fix(ios): replace per-cell UITextView with single drawRect pass for tables

packages/react-native-enriched-markdown/ios/views/ENRMTableIOSGridView.h

@@ -0,0 +1,40 @@
+#pragma once
+
+#include <TargetConditionals.h>
+#if !TARGET_OS_OSX
+
+#import <UIKit/UIKit.h>
+
+NS_ASSUME_NONNULL_BEGIN
+
+typedef void (^ENRMTableIOSLinkBlock)(NSString *url);
+
+@interface ENRMTableIOSRowData : NSObject
+@property (nonatomic, strong) NSArray<NSAttributedString *> *cellTexts;
+@property (nonatomic, strong) UIColor *backgroundColor;
+@end
+
+/// Draws the entire table grid in a single drawRect: pass, avoiding
+/// per-cell UITextView allocation and the TextKit layout storms that
+/// cause multi-second main-thread hangs on large tables.
+@interface ENRMTableIOSGridView : UIView
+
+@property (nonatomic, copy, nullable) ENRMTableIOSLinkBlock onLinkTap;
+@property (nonatomic, copy, nullable) ENRMTableIOSLinkBlock onLinkLongTap;
+
+- (void)updateWithRows:(NSArray<ENRMTableIOSRowData *> *)rows
+             columnWidths:(NSArray<NSNumber *> *)columnWidths
+               rowHeights:(NSArray<NSNumber *> *)rowHeights
+              borderColor:(UIColor *)borderColor
+              borderWidth:(CGFloat)borderWidth
+    horizontalCellPadding:(CGFloat)horizontalCellPadding
+      verticalCellPadding:(CGFloat)verticalCellPadding
+             cornerRadius:(CGFloat)cornerRadius;
+
+- (void)fadeInRowsFrom:(NSUInteger)startRow duration:(NSTimeInterval)duration;
+
+@end
+
+NS_ASSUME_NONNULL_END
+
+#endif // !TARGET_OS_OSX

