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122dc37afe
Summary: Currently, modifying a component that renders a FlatLists while Hot Reloading is enabled will trigger an invariant inside FlatList for changing viewabilityConfig on the fly. This happens because it checks object equality between the configs. By checking equality of the config's *properties* instead, we maintain the efficacy of the invariant but keep it from falsely triggering during development. Reviewed By: sahrens Differential Revision: D9466129 fbshipit-source-id: 67149e9e70ad7b2e2584bb7ec03e2dea26ef45e8
682 lines
23 KiB
JavaScript
682 lines
23 KiB
JavaScript
/**
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* Copyright (c) 2015-present, Facebook, Inc.
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*
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* This source code is licensed under the MIT license found in the
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* LICENSE file in the root directory of this source tree.
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*
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* @flow
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* @format
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*/
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'use strict';
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const deepDiffer = require('deepDiffer');
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const MetroListView = require('MetroListView'); // Used as a fallback legacy option
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const React = require('React');
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const View = require('View');
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const VirtualizedList = require('VirtualizedList');
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const ListView = require('ListView');
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const StyleSheet = require('StyleSheet');
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const invariant = require('fbjs/lib/invariant');
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import type {ViewStyleProp} from 'StyleSheet';
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import type {
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ViewabilityConfig,
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ViewToken,
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ViewabilityConfigCallbackPair,
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} from 'ViewabilityHelper';
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import type {Props as VirtualizedListProps} from 'VirtualizedList';
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export type SeparatorsObj = {
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highlight: () => void,
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unhighlight: () => void,
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updateProps: (select: 'leading' | 'trailing', newProps: Object) => void,
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};
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type RequiredProps<ItemT> = {
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/**
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* Takes an item from `data` and renders it into the list. Example usage:
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*
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* <FlatList
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* ItemSeparatorComponent={Platform.OS !== 'android' && ({highlighted}) => (
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* <View style={[style.separator, highlighted && {marginLeft: 0}]} />
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* )}
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* data={[{title: 'Title Text', key: 'item1'}]}
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* renderItem={({item, separators}) => (
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* <TouchableHighlight
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* onPress={() => this._onPress(item)}
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* onShowUnderlay={separators.highlight}
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* onHideUnderlay={separators.unhighlight}>
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* <View style={{backgroundColor: 'white'}}>
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* <Text>{item.title}</Text>
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* </View>
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* </TouchableHighlight>
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* )}
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* />
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*
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* Provides additional metadata like `index` if you need it, as well as a more generic
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* `separators.updateProps` function which let's you set whatever props you want to change the
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* rendering of either the leading separator or trailing separator in case the more common
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* `highlight` and `unhighlight` (which set the `highlighted: boolean` prop) are insufficient for
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* your use-case.
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*/
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renderItem: (info: {
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item: ItemT,
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index: number,
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separators: SeparatorsObj,
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}) => ?React.Element<any>,
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/**
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* For simplicity, data is just a plain array. If you want to use something else, like an
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* immutable list, use the underlying `VirtualizedList` directly.
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*/
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data: ?$ReadOnlyArray<ItemT>,
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};
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type OptionalProps<ItemT> = {
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/**
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* Rendered in between each item, but not at the top or bottom. By default, `highlighted` and
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* `leadingItem` props are provided. `renderItem` provides `separators.highlight`/`unhighlight`
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* which will update the `highlighted` prop, but you can also add custom props with
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* `separators.updateProps`.
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*/
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ItemSeparatorComponent?: ?React.ComponentType<any>,
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/**
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* Rendered when the list is empty. Can be a React Component Class, a render function, or
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* a rendered element.
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*/
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ListEmptyComponent?: ?(React.ComponentType<any> | React.Element<any>),
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/**
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* Rendered at the bottom of all the items. Can be a React Component Class, a render function, or
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* a rendered element.
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*/
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ListFooterComponent?: ?(React.ComponentType<any> | React.Element<any>),
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/**
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* Styling for internal View for ListFooterComponent
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*/
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ListFooterComponentStyle?: ViewStyleProp,
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/**
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* Rendered at the top of all the items. Can be a React Component Class, a render function, or
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* a rendered element.
