveredView = [self reactTagAtMouseLocationFromEvent:event];
+
+    if (reactTagOfHoveredView == nil) {
+      // This happens if we hover over an embedded view, which will handle its own mouse events
+      return;
+    }
+
+    if ([reactTagOfHoveredView isEqualToNumber:self.reactTag]) {
+      // We're hovering over the root Text element
+      hoveredView = self;
+    } else {
+      // Maybe we're hovering over a child Text element?
+      NSUInteger index = [_virtualSubviews indexOfObjectPassingTest:^BOOL(RCTVirtualTextView *_Nonnull view, NSUInteger idx, BOOL *_Nonnull stop) {
+        *stop = [[view reactTag] isEqualToNumber:reactTagOfHoveredView];
+        return *stop;
+      }];
+      if (index != NSNotFound) {
+        hoveredView = _virtualSubviews[index];
+      }
+    }
+  }
+
+  if (_currentHoveredSubview == hoveredView) {
+    return;
+  }
+
+  // self will always be an ancestor of any views we pass in here, so it serves as a good default option.
+  // Also, if we do set from/to nil, we have to call the relevant events on the entire subtree.
+  RCTUIManager *uiManager = [[_eventDispatcher bridge] uiManager];
+  RCTShadowView *oldShadowView = [uiManager shadowViewForReactTag:[(_currentHoveredSubview ?: self) reactTag]];
+  RCTShadowView *newShadowView = [uiManager shadowViewForReactTag:[(hoveredView ?: self) reactTag]];
+
+  // Find the common ancestor between the two shadow views
+  RCTShadowView *commonAncestor = [oldShadowView ancestorSharedWithShadowView:newShadowView];
+
+  for (RCTShadowView *exitedShadowView = oldShadowView; exitedShadowView != commonAncestor && exitedShadowView != nil; exitedShadowView = [exitedShadowView reactSuperview]) {
+    RCTPlatformView *exitedView = [uiManager viewForReactTag:[exitedShadowView reactTag]];
+    if (![exitedView isKindOfClass:[RCTUIView class]]) {
+      RCTLogError(@"Unexpected view of type %@ found in hierarchy, must be RCTUIView or subclass", [exitedView class]);
+      continue;
+    }
+
+    RCTUIView *exitedReactView = (RCTUIView *)exitedView;
+    [self sendMouseEventWithBlock:[exitedReactView onMouseLeave]
+                     locationInfo:[self locationInfoFromEvent:event]
+                    modifierFlags:event.modifierFlags
+                   additionalData:nil];
+  }
+
+  // We cache these so we can call them from outermost to innermost
+  NSMutableArray<RCTUIView *> *enteredViewHierarchy = [NSMutableArray new];
+  for (RCTShadowView *enteredShadowView = newShadowView; enteredShadowView != commonAncestor && enteredShadowView != nil; enteredShadowView = [enteredShadowView reactSuperview]) {
+    RCTPlatformView *enteredView = [uiManager viewForReactTag:[enteredShadowView reactTag]];
+    if (![enteredView isKindOfClass:[RCTUIView class]]) {
+      RCTLogError(@"Unexpected view of type %@ found in hierarchy, must be RCTUIView or subclass", [enteredView class]);
+      continue;
+    }
+
+    [enteredViewHierarchy addObject:(RCTUIView *)enteredView];
+  }
+  for (NSInteger i = [enteredViewHierarchy count] - 1; i >= 0; i--) {
+    [self sendMouseEventWithBlock:[[enteredViewHierarchy objectAtIndex:i] onMouseEnter]
+                     locationInfo:[self locationInfoFromEvent:event]
+                    modifierFlags:event.modifierFlags
+                   additionalData:nil];
+  }
+
+  _currentHoveredSubview = hoveredView;
+}
+
 - (void)rightMouseDown:(NSEvent *)event
 {
 

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

@@ -406,6 +406,7 @@ CGPathRef UIBezierPathCreateCGPathRef(UIBezierPath *path);
 - (void)setNeedsDisplay;
 
