Summary:
Following up on the previous diff to remove the only usage of `listKey` for persistent association, we can remove the need for a manual `listKey`, and instead rely on per-instance association via refs.
A followup change will remove the existing usages.
Changelog:
[General][Removed] - Remove VirtualizedList `listKey` prop
Reviewed By: p-sun
Differential Revision: D39466677
fbshipit-source-id: 6b49f45c987fff9836918ba833fbb16f24414ff8
Summary:
When `getItemLayout` is not supplied, VirtualizedList doesn't know the measurements for its child items ahead of time. It caches most recent cell measurements so that an item which is virtualized away is associated with its correct height. VirtualizedList will not consume space for an item it has not yet rendered/knows measurements for.
This also means an initially created list will only take up the height of its `initialNumToRender()`. This can cause scroll jumping for the scenario of nested VirtualizedLists of the same orientation, since a virtualized away child list will shrink (compared to the spacer), then re-expand, once returned to.
There is logic in the VirtualizedList constructor to load cached frame metrics based on supplied listKey, to enable reloading most recent state. Though locally it seems to be reading the context too early in the lifecycle (compared to other successful checks during componentDidMount, render). It was moved from `componentDidMount` to `constructor` as part of the initial change (https://www.internalfb.com/diff/D6330846 (https://github.com/facebook/react-native/commit/2668dc8e1be7bf93e65ca2e11c87cbeef3310c3e)?dst_version_fbid=131968984136932&transaction_fbid=1578362385612542), and I think has likely been unreliable or dead since.
Restoring state was the only usage of a durable key for nested lists beyond their lifetime. So removing the dead code lets us remove the need for a `listKey`, which has been error-prone. This still leaves the problem present since inception, but there may be alternate solutions like scroll anchoring.
Changelog:
[Internal][Removed] - Remove dead code for restoring state to nested VirtualizedList
Reviewed By: ryancat
Differential Revision: D39466678
fbshipit-source-id: fc2f39802e5cdf9b920974333be64c74211b99a9
Summary:
This change is in preparation of adding a separate `VirtualizedList_EXPERIMENTAL` component.
Both the original, and experimental lists use `VirtualizedListContext`, which itself references back to the VirtualizedList class type. VirtualizedList private methods are currently included in the type system, and are called in other VirtualizedList code (see https://github.com/facebook/react-native/commit/b2f871a6fa9c92dd0712055384b9eca6d828e37d). This prevents Flow from seeing the two classes are compatible if "private" methods change.
My first attempt was to parameterize the context, to allow both `VirtualizedList`, and `VirtualizedList_EXPERIMENTAL` to use the same code without sacrificing type safety or adding further duplication. This added more complexity than it is worth, so I am instead loosening the type on VirtualizedListContext to pass around a more generic handle.
Changelog:
[Internal][Changed] - Allow VirtualizedListContext to support different component type
Reviewed By: javache
Differential Revision: D38017086
fbshipit-source-id: 91e8f6ab2591d3ae9b7f9263711b4a39b78f68e0
Summary:
When a FlatList is nested inside another FlatList, it may be re-rendered whenever the outer FlatList renders. Apply the same optimization we already had in `VirtualizedListContextProvider` to avoid changing the context object if no values have changed.
Changelog: [General][Changed] - Optimized VirtualizedList context when used with nested lists
Reviewed By: genkikondo
Differential Revision: D35905952
fbshipit-source-id: 695253c85db2043d22e208ad94ecc7daa1455055
Summary:
ES Modules implicitly enable strict mode. Adding the "use strict" directive is, therefore, not required.
This diff removes all "use strict" directives from ES modules.
Changelog:
[Internal]
Reviewed By: motiz88
Differential Revision: D26172715
fbshipit-source-id: 57957bcbb672c4c3e62b1db633cf425c1c9d6430
Summary:
Changelog:
[General] [Changed] - Added (DEV-only) `displayName` to some RN contexts to make them more easy to differentiate when debugging.
Reviewed By: lunaleaps
Differential Revision: D24993068
fbshipit-source-id: 4904259eda50444c2f74700a3540ff4fd02ac322