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*/
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ListHeaderComponent?: ?(React.ComponentType<any> | React.Element<any>),
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/**
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* Styling for internal View for ListHeaderComponent
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*/
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ListHeaderComponentStyle?: ViewStyleProp,
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/**
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* Optional custom style for multi-item rows generated when numColumns > 1.
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*/
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columnWrapperStyle?: ViewStyleProp,
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/**
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* A marker property for telling the list to re-render (since it implements `PureComponent`). If
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* any of your `renderItem`, Header, Footer, etc. functions depend on anything outside of the
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* `data` prop, stick it here and treat it immutably.
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*/
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extraData?: any,
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/**
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* `getItemLayout` is an optional optimizations that let us skip measurement of dynamic content if
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* you know the height of items a priori. `getItemLayout` is the most efficient, and is easy to
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* use if you have fixed height items, for example:
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*
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* getItemLayout={(data, index) => (
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* {length: ITEM_HEIGHT, offset: ITEM_HEIGHT * index, index}
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* )}
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*
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* Adding `getItemLayout` can be a great performance boost for lists of several hundred items.
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* Remember to include separator length (height or width) in your offset calculation if you
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* specify `ItemSeparatorComponent`.
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*/
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getItemLayout?: (
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data: ?Array<ItemT>,
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index: number,
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) => {length: number, offset: number, index: number},
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/**
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* If true, renders items next to each other horizontally instead of stacked vertically.
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*/
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horizontal?: ?boolean,
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/**
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* How many items to render in the initial batch. This should be enough to fill the screen but not
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* much more. Note these items will never be unmounted as part of the windowed rendering in order
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* to improve perceived performance of scroll-to-top actions.
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*/
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initialNumToRender: number,
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/**
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* Instead of starting at the top with the first item, start at `initialScrollIndex`. This
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* disables the "scroll to top" optimization that keeps the first `initialNumToRender` items
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* always rendered and immediately renders the items starting at this initial index. Requires
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* `getItemLayout` to be implemented.
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*/
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initialScrollIndex?: ?number,
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/**
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* Reverses the direction of scroll. Uses scale transforms of -1.
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*/
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inverted?: ?boolean,
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/**
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* Used to extract a unique key for a given item at the specified index. Key is used for caching
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* and as the react key to track item re-ordering. The default extractor checks `item.key`, then
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* falls back to using the index, like React does.
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*/
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keyExtractor: (item: ItemT, index: number) => string,
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/**
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* Multiple columns can only be rendered with `horizontal={false}` and will zig-zag like a
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* `flexWrap` layout. Items should all be the same height - masonry layouts are not supported.
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*/
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numColumns: number,
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/**
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* Called once when the scroll position gets within `onEndReachedThreshold` of the rendered
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* content.
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*/
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onEndReached?: ?(info: {distanceFromEnd: number}) => void,
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/**
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* How far from the end (in units of visible length of the list) the bottom edge of the
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* list must be from the end of the content to trigger the `onEndReached` callback.
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* Thus a value of 0.5 will trigger `onEndReached` when the end of the content is
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* within half the visible length of the list.
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*/
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onEndReachedThreshold?: ?number,
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/**
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* If provided, a standard RefreshControl will be added for "Pull to Refresh" functionality. Make
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* sure to also set the `refreshing` prop correctly.
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*/
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onRefresh?: ?() => void,
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/**
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* Called when the viewability of rows changes, as defined by the `viewabilityConfig` prop.
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*/
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onViewableItemsChanged?: ?(info: {
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viewableItems: Array<ViewToken>,
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changed: Array<ViewToken>,
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}) => void,
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/**
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* Set this when offset is needed for the loading indicator to show correctly.
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* @platform android
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*/
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progressViewOffset?: number,
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legacyImplementation?: ?boolean,
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/**
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* Set this true while waiting for new data from a refresh.
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*/
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refreshing?: ?boolean,
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/**
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* Note: may have bugs (missing content) in some circumstances - use at your own risk.
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*
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* This may improve scroll performance for large lists.
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*/
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removeClippedSubviews?: boolean,
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/**
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* See `ViewabilityHelper` for flow type and further documentation.
