Add RTL/bidi support for Hebrew and Arabic content (web + mobile)

apps/mobile/modules/t3-composer-editor/ios/T3ComposerEditorModule.swift

@@ -69,6 +69,9 @@ public class T3ComposerEditorModule: Module {
       Prop("contentInsetVertical") { (view: T3ComposerEditorView, contentInsetVertical: Double) in
         view.setContentInsetVertical(CGFloat(contentInsetVertical))
       }
+      Prop("writingDirection") { (view: T3ComposerEditorView, writingDirection: String) in
+        view.setWritingDirection(writingDirection)
+      }
       Prop("editable") { (view: T3ComposerEditorView, editable: Bool) in
         view.setEditable(editable)
       }

apps/mobile/modules/t3-composer-editor/ios/T3ComposerEditorView.swift

@@ -427,6 +427,7 @@ public final class T3ComposerEditorView: ExpoView, UITextViewDelegate, UITextDro
   private var fontSize: CGFloat = 14
   private var lineHeight: CGFloat = 20
   private var contentInsetVertical: CGFloat = 0
+  private var isRightToLeft = false
   private var shouldAutoFocus = false
   private var didAutoFocus = false
   private var isReadOnly = false
@@ -667,6 +668,31 @@ public final class T3ComposerEditorView: ExpoView, UITextViewDelegate, UITextDro
     setNeedsLayout()
   }
 
+  // Live composer direction, decided in JS from the draft's first strong
+  // letter. UIKit does not re-resolve a text view's base direction from its
+  // content, and restoreBaseTypingAttributes would clobber any keyboard-driven
+  // direction anyway — so the direction rides the base paragraph style, which
+  // TextKit's natural alignment follows, and the existing text is restyled in
+  // place (never rebuilt: a rebuild from the controlled value could race a
+  // keystroke the revision guard has not acknowledged yet).
+  func setWritingDirection(_ writingDirection: String) {
+    let isRTL = writingDirection == "rtl"
+    guard isRTL != isRightToLeft else {
+      return
+    }
+    isRightToLeft = isRTL
+    placeholderLabel.textAlignment = isRTL ? .right : .left
+    let storageRange = NSRange(location: 0, length: textView.textStorage.length)
+    if storageRange.length > 0 {
+      textView.textStorage.addAttribute(
+        .paragraphStyle,
+        value: baseParagraphStyle(),
+        range: storageRange
+      )
+    }
+    restoreBaseTypingAttributes()
+  }
+
   func setEditable(_ editable: Bool) {
     textView.isEditable = editable
   }
@@ -1055,16 +1081,22 @@ public final class T3ComposerEditorView: ExpoView, UITextViewDelegate, UITextDro
     return nil
   }
 
-  private func baseAttributes() -> [NSAttributedString.Key: Any] {
-    let font = UIFont(name: fontFamily, size: fontSize)
-      ?? UIFont.systemFont(ofSize: fontSize)
+  private func baseParagraphStyle() -> NSParagraphStyle {
     let paragraph = NSMutableParagraphStyle()
     paragraph.minimumLineHeight = lineHeight
     paragraph.maximumLineHeight = lineHeight
+    paragraph.baseWritingDirection = isRightToLeft ? .rightToLeft : .leftToRight
+    paragraph.alignment = .natural
+    return paragraph
+  }
+
+  private func baseAttributes() -> [NSAttributedString.Key: Any] {
+    let font = UIFont(name: fontFamily, size: fontSize)
+      ?? UIFont.systemFont(ofSize: fontSize)
     return [
       .font: font,
       .foregroundColor: UIColor(composerHex: theme.text) ?? .label,
-      .paragraphStyle: paragraph,
+      .paragraphStyle: baseParagraphStyle(),
     ]
   }
 

apps/mobile/modules/t3-markdown-text/android/src/main/java/expo/modules/t3markdowntext/T3MarkdownTextSelectionModule.kt

@@ -33,6 +33,10 @@ import java.io.ByteArrayOutputStream
 import kotlin.math.ceil
 
 private const val OBJECT_REPLACEMENT_CHARACTER = "\uFFFC"
+// The markdown renderer wraps inline code in an RTL paragraph with an LTR bidi
+// isolate (LRI \u2066 \u2026 PDI \u2069) so it renders left-to-right without a Text
+// ref call per span. Invisible in the UI, but must not leak into a paste.
+private val BIDI_ISOLATE_CHARACTERS = setOf('\u2066', '\u2069')
 