packages/react-native-enriched-markdown/ios/views/ENRMTableIOSGridView.m

@@ -0,0 +1,216 @@
+#import "ENRMTableIOSGridView.h"
+
+#if !TARGET_OS_OSX
+
+@implementation ENRMTableIOSRowData
+@end
+
+@implementation ENRMTableIOSGridView {
+  NSArray<ENRMTableIOSRowData *> *_tableRows;
+  NSArray<NSNumber *> *_columnWidths;
+  NSArray<NSNumber *> *_rowHeights;
+  UIColor *_borderColor;
+  CGFloat _borderWidth;
+  CGFloat _horizontalCellPadding;
+  CGFloat _verticalCellPadding;
+}
+
+- (instancetype)initWithFrame:(CGRect)frame
+{
+  self = [super initWithFrame:frame];
+  if (self) {
+    self.backgroundColor = [UIColor clearColor];
+    self.contentMode = UIViewContentModeRedraw;
+    self.opaque = NO;
+    self.accessibilityElementsHidden = YES;
+
+    UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(handleTap:)];
+    [self addGestureRecognizer:tap];
+
+    UILongPressGestureRecognizer *longPress =
+        [[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(handleLongPress:)];
+    [self addGestureRecognizer:longPress];
+  }
+  return self;
+}
+
+#pragma mark - Data
+
+- (void)updateWithRows:(NSArray<ENRMTableIOSRowData *> *)rows
+             columnWidths:(NSArray<NSNumber *> *)columnWidths
+               rowHeights:(NSArray<NSNumber *> *)rowHeights
+              borderColor:(UIColor *)borderColor
+              borderWidth:(CGFloat)borderWidth
+    horizontalCellPadding:(CGFloat)horizontalCellPadding
+      verticalCellPadding:(CGFloat)verticalCellPadding
+             cornerRadius:(CGFloat)cornerRadius
+{
+  _tableRows = [rows copy];
+  _columnWidths = [columnWidths copy];
+  _rowHeights = [rowHeights copy];
+  _borderColor = borderColor;
+  _borderWidth = borderWidth;
+  _horizontalCellPadding = horizontalCellPadding;
+  _verticalCellPadding = verticalCellPadding;
+  [self setNeedsDisplay];
+}
+
+- (void)fadeInRowsFrom:(NSUInteger)startRow duration:(NSTimeInterval)duration
+{
+  if (startRow >= _tableRows.count)
+    return;
+
+  [UIView transitionWithView:self
+                    duration:duration
+                     options:UIViewAnimationOptionTransitionCrossDissolve
+                  animations:^{}
+                  completion:nil];
+}
+
+#pragma mark - Drawing
+
+- (void)drawRect:(CGRect)dirtyRect
+{
+  if (!_tableRows.count || !_columnWidths.count || !_rowHeights.count)
+    return;
+
+  CGFloat yOffset = 0;
+  for (NSUInteger r = 0; r < _tableRows.count; r++) {
+    ENRMTableIOSRowData *rowData = _tableRows[r];
+    CGFloat rowHeight = [_rowHeights[r] doubleValue];
+    CGFloat xOffset = 0;
+
+    NSUInteger colCount = MIN(rowData.cellTexts.count, _columnWidths.count);
+    for (NSUInteger c = 0; c < colCount; c++) {
+      CGFloat columnWidth = [_columnWidths[c] doubleValue];
+      CGRect cellRect = CGRectMake(xOffset, yOffset, columnWidth + _borderWidth, rowHeight + _borderWidth);
+
+      [rowData.backgroundColor setFill];
+      UIRectFill(cellRect);
+
+      [_borderColor setStroke];
+      UIBezierPath *border = [UIBezierPath bezierPathWithRect:cellRect];
+      border.lineWidth = _borderWidth;
+      [border stroke];
+
+      NSAttributedString *text = rowData.cellTexts[c];
+      if (text.length > 0) {
+        CGRect textRect = CGRectMake(xOffset + _horizontalCellPadding, yOffset + _verticalCellPadding,
+                                     columnWidth - _horizontalCellPadding * 2, rowHeight - _verticalCellPadding * 2);
+        [text drawWithRect:textRect
+                   options:NSStringDrawingUsesLineFragmentOrigin | NSStringDrawingUsesFontLeading
+                   context:nil];
+      }
+
+      xOffset += columnWidth;
+    }
+    yOffset += rowHeight;
+  }
+}
+
+#pragma mark - Link hit-testing
+
+- (BOOL)cellAtPoint:(CGPoint)point
+          rowOrigin:(out CGFloat *)outRowY
+          rowHeight:(out CGFloat *)outRowH
+          colOrigin:(out CGFloat *)outColX
+           colWidth:(out CGFloat *)outColW
+           cellText:(out NSAttributedString *__autoreleasing *)outText
+{
+  CGFloat rowY = 0;
+  for (NSUInteger r = 0; r < _tableRows.count; r++) {
+    CGFloat rh = [_rowHeights[r] doubleValue];
+    if (point.y >= rowY && point.y < rowY + rh) {
+      CGFloat colX = 0;
+      for (NSUInteger c = 0; c < _columnWidths.count; c++) {
+        CGFloat cw = [_columnWidths[c] doubleValue];
+        if (point.x >= colX && point.x < colX + cw) {
+          ENRMTableIOSRowData *rowData = _tableRows[r];
+          if (c >= rowData.cellTexts.count)
+            return NO;
+          *outRowY = rowY;
+          *outRowH = rh;
+          *outColX = colX;
+          *outColW = cw;
+          *outText = rowData.cellTexts[c];
+          return YES;
+        }
+        colX += cw;
+      }
+      return NO;
+    }
+    rowY += rh;
+  }
+  return NO;
+}
+
+static NSString *linkInAttributedString(NSAttributedString *text, CGRect textRect, CGPoint point)
+{
+  if (text.length == 0)
+    return nil;
+
+  NSTextStorage *textStorage = [[NSTextStorage alloc] initWithAttributedString:text];
+  NSLayoutManager *layoutManager = [[NSLayoutManager alloc] init];
+  NSTextContainer *textContainer = [[NSTextContainer alloc] initWithSize:textRect.size];
+  textContainer.lineFragmentPadding = 0;
+  [layoutManager addTextContainer:textContainer];
+  [textStorage addLayoutManager:layoutManager];
+  [layoutManager ensureLayoutForTextContainer:textContainer];
+
+  CGPoint local = CGPointMake(point.x - textRect.origin.x, point.y - textRect.origin.y);
+  CGFloat fraction = 0;
+  NSUInteger glyphIndex = [layoutManager glyphIndexForPoint:local
+                                            inTextContainer:textContainer
+                             fractionOfDistanceThroughGlyph:&fraction];
+  if (glyphIndex >= layoutManager.numberOfGlyphs)
+    return nil;
+  NSUInteger charIndex = [layoutManager characterIndexForGlyphAtIndex:glyphIndex];
+  if (charIndex >= text.length)
+    return nil;
+
+  return [text attribute:@"linkURL" atIndex:charIndex effectiveRange:NULL];
+}
+
+- (NSString *)linkURLAtPoint:(CGPoint)point
+{
+  CGFloat rowY, rowH, colX, colW;
+  NSAttributedString *text;
+  if (![self cellAtPoint:point rowOrigin:&rowY rowHeight:&rowH colOrigin:&colX colWidth:&colW cellText:&text])
+    return nil;
+
+  CGRect textRect = CGRectMake(colX + _horizontalCellPadding, rowY + _verticalCellPadding,
+                               colW - _horizontalCellPadding * 2, rowH - _verticalCellPadding * 2);
+  if (!CGRectContainsPoint(textRect, point))
+    return nil;
+
+  return linkInAttributedString(text, textRect, point);
+}
+
+#pragma mark - Gesture handlers
+
+- (void)handleLinkGesture:(UIGestureRecognizer *)recognizer block:(ENRMTableIOSLinkBlock)block
+{
+  CGPoint point = [recognizer locationInView:self];
+  NSString *url = [self linkURLAtPoint:point];
+  if (url && block) {
+    block(url);
+  }
+}
+
+- (void)handleTap:(UITapGestureRecognizer *)recognizer
+{
+  if (recognizer.state == UIGestureRecognizerStateEnded) {
+    [self handleLinkGesture:recognizer block:self.onLinkTap];
+  }
+}
+
+- (void)handleLongPress:(UILongPressGestureRecognizer *)recognizer
+{
+  if (recognizer.state == UIGestureRecognizerStateBegan) {
+    [self handleLinkGesture:recognizer block:self.onLinkLongTap];
+  }
+}
+
+@end
+
+#endif // !TARGET_OS_OSX