 // Methods related to mouse events
+- (BOOL)hasMouseHoverEvent;
 - (NSDictionary*)locationInfoFromDraggingLocation:(NSPoint)locationInWindow;
 - (NSDictionary*)locationInfoFromEvent:(NSEvent*)event;
 

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

@@ -217,6 +217,7 @@ @implementation RCTUIView
   BOOL _clipsToBounds;
   BOOL _hasMouseOver;
   BOOL _userInteractionEnabled;
+  NSTrackingArea *_trackingArea;
   BOOL _mouseDownCanMoveWindow;
 }
 
@@ -349,6 +350,13 @@ - (void)viewBoundsChanged:(NSNotification*)__unused inNotif
   }
 }
 
+- (BOOL)hasMouseHoverEvent
+{
+  // This can be overridden by subclasses as needed.
+  // e.g., RCTTextView, which consolidates its JS children into a single gigantic NSAttributedString
+  return self.onMouseEnter || self.onMouseLeave;
+}
+
 - (NSDictionary*)locationInfoFromDraggingLocation:(NSPoint)locationInWindow
 {
   NSPoint locationInView = [self convertPoint:locationInWindow fromView:nil];
@@ -425,6 +433,28 @@ - (void)sendMouseEventWithBlock:(RCTDirectEventBlock)block
   block(body);
 }
 
+- (void)updateTrackingAreas
+{
+  BOOL hasMouseHoverEvent = [self hasMouseHoverEvent];
+  BOOL wouldRecreateIdenticalTrackingArea = hasMouseHoverEvent && _trackingArea && NSEqualRects(self.bounds, [_trackingArea rect]);
+
+  if (!wouldRecreateIdenticalTrackingArea) {
+    if (_trackingArea) {
+      [self removeTrackingArea:_trackingArea];
+    }
+
+    if (hasMouseHoverEvent) {
+      _trackingArea = [[NSTrackingArea alloc] initWithRect:self.bounds
+                                                   options:NSTrackingActiveAlways|NSTrackingMouseEnteredAndExited
+                                                     owner:self
+                                                  userInfo:nil];
+      [self addTrackingArea:_trackingArea];
+    }
+  }
+
+  [super updateTrackingAreas];
+}
+
 - (BOOL)mouseDownCanMoveWindow{
 	return _mouseDownCanMoveWindow;
 }

packages/react-native/React/Views/RCTShadowView.h

@@ -241,6 +241,13 @@ typedef void (^RCTApplierBlock)(NSDictionary<NSNumber *, RCTPlatformView *> *vie
  */
 - (CGRect)measureLayoutRelativeToAncestor:(RCTShadowView *)ancestor;
 
+// [macOS
+/**
+ * Returns the closest ancestor shared by this shadow view and another specified shadow view.
+ */
+- (RCTShadowView *)ancestorSharedWithShadowView:(RCTShadowView *)shadowView;
+// macOS]
+
 /**
  * Checks if the current shadow view is a descendant of the provided `ancestor`
  */

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

@@ -182,6 +182,25 @@ - (CGRect)measureLayoutRelativeToAncestor:(RCTShadowView *)ancestor
   return (CGRect){offset, self.layoutMetrics.frame.size};
 }
 
+// [macOS
+- (RCTShadowView *)ancestorSharedWithShadowView:(RCTShadowView *)shadowView
+{
+  // TODO: Can this be optimized by climbing up both hierarchies at the same time?
+  NSMutableSet<RCTShadowView *> *selfSuperviews = [NSMutableSet set];
+  for (RCTShadowView *view = self; view != nil; view = [view reactSuperview]) {
+    [selfSuperviews addObject:view];
+  }
+
+  for (RCTShadowView *candidateView = shadowView; candidateView != nil; candidateView = [candidateView reactSuperview]) {
+    if ([selfSuperviews containsObject:candidateView]) {
+      return candidateView;
+    }
+  }
+
+  return nil;
+}
+// macOS]
+
 - (BOOL)viewIsDescendantOf:(RCTShadowView *)ancestor
 {
   RCTShadowView *shadowView = self;