From 8163beab59d634dd74bf02f5ca12af384339498f Mon Sep 17 00:00:00 2001
From: Yucheng Jin <jyc1219@outlook.com>
Date: Wed, 5 Mar 2025 09:27:21 -0800
Subject: [PATCH] fix: eliminate scroll jitter in iOS text input when editing
 in upper region

---
 ios/PasteTextInput.mm | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/ios/PasteTextInput.mm b/ios/PasteTextInput.mm
index dd50053..bac9d1e 100644
--- a/ios/PasteTextInput.mm
+++ b/ios/PasteTextInput.mm
@@ -597,9 +597,18 @@ - (void)_setAttributedString:(NSAttributedString *)attributedString
   if ([self _textOf:attributedString equals:_backedTextInputView.attributedText]) {
     return;
   }
+  
+  // Save current scroll position
+  CGPoint originalOffset = _backedTextInputView.contentOffset;
+  
+  // Temporarily disable scrolling animations
+  BOOL originalScrollEnabled = _backedTextInputView.scrollEnabled;
+  _backedTextInputView.scrollEnabled = NO;
+  
   UITextRange *selectedRange = _backedTextInputView.selectedTextRange;
   NSInteger oldTextLength = _backedTextInputView.attributedText.string.length;
   _backedTextInputView.attributedText = attributedString;
+  
   if (selectedRange.empty) {
     // Maintaining a cursor position relative to the end of the old text.
     NSInteger offsetStart = [_backedTextInputView offsetFromPosition:_backedTextInputView.beginningOfDocument
@@ -612,6 +621,13 @@ - (void)_setAttributedString:(NSAttributedString *)attributedString
                                 notifyDelegate:YES];
   }
   [self _restoreTextSelection];
+  
+  // Restore scroll position immediately
+  [_backedTextInputView setContentOffset:originalOffset animated:NO];
+  
+  // Re-enable scrolling with original state
+  _backedTextInputView.scrollEnabled = originalScrollEnabled;
+  
   _lastStringStateWasUpdatedWith = attributedString;
 }