GT2/Ejectable/node_modules/react-native/Libraries/Lists/SectionList.js

265 lines
8.8 KiB
JavaScript

/**
* Copyright (c) Facebook, Inc. and its affiliates.
*
* This source code is licensed under the MIT license found in the
* LICENSE file in the root directory of this source tree.
*
* @flow
* @format
*/
'use strict';
const Platform = require('../Utilities/Platform');
const React = require('react');
const VirtualizedSectionList = require('./VirtualizedSectionList');
import type {ScrollResponderType} from '../Components/ScrollView/ScrollView';
import type {
SectionBase as _SectionBase,
Props as VirtualizedSectionListProps,
ScrollToLocationParamsType,
} from './VirtualizedSectionList';
type Item = any;
export type SectionBase<SectionItemT> = _SectionBase<SectionItemT>;
type RequiredProps<SectionT: SectionBase<any>> = {|
/**
* The actual data to render, akin to the `data` prop in [`<FlatList>`](https://reactnative.dev/docs/flatlist.html).
*
* General shape:
*
* sections: $ReadOnlyArray<{
* data: $ReadOnlyArray<SectionItem>,
* renderItem?: ({item: SectionItem, ...}) => ?React.Element<*>,
* ItemSeparatorComponent?: ?ReactClass<{highlighted: boolean, ...}>,
* }>
*/
sections: $ReadOnlyArray<SectionT>,
|};
type OptionalProps<SectionT: SectionBase<any>> = {|
/**
* Default renderer for every item in every section. Can be over-ridden on a per-section basis.
*/
renderItem?: (info: {
item: Item,
index: number,
section: SectionT,
separators: {
highlight: () => void,
unhighlight: () => void,
updateProps: (select: 'leading' | 'trailing', newProps: Object) => void,
...
},
...
}) => null | React.Element<any>,
/**
* A marker property for telling the list to re-render (since it implements `PureComponent`). If
* any of your `renderItem`, Header, Footer, etc. functions depend on anything outside of the
* `data` prop, stick it here and treat it immutably.
*/
extraData?: any,
/**
* How many items to render in the initial batch. This should be enough to fill the screen but not
* much more. Note these items will never be unmounted as part of the windowed rendering in order
* to improve perceived performance of scroll-to-top actions.
*/
initialNumToRender: number,
/**
* Reverses the direction of scroll. Uses scale transforms of -1.
*/
inverted?: ?boolean,
/**
* Used to extract a unique key for a given item at the specified index. Key is used for caching
* and as the react key to track item re-ordering. The default extractor checks item.key, then
* falls back to using the index, like react does. Note that this sets keys for each item, but
* each overall section still needs its own key.
*/
keyExtractor: (item: Item, index: number) => string,
/**
* Called once when the scroll position gets within `onEndReachedThreshold` of the rendered
* content.
*/
onEndReached?: ?(info: {distanceFromEnd: number, ...}) => void,
/**
* Note: may have bugs (missing content) in some circumstances - use at your own risk.
*
* This may improve scroll performance for large lists.
*/
removeClippedSubviews?: boolean,
|};
export type Props<SectionT> = {|
...$Diff<
VirtualizedSectionListProps<SectionT>,
{
getItem: $PropertyType<VirtualizedSectionListProps<SectionT>, 'getItem'>,
getItemCount: $PropertyType<
VirtualizedSectionListProps<SectionT>,
'getItemCount',
>,
renderItem: $PropertyType<
VirtualizedSectionListProps<SectionT>,
'renderItem',
>,
...
},
>,
...RequiredProps<SectionT>,
...OptionalProps<SectionT>,
|};
const defaultProps = {
...VirtualizedSectionList.defaultProps,
stickySectionHeadersEnabled: Platform.OS === 'ios',
};
type DefaultProps = typeof defaultProps;
/**
* A performant interface for rendering sectioned lists, supporting the most handy features:
*
* - Fully cross-platform.
* - Configurable viewability callbacks.
* - List header support.
* - List footer support.
* - Item separator support.
* - Section header support.
* - Section separator support.
* - Heterogeneous data and item rendering support.
* - Pull to Refresh.
* - Scroll loading.
*
* If you don't need section support and want a simpler interface, use
* [`<FlatList>`](https://reactnative.dev/docs/flatlist.html).