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*/
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viewabilityConfig?: ViewabilityConfig,
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/**
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* List of ViewabilityConfig/onViewableItemsChanged pairs. A specific onViewableItemsChanged
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* will be called when its corresponding ViewabilityConfig's conditions are met.
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*/
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viewabilityConfigCallbackPairs?: Array<ViewabilityConfigCallbackPair>,
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};
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export type Props<ItemT> = RequiredProps<ItemT> &
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OptionalProps<ItemT> &
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VirtualizedListProps;
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const defaultProps = {
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...VirtualizedList.defaultProps,
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numColumns: 1,
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};
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export type DefaultProps = typeof defaultProps;
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/**
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* A performant interface for rendering simple, flat lists, supporting the most handy features:
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*
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* - Fully cross-platform.
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* - Optional horizontal mode.
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* - Configurable viewability callbacks.
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* - Header support.
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* - Footer support.
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* - Separator support.
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* - Pull to Refresh.
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* - Scroll loading.
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* - ScrollToIndex support.
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*
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* If you need section support, use [`<SectionList>`](docs/sectionlist.html).
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*
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* Minimal Example:
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*
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* <FlatList
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* data={[{key: 'a'}, {key: 'b'}]}
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* renderItem={({item}) => <Text>{item.key}</Text>}
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* />
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*
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* More complex, multi-select example demonstrating `PureComponent` usage for perf optimization and avoiding bugs.
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*
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* - By binding the `onPressItem` handler, the props will remain `===` and `PureComponent` will
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* prevent wasteful re-renders unless the actual `id`, `selected`, or `title` props change, even
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* if the components rendered in `MyListItem` did not have such optimizations.
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* - By passing `extraData={this.state}` to `FlatList` we make sure `FlatList` itself will re-render
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* when the `state.selected` changes. Without setting this prop, `FlatList` would not know it
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* needs to re-render any items because it is also a `PureComponent` and the prop comparison will
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* not show any changes.
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* - `keyExtractor` tells the list to use the `id`s for the react keys instead of the default `key` property.
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*
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*
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* class MyListItem extends React.PureComponent {
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* _onPress = () => {
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* this.props.onPressItem(this.props.id);
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* };
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*
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* render() {
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* const textColor = this.props.selected ? "red" : "black";
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* return (
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* <TouchableOpacity onPress={this._onPress}>
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* <View>
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* <Text style={{ color: textColor }}>
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* {this.props.title}
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* </Text>
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* </View>
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* </TouchableOpacity>
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* );
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* }
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* }
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*
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* class MultiSelectList extends React.PureComponent {
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* state = {selected: (new Map(): Map<string, boolean>)};
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*
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* _keyExtractor = (item, index) => item.id;
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*
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* _onPressItem = (id: string) => {
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* // updater functions are preferred for transactional updates
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* this.setState((state) => {
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* // copy the map rather than modifying state.
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* const selected = new Map(state.selected);
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* selected.set(id, !selected.get(id)); // toggle
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* return {selected};
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* });
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* };
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*
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* _renderItem = ({item}) => (
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* <MyListItem
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* id={item.id}
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* onPressItem={this._onPressItem}
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* selected={!!this.state.selected.get(item.id)}
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* title={item.title}
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* />
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* );
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*
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* render() {
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* return (
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* <FlatList
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* data={this.props.data}
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* extraData={this.state}
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* keyExtractor={this._keyExtractor}
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* renderItem={this._renderItem}
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* />
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* );
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* }
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* }
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*
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* This is a convenience wrapper around [`<VirtualizedList>`](docs/virtualizedlist.html),
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* and thus inherits its props (as well as those of `ScrollView`) that aren't explicitly listed
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* here, along with the following caveats:
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*
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* - Internal state is not preserved when content scrolls out of the render window. Make sure all
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* your data is captured in the item data or external stores like Flux, Redux, or Relay.
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* - This is a `PureComponent` which means that it will not re-render if `props` remain shallow-
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* equal. Make sure that everything your `renderItem` function depends on is passed as a prop
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* (e.g. `extraData`) that is not `===` after updates, otherwise your UI may not update on
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* changes. This includes the `data` prop and parent component state.
