fix(ios): inline math height calculations

packages/react-native-enriched-markdown/ios/attachments/ENRMMathInlineAttachment.h

@@ -9,6 +9,8 @@ NS_ASSUME_NONNULL_BEGIN
 @property (nonatomic, assign) CGFloat fontSize;
 @property (nonatomic, strong, nullable) RCTUIColor *mathTextColor;
 
+@property (nonatomic, readonly) CGFloat boxHeight;
+
 #if TARGET_OS_OSX
 /// Pre-renders the formula into self.image and sets self.bounds.
 /// Must be called after latex/fontSize/mathTextColor are set, before the

packages/react-native-enriched-markdown/ios/attachments/ENRMMathInlineAttachment.m

@@ -10,6 +10,14 @@
 
 @implementation ENRMMathInlineAttachment
 
+- (CGFloat)boxHeight
+{
+#if !TARGET_OS_OSX
+  [self prepareIfNeeded];
+#endif
+  return _cachedSize.height;
+}
+
 #if !TARGET_OS_OSX
 
 - (void)prepareIfNeeded

packages/react-native-enriched-markdown/ios/utils/ParagraphStyleUtils.m

@@ -284,37 +284,68 @@ void applyBaselineOffset(NSMutableAttributedString *output, NSRange range)
     return;
   }
 
-  __block CGFloat maximumLineHeight = 0;
+  // Math paragraphs leave maximumLineHeight at 0, so fall back to minimumLineHeight.
+  __block CGFloat targetLineHeight = 0;
   [output enumerateAttribute:NSParagraphStyleAttributeName
                      inRange:range
                      options:NSAttributedStringEnumerationLongestEffectiveRangeNotRequired
                   usingBlock:^(NSParagraphStyle *paragraphStyle, __unused NSRange subrange, __unused BOOL *stop) {
                     if (!paragraphStyle) {
                       return;
                     }
-                    maximumLineHeight = MAX(paragraphStyle.maximumLineHeight, maximumLineHeight);
+                    CGFloat clamp = MAX(paragraphStyle.maximumLineHeight, paragraphStyle.minimumLineHeight);
+                    targetLineHeight = MAX(clamp, targetLineHeight);
                   }];
 
-  if (maximumLineHeight <= 0) {
+  if (targetLineHeight <= 0) {
     return;
   }
 
-  __block CGFloat maximumFontLineHeight = 0;
-  [output enumerateAttribute:NSFontAttributeName
-                     inRange:range
-                     options:NSAttributedStringEnumerationLongestEffectiveRangeNotRequired
-                  usingBlock:^(UIFont *font, __unused NSRange subrange, __unused BOOL *stop) {
-                    if (!font) {
-                      return;
-                    }
-                    maximumFontLineHeight = MAX(UIFontLineHeight(font), maximumFontLineHeight);
-                  }];
+  // Center on real text; on a math-only line center the math box instead of its font.
+  __block CGFloat textLineHeight = 0;
+#if ENRICHED_MARKDOWN_MATH
+  __block BOOL hasMath = NO;
+#endif
+  [output enumerateAttributesInRange:range
+                             options:0
+                          usingBlock:^(NSDictionary<NSAttributedStringKey, id> *attrs, __unused NSRange subrange,
+                                       __unused BOOL *stop) {
+#if ENRICHED_MARKDOWN_MATH
+                            if ([attrs[NSAttachmentAttributeName] isKindOfClass:[ENRMMathInlineAttachment class]]) {
+                              hasMath = YES;
+                              return;
+                            }
+#endif
+                            UIFont *font = attrs[NSFontAttributeName];
+                            if (font) {
+                              textLineHeight = MAX(UIFontLineHeight(font), textLineHeight);
+                            }
+                          }];
+
+  CGFloat contentLineHeight = textLineHeight;
+
+#if ENRICHED_MARKDOWN_MATH
+  // Math only grows the content height, so measure it (parsing LaTeX) only when text
+  // alone wouldn't already fill the line.
+  if (hasMath && targetLineHeight > textLineHeight) {
+    __block CGFloat mathBoxHeight = 0;
+    [output enumerateAttribute:NSAttachmentAttributeName
+                       inRange:range
+                       options:0
+                    usingBlock:^(id value, __unused NSRange subrange, __unused BOOL *stop) {
+                      if ([value isKindOfClass:[ENRMMathInlineAttachment class]]) {
+                        mathBoxHeight = MAX(((ENRMMathInlineAttachment *)value).boxHeight, mathBoxHeight);
+                      }
+                    }];
+    contentLineHeight = MAX(textLineHeight, mathBoxHeight);
+  }
+#endif
 
-  if (maximumFontLineHeight <= 0 || maximumLineHeight < maximumFontLineHeight) {
+  if (contentLineHeight <= 0 || targetLineHeight <= contentLineHeight) {
     return;
   }
 
-  CGFloat baseLineOffset = (maximumLineHeight - maximumFontLineHeight) / 2.0;
+  CGFloat baseLineOffset = (targetLineHeight - contentLineHeight) / 2.0;
 
   [output enumerateAttribute:NSBaselineOffsetAttributeName
                      inRange:range