From 5ca5e3b6001f7bfcfbc09a441c1956ed17584c41 Mon Sep 17 00:00:00 2001
From: Fabrizio Bertoglio <fabrizio.bertoglio@gmail.com>
Date: Fri, 2 Feb 2024 09:19:28 -0800
Subject: [PATCH] Fix TextInput vertical alignment issue when using lineHeight
 prop on iOS without changing Text baseline (Paper - old arch) (#38359)

Summary:
This PR fixes visual regression introduced with https://github.com/facebook/react-native/pull/37465#issuecomment-1631974927

Adding paragraphStyle.maximumLineHeight to a iOS UITextField displays the text under the UITextField ([ios-screenshot-1][1], [ios-screenshot-2][2], [ios-screenshot-3][3]).

The PR implements the logic from RCTTextShadowView [#postprocessAttributedText](https://github.com/facebook/react-native/blob/9ab27e8895d6934e72ebdc601d169578ab9628f1/packages/react-native/Libraries/Text/Text/RCTTextShadowView.m#L165-L167) in RCTBaseTextInpuShadowView [#uiManagerWillPerformMounting](https://github.com/facebook/react-native/blob/4c944540f732c6055d447ecaf37d5c8f3eec1bc4/packages/react-native/Libraries/Text/TextInput/RCTBaseTextInputShadowView.m#L130-L192).

[1]: https://user-images.githubusercontent.com/24992535/238834159-566f7eef-ea2d-4fd4-a519-099b0a12046c.png "ios-screenshot-1"
[2]: https://user-images.githubusercontent.com/24992535/238834184-feb454a9-6504-4832-aec8-989f1d027861.png "ios-screenshot-2"
[3]: https://user-images.githubusercontent.com/24992535/238834283-cf572f94-a641-4790-92bf-bbe43afb1443.png "ios-screenshot-3"

[4]: https://github.com/Expensify/App/assets/24992535/06726b45-7e35-4003-9fcc-50c8d0dff0f6
[5]: https://github.com/Expensify/App/assets/24992535/d9745d29-8863-4170-bcc3-e78fa7e550d2

fixes https://github.com/facebook/react-native/issues/28012 fixes https://github.com/facebook/react-native/issues/33986
Related https://github.com/facebook/react-native/issues/35741 https://github.com/facebook/react-native/issues/31112

## Changelog:

[IOS] [FIXED] - Fix TextInput vertical alignment issue when using lineHeight prop on iOS without changing Text baseline (Paper - old arch)

Pull Request resolved: https://github.com/facebook/react-native/pull/38359

Test Plan: Extensive test included in the PR comments https://github.com/facebook/react-native/pull/37465#issuecomment-1551459879 and https://github.com/Expensify/App/issues/17767#issuecomment-1640032626

Reviewed By: cipolleschi

Differential Revision: D52325261

Pulled By: dmytrorykun

fbshipit-source-id: d072a598bfaafbbffc41005b1fda1795cf3d8ab9
---
 .../TextInput/RCTBaseTextInputShadowView.mm   | 48 +++++++++++++++++++
 1 file changed, 48 insertions(+)

diff --git a/packages/react-native/Libraries/Text/TextInput/RCTBaseTextInputShadowView.mm b/packages/react-native/Libraries/Text/TextInput/RCTBaseTextInputShadowView.mm
index 1f06b79070aa54..9455bd5734487d 100644
--- a/packages/react-native/Libraries/Text/TextInput/RCTBaseTextInputShadowView.mm
+++ b/packages/react-native/Libraries/Text/TextInput/RCTBaseTextInputShadowView.mm
@@ -158,6 +158,8 @@ - (void)uiManagerWillPerformMounting
     [attributedText insertAttributedString:propertyAttributedText atIndex:0];
   }
 
+  [self postprocessAttributedText:attributedText];
+
   NSAttributedString *newAttributedText;
   if (![_previousAttributedText isEqualToAttributedString:attributedText]) {
     // We have to follow `set prop` pattern:
@@ -191,6 +193,52 @@ - (void)uiManagerWillPerformMounting
   }];
 }
 
+- (void)postprocessAttributedText:(NSMutableAttributedString *)attributedText
+{
+  __block CGFloat maximumLineHeight = 0;
+
+  [attributedText enumerateAttribute:NSParagraphStyleAttributeName
+                             inRange:NSMakeRange(0, attributedText.length)
+                             options:NSAttributedStringEnumerationLongestEffectiveRangeNotRequired
+                          usingBlock:^(NSParagraphStyle *paragraphStyle, __unused NSRange range, __unused BOOL *stop) {
+                            if (!paragraphStyle) {
+                              return;
+                            }
+
+                            maximumLineHeight = MAX(paragraphStyle.maximumLineHeight, maximumLineHeight);
+                          }];
+
+  if (maximumLineHeight == 0) {
+    // `lineHeight` was not specified, nothing to do.
+    return;
+  }
+
+  __block CGFloat maximumFontLineHeight = 0;
+
+  [attributedText enumerateAttribute:NSFontAttributeName
+                             inRange:NSMakeRange(0, attributedText.length)
+                             options:NSAttributedStringEnumerationLongestEffectiveRangeNotRequired
+                          usingBlock:^(UIFont *font, NSRange range, __unused BOOL *stop) {
+                            if (!font) {
+                              return;
+                            }
+
+                            if (maximumFontLineHeight <= font.lineHeight) {
+                              maximumFontLineHeight = font.lineHeight;
+                            }
+                          }];
+
+  if (maximumLineHeight < maximumFontLineHeight) {
+    return;
+  }
+
+  CGFloat baseLineOffset = maximumLineHeight / 2.0 - maximumFontLineHeight / 2.0;
+
+  [attributedText addAttribute:NSBaselineOffsetAttributeName
+                         value:@(baseLineOffset)
+                         range:NSMakeRange(0, attributedText.length)];
+}
+
 #pragma mark -
 
 - (NSAttributedString *)measurableAttributedText