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* - In order to constrain memory and enable smooth scrolling, content is rendered asynchronously
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* offscreen. This means it's possible to scroll faster than the fill rate ands momentarily see
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* blank content. This is a tradeoff that can be adjusted to suit the needs of each application,
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* and we are working on improving it behind the scenes.
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* - By default, the list looks for a `key` prop on each item and uses that for the React key.
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* Alternatively, you can provide a custom `keyExtractor` prop.
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*
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* Also inherits [ScrollView Props](docs/scrollview.html#props), unless it is nested in another FlatList of same orientation.
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*/
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class FlatList<ItemT> extends React.PureComponent<Props<ItemT>, void> {
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static defaultProps: DefaultProps = defaultProps;
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props: Props<ItemT>;
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/**
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* Scrolls to the end of the content. May be janky without `getItemLayout` prop.
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*/
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scrollToEnd(params?: ?{animated?: ?boolean}) {
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if (this._listRef) {
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this._listRef.scrollToEnd(params);
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}
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}
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/**
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* Scrolls to the item at the specified index such that it is positioned in the viewable area
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* such that `viewPosition` 0 places it at the top, 1 at the bottom, and 0.5 centered in the
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* middle. `viewOffset` is a fixed number of pixels to offset the final target position.
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*
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* Note: cannot scroll to locations outside the render window without specifying the
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* `getItemLayout` prop.
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*/
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scrollToIndex(params: {
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animated?: ?boolean,
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index: number,
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viewOffset?: number,
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viewPosition?: number,
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}) {
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if (this._listRef) {
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// $FlowFixMe Found when typing ListView
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this._listRef.scrollToIndex(params);
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}
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}
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/**
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* Requires linear scan through data - use `scrollToIndex` instead if possible.
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*
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* Note: cannot scroll to locations outside the render window without specifying the
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* `getItemLayout` prop.
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*/
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scrollToItem(params: {
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animated?: ?boolean,
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item: ItemT,
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viewPosition?: number,
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}) {
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if (this._listRef) {
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// $FlowFixMe Found when typing ListView
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this._listRef.scrollToItem(params);
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}
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}
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/**
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* Scroll to a specific content pixel offset in the list.
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*
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* Check out [scrollToOffset](docs/virtualizedlist.html#scrolltooffset) of VirtualizedList
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*/
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scrollToOffset(params: {animated?: ?boolean, offset: number}) {
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if (this._listRef) {
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// $FlowFixMe Found when typing ListView
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this._listRef.scrollToOffset(params);
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}
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}
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/**
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* Tells the list an interaction has occurred, which should trigger viewability calculations, e.g.
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* if `waitForInteractions` is true and the user has not scrolled. This is typically called by
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* taps on items or by navigation actions.
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*/
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recordInteraction() {
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if (this._listRef) {
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// $FlowFixMe Found when typing ListView
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this._listRef.recordInteraction();
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}
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}
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/**
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* Displays the scroll indicators momentarily.
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*
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* @platform ios
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*/
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flashScrollIndicators() {
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if (this._listRef) {
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// $FlowFixMe Found when typing ListView
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this._listRef.flashScrollIndicators();
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}
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}
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/**
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* Provides a handle to the underlying scroll responder.