 // Match React Native's measurement buffer. Android orders tied line-height
 // spans differently in SpannableString, shifting inline images once RN's
@@ -47,7 +51,13 @@ internal fun copyTextWithoutInlineImages(
   start: Int,
   end: Int
 ): String {
-  if (text !is Spanned) return text.subSequence(start, end).toString()
+  if (text !is Spanned) {
+    return buildString {
+      for (index in start until end) {
+        if (text[index] !in BIDI_ISOLATE_CHARACTERS) append(text[index])
+      }
+    }
+  }
 
   fun isInlineImage(index: Int): Boolean =
     index >= 0 && text[index].toString() == OBJECT_REPLACEMENT_CHARACTER &&
@@ -58,7 +68,9 @@ internal fun copyTextWithoutInlineImages(
       // The renderer inserts one NBSP after each image to keep its label on the same line.
       // Inspect the original text even when selection starts after the image.
       val isIconSpacer = text[index] == '\u00A0' && isInlineImage(index - 1)
-      if (!isInlineImage(index) && !isIconSpacer) append(text[index])
+      if (!isInlineImage(index) && !isIconSpacer && text[index] !in BIDI_ISOLATE_CHARACTERS) {
+        append(text[index])
+      }
     }
   }
 }
@@ -81,7 +93,12 @@ private fun canonicalSelection(
       hasContext = true
     }
   }
-  return if (hasContext) canonical.toString().replace(OBJECT_REPLACEMENT_CHARACTER, "") else null
+  if (!hasContext) return null
+  var sanitized = canonical.toString().replace(OBJECT_REPLACEMENT_CHARACTER, "")
+  for (isolate in BIDI_ISOLATE_CHARACTERS) {
+    sanitized = sanitized.replace(isolate.toString(), "")
+  }
+  return sanitized
 }
 
 private fun selectedContextRecords(records: JSONArray, selectedText: String): JSONArray {

apps/mobile/modules/t3-markdown-text/ios/T3MarkdownText.mm

@@ -27,7 +27,13 @@ - (BOOL)accessibilityActivate
 }
 @end
 
-/** Preserve canonical references and their payload when copying a native text selection. */
+/**
+ * Preserve canonical references and their payload when copying a native text
+ * selection. Also strips characters the markdown renderer embeds but that
+ * must never leak into a paste: the object-replacement character used for
+ * file/skill icon placeholders, and the LTR bidi isolate (LRI \u2066 / PDI
+ * \u2069) inline code gets wrapped in inside RTL paragraphs.
+ */
 @interface T3ContextCopyTextView : UITextView
 @property(nonatomic, copy) NSDictionary *contextClipboardConfig;
 @end
@@ -45,12 +51,14 @@ - (BOOL)canPerformAction:(SEL)action withSender:(id)sender
 - (void)copy:(id)sender
 {
   NSRange selected = self.selectedRange;
-  NSArray *ranges = self.contextClipboardConfig[@"ranges"];
-  if (selected.location == NSNotFound || selected.length == 0 || NSMaxRange(selected) > self.text.length || ranges.count == 0) {
+  if (selected.location == NSNotFound || selected.length == 0 || NSMaxRange(selected) > self.text.length) {
     [super copy:sender];
     return;
   }
-  NSMutableString *text = [[self.text substringWithRange:selected] mutableCopy];
+
+  NSString *originalText = [self.text substringWithRange:selected];
+  NSArray *ranges = self.contextClipboardConfig[@"ranges"];
+  NSMutableString *text = [originalText mutableCopy];
   BOOL hasContext = NO;
   for (NSDictionary *range in [ranges reverseObjectEnumerator]) {
     NSUInteger start = [range[@"start"] unsignedIntegerValue];
@@ -61,8 +69,20 @@ - (void)copy:(id)sender
     [text replaceCharactersInRange:NSMakeRange(overlap.location - selected.location, overlap.length) withString:range[@"text"]];
     hasContext = YES;
   }
-  if (!hasContext) { [super copy:sender]; return; }
+
   [text replaceOccurrencesOfString:@"\uFFFC\u00A0" withString:@"" options:0 range:NSMakeRange(0, text.length)];
+  [text replaceOccurrencesOfString:@"\uFFFC" withString:@"" options:0 range:NSMakeRange(0, text.length)];
+  [text replaceOccurrencesOfString:@"\u2066" withString:@"" options:0 range:NSMakeRange(0, text.length)];
+  [text replaceOccurrencesOfString:@"\u2069" withString:@"" options:0 range:NSMakeRange(0, text.length)];
+
+  if (!hasContext) {
+    if ([text isEqualToString:originalText]) {
+      [super copy:sender];
+    } else {
+      UIPasteboard.generalPasteboard.string = text;
+    }
+    return;
+  }
   NSString *fragment = self.contextClipboardConfig[@"fragment"];
   NSMutableDictionary *payload = [[NSJSONSerialization JSONObjectWithData:[fragment dataUsingEncoding:NSUTF8StringEncoding] options:NSJSONReadingMutableContainers error:nil] mutableCopy];
   NSArray *records = payload[@"records"];
@@ -113,8 +133,13 @@ static void T3MarkdownTextApplyParagraphStyles(
     paragraphStyle.firstLineHeadIndent = styleRange.firstLineHeadIndent;
     paragraphStyle.headIndent = styleRange.headIndent;
     paragraphStyle.paragraphSpacing = styleRange.paragraphSpacing;
+    if (styleRange.rtl) {
+      paragraphStyle.baseWritingDirection = NSWritingDirectionRightToLeft;
+    }
+    // Must match applyParagraphStyles in T3MarkdownTextShadowNode.mm (measure path).
     paragraphStyle.tabStops = @[
-      [[NSTextTab alloc] initWithTextAlignment:NSTextAlignmentLeft
+      [[NSTextTab alloc] initWithTextAlignment:styleRange.rtl ? NSTextAlignmentRight
+                                              : NSTextAlignmentLeft
                                       location:styleRange.headIndent
                                        options:@{}]
     ];

