Fix calling onScroll multiple times with incorrect y-axis offset

[tomekzaw]

Details

Fixes #139. Fixes #136.

This PR fixes the incorrect behavior of MarkdownTextInput when maxHeight is set, in particular:

1. eliminates emitting onLayout events on each keypress with incorrect y-axis offset
2. restores automatically scrolling to the next line once newline character is appended

Source: https://stackoverflow.com/a/43270032/23325954

Related Issues

GH_LINK

Manual Tests

Linked PRs

[robertKozik]

Also fixes #136

proof on example app

Screen.Recording.2024-01-31.at.15.55.49.mov

[tomekzaw]

Repro for #136 and #139 on 2fa000c (using TextKit 1):

<MarkdownTextInput
  multiline
  autoCapitalize="none"
  value={value}
  onChangeText={setValue}
  style={[styles.input, {maxHeight: 120}]}
  onScroll={(e) => console.log(e.nativeEvent.contentOffset)}
  ref={ref}
/>

❌ Incorrect onLayout events are emitted on each keypress	❌ Content is not scrolled automatically when appending a newline	✅ Content offset stays correct on each keypress
Screen.Recording.2024-01-31.at.18.59.15.mov	Screen.Recording.2024-01-31.at.18.56.45.mov	Screen.Recording.2024-01-31.at.19.14.32.mov

After commenting out _textView.layoutManager (effectively using TextKit 2 instead of TextKit 1):

✅ Correct onLayout events are emitted only when needed	✅ Content is scrolled automatically when appending a newline	❌ Content offset alternates on each keypress
Screen.Recording.2024-01-31.at.19.06.11.mov	Screen.Recording.2024-01-31.at.19.06.33.mov	Screen.Recording.2024-01-31.at.19.12.47.mov

After restoring _textView.layoutManager and adding layoutManager.allowsNonContiguousLayout = NO;:

✅ Correct onLayout events are emitted only when needed	✅ Content is scrolled automatically when appending a newline	✅ Content offset stays correct on each keypress
Screen.Recording.2024-01-31.at.19.19.58.mov	Screen.Recording.2024-01-31.at.19.22.41.mov	Screen.Recording.2024-01-31.at.19.19.28.mov

[robertKozik]

🎉 🎉 🎉