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*/
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getScrollResponder() {
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if (this._listRef) {
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// $FlowFixMe Found when typing ListView
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return this._listRef.getScrollResponder();
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}
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}
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getScrollableNode() {
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if (this._listRef) {
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// $FlowFixMe Found when typing ListView
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return this._listRef.getScrollableNode();
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}
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}
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setNativeProps(props: {[string]: mixed}) {
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if (this._listRef) {
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this._listRef.setNativeProps(props);
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}
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}
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constructor(props: Props<ItemT>) {
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super(props);
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this._checkProps(this.props);
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if (this.props.viewabilityConfigCallbackPairs) {
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this._virtualizedListPairs = this.props.viewabilityConfigCallbackPairs.map(
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pair => ({
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viewabilityConfig: pair.viewabilityConfig,
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onViewableItemsChanged: this._createOnViewableItemsChanged(
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pair.onViewableItemsChanged,
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),
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}),
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);
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} else if (this.props.onViewableItemsChanged) {
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/* $FlowFixMe(>=0.63.0 site=react_native_fb) This comment suppresses an
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* error found when Flow v0.63 was deployed. To see the error delete this
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* comment and run Flow. */
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this._virtualizedListPairs.push({
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viewabilityConfig: this.props.viewabilityConfig,
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onViewableItemsChanged: this._createOnViewableItemsChanged(
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this.props.onViewableItemsChanged,
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),
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});
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}
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}
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componentDidUpdate(prevProps: Props<ItemT>) {
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invariant(
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prevProps.numColumns === this.props.numColumns,
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'Changing numColumns on the fly is not supported. Change the key prop on FlatList when ' +
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'changing the number of columns to force a fresh render of the component.',
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);
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invariant(
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prevProps.onViewableItemsChanged === this.props.onViewableItemsChanged,
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'Changing onViewableItemsChanged on the fly is not supported',
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);
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invariant(
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!deepDiffer(prevProps.viewabilityConfig, this.props.viewabilityConfig),
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'Changing viewabilityConfig on the fly is not supported',
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);
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invariant(
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prevProps.viewabilityConfigCallbackPairs ===
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this.props.viewabilityConfigCallbackPairs,
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'Changing viewabilityConfigCallbackPairs on the fly is not supported',
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);
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this._checkProps(this.props);
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}
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_hasWarnedLegacy = false;