*
* Simple Examples:
*
* <SectionList
* renderItem={({item}) => <ListItem title={item} />}
* renderSectionHeader={({section}) => <Header title={section.title} />}
* sections={[ // homogeneous rendering between sections
* {data: [...], title: ...},
* {data: [...], title: ...},
* {data: [...], title: ...},
* ]}
* />
*
* <SectionList
* sections={[ // heterogeneous rendering between sections
* {data: [...], renderItem: ...},
* {data: [...], renderItem: ...},
* {data: [...], renderItem: ...},
* ]}
* />
*
* This is a convenience wrapper around [`<VirtualizedList>`](docs/virtualizedlist.html),
* and thus inherits its props (as well as those of `ScrollView`) that aren't explicitly listed
* here, along with the following caveats:
*
* - Internal state is not preserved when content scrolls out of the render window. Make sure all
* your data is captured in the item data or external stores like Flux, Redux, or Relay.
* - This is a `PureComponent` which means that it will not re-render if `props` remain shallow-
* equal. Make sure that everything your `renderItem` function depends on is passed as a prop
* (e.g. `extraData`) that is not `===` after updates, otherwise your UI may not update on
* changes. This includes the `data` prop and parent component state.
* - In order to constrain memory and enable smooth scrolling, content is rendered asynchronously
* offscreen. This means it's possible to scroll faster than the fill rate and momentarily see
* blank content. This is a tradeoff that can be adjusted to suit the needs of each application,
* and we are working on improving it behind the scenes.
* - By default, the list looks for a `key` prop on each item and uses that for the React key.
* Alternatively, you can provide a custom `keyExtractor` prop.
*
*/
class SectionList<SectionT: SectionBase<any>> extends React.PureComponent<
Props<SectionT>,
void,
> {
props: Props<SectionT>;
static defaultProps: DefaultProps = defaultProps;
/**
* Scrolls to the item at the specified `sectionIndex` and `itemIndex` (within the section)
* positioned in the viewable area such that `viewPosition` 0 places it at the top (and may be
* covered by a sticky header), 1 at the bottom, and 0.5 centered in the middle. `viewOffset` is a
* fixed number of pixels to offset the final target position, e.g. to compensate for sticky
* headers.
*
* Note: cannot scroll to locations outside the render window without specifying the
* `getItemLayout` prop.
*/
scrollToLocation(params: ScrollToLocationParamsType) {
if (this._wrapperListRef != null) {
this._wrapperListRef.scrollToLocation(params);
}
}
/**
* Tells the list an interaction has occurred, which should trigger viewability calculations, e.g.
* if `waitForInteractions` is true and the user has not scrolled. This is typically called by
* taps on items or by navigation actions.
*/
recordInteraction() {
const listRef = this._wrapperListRef && this._wrapperListRef.getListRef();
listRef && listRef.recordInteraction();
}
/**
* Displays the scroll indicators momentarily.
*
* @platform ios
*/
flashScrollIndicators() {
const listRef = this._wrapperListRef && this._wrapperListRef.getListRef();
listRef && listRef.flashScrollIndicators();
}
/**
* Provides a handle to the underlying scroll responder.
*/
getScrollResponder(): ?ScrollResponderType {
const listRef = this._wrapperListRef && this._wrapperListRef.getListRef();
if (listRef) {
return listRef.getScrollResponder();
}
}
getScrollableNode(): any {
const listRef = this._wrapperListRef && this._wrapperListRef.getListRef();
if (listRef) {
return listRef.getScrollableNode();
}
}
setNativeProps(props: Object) {
const listRef = this._wrapperListRef && this._wrapperListRef.getListRef();
if (listRef) {
listRef.setNativeProps(props);
}
}
render(): React.Node {
return (
<VirtualizedSectionList
{...this.props}
ref={this._captureRef}
getItemCount={items => items.length}
getItem={(items, index) => items[index]}
/>
);
}
_wrapperListRef: ?React.ElementRef<typeof VirtualizedSectionList>;
_captureRef = ref => {
/* $FlowFixMe(>=0.99.0 site=react_native_fb) This comment suppresses an
* error found when Flow v0.99 was deployed. To see the error, delete this
* comment and run Flow. */
this._wrapperListRef = ref;
};
}
module.exports = SectionList;