apps/mobile/modules/t3-markdown-text/ios/T3MarkdownTextShadowNode.h

@@ -20,6 +20,10 @@ struct T3MarkdownTextParagraphStyleRange {
   Float firstLineHeadIndent;
   Float headIndent;
   Float paragraphSpacing;
+  // RTL paragraphs (Hebrew/Arabic list items) need their base writing direction
+  // pinned and their marker tab stop right-aligned; TextKit flips the head
+  // indents to the leading (right) edge on its own.
+  bool rtl;
 };
 
 struct T3MarkdownTextAttachmentRange {

apps/mobile/modules/t3-markdown-text/ios/T3MarkdownTextShadowNode.mm

@@ -36,8 +36,14 @@ static void applyParagraphStyles(
     paragraphStyle.firstLineHeadIndent = styleRange.firstLineHeadIndent;
     paragraphStyle.headIndent = styleRange.headIndent;
     paragraphStyle.paragraphSpacing = styleRange.paragraphSpacing;
+    if (styleRange.rtl) {
+      paragraphStyle.baseWritingDirection = NSWritingDirectionRightToLeft;
+    }
+    // The tab stop's alignment matches the paragraph's writing direction so the
+    // list-marker column sits on the leading edge (right, for RTL paragraphs).
     paragraphStyle.tabStops = @[
-      [[NSTextTab alloc] initWithTextAlignment:NSTextAlignmentLeft
+      [[NSTextTab alloc] initWithTextAlignment:styleRange.rtl ? NSTextAlignmentRight
+                                              : NSTextAlignmentLeft
                                       location:styleRange.headIndent
                                        options:@{}]
     ];
@@ -179,6 +185,15 @@ static void applyAttachments(
           textAttributes.alignment = TextAlignment::Natural;
         }
 
+        // Natural alignment follows the paragraph's base writing direction, so an
+        // explicit "rtl" run right-aligns and reorders as Hebrew/Arabic prose while
+        // "ltr" pins code, and "auto" keeps TextKit's first-strong resolution.
+        if (props.writingDirection == T3MarkdownTextRunWritingDirection::Ltr) {
+          textAttributes.baseWritingDirection = WritingDirection::LeftToRight;
+        } else if (props.writingDirection == T3MarkdownTextRunWritingDirection::Rtl) {
+          textAttributes.baseWritingDirection = WritingDirection::RightToLeft;
+        }
+
         textAttributes.backgroundColor = props.backgroundColor;
 
         fragment.string = props.text;
@@ -193,6 +208,7 @@ static void applyAttachments(
               props.shadowOffset.width,
               props.shadowOffset.height,
               props.shadowRadius - ParagraphStyleEncodingOffset,
+              props.writingDirection == T3MarkdownTextRunWritingDirection::Rtl,
           });
         }
         if (props.nativeId.rfind("t3-chip:", 0) == 0 && fragmentLength > 0) {