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_listRef: null | VirtualizedList | ListView | MetroListView;
|
|
_virtualizedListPairs: Array<ViewabilityConfigCallbackPair> = [];
|
|
|
|
_captureRef = ref => {
|
|
this._listRef = ref;
|
|
};
|
|
|
|
_checkProps(props: Props<ItemT>) {
|
|
const {
|
|
getItem,
|
|
getItemCount,
|
|
horizontal,
|
|
legacyImplementation,
|
|
numColumns,
|
|
columnWrapperStyle,
|
|
onViewableItemsChanged,
|
|
viewabilityConfigCallbackPairs,
|
|
} = props;
|
|
invariant(
|
|
!getItem && !getItemCount,
|
|
'FlatList does not support custom data formats.',
|
|
);
|
|
if (numColumns > 1) {
|
|
invariant(!horizontal, 'numColumns does not support horizontal.');
|
|
} else {
|
|
invariant(
|
|
!columnWrapperStyle,
|
|
'columnWrapperStyle not supported for single column lists',
|
|
);
|
|
}
|
|
if (legacyImplementation) {
|
|
invariant(
|
|
numColumns === 1,
|
|
'Legacy list does not support multiple columns.',
|
|
);
|
|
// Warning: may not have full feature parity and is meant more for debugging and performance
|
|
// comparison.
|
|
if (!this._hasWarnedLegacy) {
|
|
console.warn(
|
|
'FlatList: Using legacyImplementation - some features not supported and performance ' +
|
|
'may suffer',
|
|
);
|
|
this._hasWarnedLegacy = true;
|
|
}
|
|
}
|
|
invariant(
|
|
!(onViewableItemsChanged && viewabilityConfigCallbackPairs),
|
|
'FlatList does not support setting both onViewableItemsChanged and ' +
|
|
'viewabilityConfigCallbackPairs.',
|
|
);
|
|
}
|
|
|
|
_getItem = (data: Array<ItemT>, index: number) => {
|
|
const {numColumns} = this.props;
|
|
if (numColumns > 1) {
|
|
const ret = [];
|
|
for (let kk = 0; kk < numColumns; kk++) {
|
|
const item = data[index * numColumns + kk];
|
|
if (item != null) {
|
|
ret.push(item);
|
|
}
|
|
}
|
|
return ret;
|
|
} else {
|
|
return data[index];
|
|
}
|
|
};
|
|
|
|
_getItemCount = (data: ?Array<ItemT>): number => {
|
|
return data ? Math.ceil(data.length / this.props.numColumns) : 0;
|
|
};
|
|
|
|
_keyExtractor = (items: ItemT | Array<ItemT>, index: number) => {
|
|
const {keyExtractor, numColumns} = this.props;
|
|
if (numColumns > 1) {
|
|
invariant(
|
|
Array.isArray(items),
|
|
'FlatList: Encountered internal consistency error, expected each item to consist of an ' +
|
|
'array with 1-%s columns; instead, received a single item.',
|
|
numColumns,
|
|
);
|
|
return items
|
|
.map((it, kk) => keyExtractor(it, index * numColumns + kk))
|
|
.join(':');
|
|
} else {
|
|
/* $FlowFixMe(>=0.63.0 site=react_native_fb) This comment suppresses an
|
|
* error found when Flow v0.63 was deployed. To see the error delete this
|
|
* comment and run Flow. */
|
|
return keyExtractor(items, index);
|
|
}
|
|
};
|
|
|
|
_pushMultiColumnViewable(arr: Array<ViewToken>, v: ViewToken): void {
|
|
const {numColumns, keyExtractor} = this.props;
|
|
v.item.forEach((item, ii) => {
|
|
invariant(v.index != null, 'Missing index!');
|
|
const index = v.index * numColumns + ii;
|
|
arr.push({...v, item, key: keyExtractor(item, index), index});
|
|
});
|
|
}
|
|
|
|
_createOnViewableItemsChanged(
|
|
onViewableItemsChanged: ?(info: {
|
|
viewableItems: Array<ViewToken>,
|
|
changed: Array<ViewToken>,
|
|
}) => void,
|
|
) {
|
|
return (info: {
|
|
viewableItems: Array<ViewToken>,
|
|
changed: Array<ViewToken>,
|
|
}) => {
|
|
const {numColumns} = this.props;
|
|
if (onViewableItemsChanged) {
|
|
if (numColumns > 1) {
|
|
const changed = [];
|
|
const viewableItems = [];
|
|
info.viewableItems.forEach(v =>
|
|
this._pushMultiColumnViewable(viewableItems, v),
|
|
);
|
|
info.changed.forEach(v => this._pushMultiColumnViewable(changed, v));
|
|
onViewableItemsChanged({viewableItems, changed});
|
|
} else {
|
|
onViewableItemsChanged(info);
|
|
}
|
|
}
|
|
};
|
|
}
|
|
|
|
_renderItem = (info: Object) => {
|
|
const {renderItem, numColumns, columnWrapperStyle} = this.props;
|
|
if (numColumns > 1) {
|
|
const {item, index} = info;
|
|
invariant(
|
|
Array.isArray(item),
|
|
'Expected array of items with numColumns > 1',
|
|
);
|
|
return (
|
|
<View
|
|
style={StyleSheet.compose(
|
|
styles.row,
|
|
columnWrapperStyle,
|
|
)}>
|
|
{item.map((it, kk) => {
|
|
const element = renderItem({
|
|
item: it,
|
|
index: index * numColumns + kk,
|
|
separators: info.separators,
|
|
});
|
|
return element && React.cloneElement(element, {key: kk});
|
|
})}
|
|
</View>
|
|
);
|
|
} else {
|
|
return renderItem(info);
|
|
}
|
|
};
|
|
|
|
render() {
|
|
if (this.props.legacyImplementation) {
|
|
return (
|
|
/* $FlowFixMe(>=0.66.0 site=react_native_fb) This comment suppresses an
|
|
* error found when Flow v0.66 was deployed. To see the error delete
|
|
* this comment and run Flow. */
|
|
<MetroListView
|
|
{...this.props}
|
|
/* $FlowFixMe(>=0.66.0 site=react_native_fb) This comment suppresses
|
|
* an error found when Flow v0.66 was deployed. To see the error
|
|
* delete this comment and run Flow. */
|
|
items={this.props.data}
|
|
ref={this._captureRef}
|
|
/>
|
|
);
|
|
} else {
|
|
return (
|
|
<VirtualizedList
|
|
{...this.props}
|
|
renderItem={this._renderItem}
|
|
getItem={this._getItem}
|
|
getItemCount={this._getItemCount}
|
|
keyExtractor={this._keyExtractor}
|
|
ref={this._captureRef}
|
|
viewabilityConfigCallbackPairs={this._virtualizedListPairs}
|
|
/>
|
|
);
|
|
}
|
|
}
|
|
}
|
|
|
|
const styles = StyleSheet.create({
|
|
row: {flexDirection: 'row'},
|
|
});
|
|
|
|
module.exports = FlatList;
|