Summary:
Original commit changeset: c45409a8413e
I was unable to find the cause of the problem.
Reviewed By: yungsters
Differential Revision: D16240754
fbshipit-source-id: c1e3f0aa615422f1156706f919e8f851f82c18b0
Summary:
The current technique we use to draw text uses linear memory, which means that when text is too long the UIView layer is unable to draw it. This causes the issue described [here](https://github.com/facebook/react-native/issues/19453). On an iOS simulator the bug happens at around 500 lines which is quite annoying. It can also happen on a real device but requires a lot more text.
To be more specific the amount of text doesn't actually matter, it is the size of the UIView that we use to draw the text. When we use `[drawRect:]` the view creates a bitmap to send to the gpu to render, if that bitmap is too big it cannot render.
To fix this we can use `CATiledLayer` which will split drawing into smaller parts, that gets executed when the content is about to be visible. This drawing is also async which means the text can seem to appear during scroll. See https://developer.apple.com/documentation/quartzcore/calayer?language=objc.
`CATiledLayer` also adds some overhead that we don't want when rendering small amount of text. To fix this we can use either a regular `CALayer` or a `CATiledLayer` depending on the size of the view containing the text. I picked 1024 as the threshold which is about 1 screen and a half, and is still smaller than the height needed for the bug to occur when using a regular `CALayer` on a iOS simulator.
Also found this which addresses the problem in a similar manner and took some inspiration from the code linked there https://github.com/GitHawkApp/StyledTextKit/issues/14#issuecomment-395234885
Fixes https://github.com/facebook/react-native/issues/19453
## Changelog
[iOS] [Fixed] - Use CALayers to draw text, fixes rendering for long text
Pull Request resolved: https://github.com/facebook/react-native/pull/24387
Test Plan:
- Added the example I was using to verify the fix to RNTester.
- Made sure all other examples are still rendering properly.
- Tested text selection
Reviewed By: shergin
Differential Revision: D15918277
Pulled By: sammy-SC
fbshipit-source-id: c45409a8413e6e3ad272be39ba527a4e8d349e28
Summary:
Fix#23849. When setting a semi-transparent background on text, it becomes obvious that we are drawing the background color twice. Since background color is handled by the view, we should not need to draw the glyph background color too.
| Before | After |
| ------------- |-------------|
|<img src="https://i.imgur.com/8JGpKTC.png" width="300"> | <img src="https://imgur.com/qjKU9Ze.png" width="300">
[iOS] [Fixed] - Semi-transparent backgrounds on text
Pull Request resolved: https://github.com/facebook/react-native/pull/23872
Differential Revision: D14430501
Pulled By: shergin
fbshipit-source-id: 19743415b2d20a3b941b1c80bd7b47144e929458
Summary:
Fixes#23459. It is not legal to write the character array of a std::string, and can result in undefined behavior.
[General] [Fixed] - Crash when substring intersects with emoji
Pull Request resolved: https://github.com/facebook/react-native/pull/23609
Differential Revision: D14198159
Pulled By: mdvacca
fbshipit-source-id: 71060b1b99ddab89793c98c09f99ec9974479e62
Summary:
Currently, if we has `defaultValue`, textAttributes like `letterSpacing` can works, but if textinput has not default text, when we typing the text, some attributes not applied.
[iOS] [Fixed] - Fix textAttributes not applied when typing text
Pull Request resolved: https://github.com/facebook/react-native/pull/23585
Differential Revision: D14206568
Pulled By: cpojer
fbshipit-source-id: 7db276d811684bf6e01f8d30287cca80095db87c
Mike Grabowski
Samuel Susla
Janic Duplessis
ericlewis
zhongwuzw
Héctor Ramos
Woraphot Chokratanasombat
