Summary: Not sure how I missed this in 3ce31c24da
Reviewed By: yungsters
Differential Revision: D4731083
fbshipit-source-id: 860ed9d2f99312cd02b84ba467ba66afc5cdd5c5
Summary:
It was just adding unnecessary complexity. Users should just use standard React perf best practices, like `PureComponent` and `shouldComponentUpdate`.
This should be backwards compatible - existing `shouldItemUpdate` usage will just be ignored and should consider migrating to this pattern:
```
class MyItem extends React.PureComponent {
_onPress = () => {
this.props.onPressItem(this.props.id);
};
render() {
return (
<SomeOtherWidget title={this.props.title} onPress={this._onPress} />
)
}
}
...
_renderItem = ({item}) => (
<MyItem onPressItem={this._onPressItem} title={item.title} id={item.id} />
);
```
Which will automatically prevent re-renders unless the relavent data changes.
Reviewed By: yungsters
Differential Revision: D4730599
fbshipit-source-id: 0f61efe96eb4d95bb3b7c4ec889e3e0e34436e56
Summary:
This adds support for both automagical sticky section headers in
`SectionList` as well as the more free-form `stickyHeaderIndices` on
`FlatList` or `VirtualizedList`.
The basic concept is to take the initial `stickySectionHeaders` and remap them
to the indices corresponding to the mounted subset in the render window. The
main trick here is that the currently stuck header might itself be outside of
the render window, so we need to search the gap to see if that's the case and
render it (with spacers above and below it instead of one big spacer).
In the `SectionList` we simply pre-compute the sticky headers at the same time
as when we scan the sections to determine the flattened length and pass those
to `VirtualizedList`.
This also requires some updates to `ScrollView` to work in the churny
environment of `VirtualizedList`. We propogate the keys on the children to the
animated wrappers so that as items are removed and the indices of the
remaining items change, react can keep proper track of them. We also fix the
scroll back case where new headers are rendered from the top down and aren't
updated with the `setNextLayoutY` callback because the `onLayout` call for the
next header happened before it was mounted. This is done by just tracking all
the layout values in a map and providing them to the sticky components at
render time. This might also improve perf a little by property configuring the
animations syncronously instead of waiting for the `onLayout` callback. We
also need to protect against stale onLayout callbacks and other fun stuff.
== Test Plan ==
https://www.facebook.com/groups/react.native.community/permalink/940332509435661/
Scroll a lot with and without debug mode on. Make sure spinner
still spins and there are no crashes (lots of crashes during development due
to the animated configuration being non-monotonic if anything stale values get
through). Also made sure that tapping a row to change it's height would
properly update the animation configurations so the collision point would
still be correct.
Reviewed By: yungsters
Differential Revision: D4695065
fbshipit-source-id: 855c4e31c8f8b450d32150dbdb2e07f1a9f9f98e
Summary: People might be tempted to try and scrollTo an index that hasn't been rendered yet, which is broken, so instead of jank let's throw.
Reviewed By: yungsters
Differential Revision: D4727402
fbshipit-source-id: b6f9fd5b70b6f076c30141d00b2b9e2a51b14e87
Summary:
Thanks for submitting a PR! Please read these instructions carefully:
- [x] Explain the **motivation** for making this change.
- [x] Provide a **test plan** demonstrating that the code is solid.
- [x] Match the **code formatting** of the rest of the codebase.
- [x] Target the `master` branch, NOT a "stable" branch.
There was a typo in the FlatList docs for numColumns affecting the formatting of its description.
N/A
Sign the [CLA][2], if you haven't already.
Small pull requests are much easier to review and more likely to get merged. Make sure the PR does only one thing, otherwise please split it.
Make sure all **tests pass** on both [Travis][3] and [Circle CI][4]. PRs that break tests are unlikely to be merged.
For more info, see the ["Pull Requests"][5] section of our "Contributing" guidelines.
[1]: https://medium.com/martinkonicek/what-is-a-test-plan-8bfc840ec171#.y9lcuqqi9
[2]: https://code.facebook.com/cla
Closes https://github.com/facebook/react-native/pull/13002
Differential Revision: D4735343
fbshipit-source-id: f781c50c892d64e69f61aec980614e948a48f48b
Summary: Forgot to update these after rename...
Reviewed By: yungsters
Differential Revision: D4723788
fbshipit-source-id: 8cf7e8de57a23d9ee0a424aa9c0d62ab1cfbbb12
Summary:
Only a small amendment, but took me a little bit to figure out why this wasn't working.
Closes https://github.com/facebook/react-native/pull/12706
Differential Revision: D4656700
fbshipit-source-id: d6038581aa70e96a2be775a7a9786e8c7e64f762
Summary: I think these are sufficiently baked. Also beef up comments.
Reviewed By: yungsters
Differential Revision: D4632604
fbshipit-source-id: 64ae6b240a05d62e418099f7403e1781f9b4717c