mirror of
https://github.com/facebook/react-native.git
synced 2025-11-01 09:14:26 +00:00
Tim Yung
494c47360f
Summary: Applies the autofix from the newly introduced `lint/sort-imports` ESLint rule. Changelog: [Internal] Reviewed By: cortinico, skinsshark Differential Revision: D39907798 fbshipit-source-id: 17f5f11b08a5b4bb66286816b78eb26e07e829b8
1643 lines
53 KiB
JavaScript
1643 lines
53 KiB
JavaScript
/**
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* Copyright (c) Meta Platforms, Inc. and affiliates.
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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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import type {ScrollResponderType} from '../Components/ScrollView/ScrollView';
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import type {ViewStyleProp} from '../StyleSheet/StyleSheet';
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import type {LayoutEvent, ScrollEvent} from '../Types/CoreEventTypes';
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import type {ViewToken} from './ViewabilityHelper';
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import type {
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FrameMetricProps,
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Item,
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Props,
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RenderItemProps,
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RenderItemType,
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Separators,
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} from './VirtualizedListProps';
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import ChildListCollection from './ChildListCollection';
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import CellRenderer from './VirtualizedListCellRenderer';
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import {
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VirtualizedListCellContextProvider,
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VirtualizedListContext,
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VirtualizedListContextProvider,
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} from './VirtualizedListContext.js';
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import * as VirtualizedListInjection from './VirtualizedListInjection';
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import {
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computeWindowedRenderLimits,
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keyExtractor as defaultKeyExtractor,
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} from './VirtualizeUtils';
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import * as React from 'react';
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const RefreshControl = require('../Components/RefreshControl/RefreshControl');
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const ScrollView = require('../Components/ScrollView/ScrollView');
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const View = require('../Components/View/View');
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const Batchinator = require('../Interaction/Batchinator');
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const {findNodeHandle} = require('../ReactNative/RendererProxy');
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const flattenStyle = require('../StyleSheet/flattenStyle');
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const StyleSheet = require('../StyleSheet/StyleSheet');
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const infoLog = require('../Utilities/infoLog');
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const FillRateHelper = require('./FillRateHelper');
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const ViewabilityHelper = require('./ViewabilityHelper');
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const invariant = require('invariant');
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export type {RenderItemProps, RenderItemType, Separators};
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const ON_END_REACHED_EPSILON = 0.001;
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let _usedIndexForKey = false;
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let _keylessItemComponentName: string = '';
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type ViewabilityHelperCallbackTuple = {
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viewabilityHelper: ViewabilityHelper,
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onViewableItemsChanged: (info: {
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viewableItems: Array<ViewToken>,
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changed: Array<ViewToken>,
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...
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}) => void,
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...
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};
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type State = {
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first: number,
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last: number,
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};
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/**
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* Default Props Helper Functions
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* Use the following helper functions for default values
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*/
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// horizontalOrDefault(this.props.horizontal)
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function horizontalOrDefault(horizontal: ?boolean) {
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return horizontal ?? false;
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}
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// initialNumToRenderOrDefault(this.props.initialNumToRenderOrDefault)
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function initialNumToRenderOrDefault(initialNumToRender: ?number) {
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return initialNumToRender ?? 10;
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}
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// maxToRenderPerBatchOrDefault(this.props.maxToRenderPerBatch)
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function maxToRenderPerBatchOrDefault(maxToRenderPerBatch: ?number) {
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return maxToRenderPerBatch ?? 10;
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}
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// onEndReachedThresholdOrDefault(this.props.onEndReachedThreshold)
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function onEndReachedThresholdOrDefault(onEndReachedThreshold: ?number) {
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return onEndReachedThreshold ?? 2;
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}
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// scrollEventThrottleOrDefault(this.props.scrollEventThrottle)
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function scrollEventThrottleOrDefault(scrollEventThrottle: ?number) {
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return scrollEventThrottle ?? 50;
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}
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// windowSizeOrDefault(this.props.windowSize)
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function windowSizeOrDefault(windowSize: ?number) {
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return windowSize ?? 21;
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}
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/**
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* Base implementation for the more convenient [`<FlatList>`](https://reactnative.dev/docs/flatlist)
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* and [`<SectionList>`](https://reactnative.dev/docs/sectionlist) components, which are also better
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* documented. In general, this should only really be used if you need more flexibility than
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* `FlatList` provides, e.g. for use with immutable data instead of plain arrays.
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*
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* Virtualization massively improves memory consumption and performance of large lists by
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* maintaining a finite render window of active items and replacing all items outside of the render
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* window with appropriately sized blank space. The window adapts to scrolling behavior, and items
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* are rendered incrementally with low-pri (after any running interactions) if they are far from the
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* visible area, or with hi-pri otherwise to minimize the potential of seeing blank space.
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*
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* Some 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` or `id` 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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* - As an effort to remove defaultProps, use helper functions when referencing certain props
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*
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*/
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class VirtualizedList extends React.PureComponent<Props, State> {
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static contextType: typeof VirtualizedListContext = VirtualizedListContext;
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// scrollToEnd may be janky without getItemLayout prop
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scrollToEnd(params?: ?{animated?: ?boolean, ...}) {
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const animated = params ? params.animated : true;
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const veryLast = this.props.getItemCount(this.props.data) - 1;
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const frame = this.__getFrameMetricsApprox(veryLast);
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const offset = Math.max(
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0,
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frame.offset +
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frame.length +
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this._footerLength -
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this._scrollMetrics.visibleLength,
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);
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if (this._scrollRef == null) {
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return;
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}
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if (this._scrollRef.scrollTo == null) {
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console.warn(
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'No scrollTo method provided. This may be because you have two nested ' +
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'VirtualizedLists with the same orientation, or because you are ' +
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'using a custom component that does not implement scrollTo.',
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);
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return;
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}
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this._scrollRef.scrollTo(
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horizontalOrDefault(this.props.horizontal)
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? {x: offset, animated}
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: {y: offset, animated},
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);
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}
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// scrollToIndex may be janky without getItemLayout prop
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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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}): $FlowFixMe {
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const {
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data,
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horizontal,
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getItemCount,
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getItemLayout,
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onScrollToIndexFailed,
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} = this.props;
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const {animated, index, viewOffset, viewPosition} = params;
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invariant(
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index >= 0,
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`scrollToIndex out of range: requested index ${index} but minimum is 0`,
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);
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invariant(
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getItemCount(data) >= 1,
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`scrollToIndex out of range: item length ${getItemCount(
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data,
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)} but minimum is 1`,
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);
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invariant(
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index < getItemCount(data),
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`scrollToIndex out of range: requested index ${index} is out of 0 to ${
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getItemCount(data) - 1
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}`,
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);
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if (!getItemLayout && index > this._highestMeasuredFrameIndex) {
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invariant(
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!!onScrollToIndexFailed,
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'scrollToIndex should be used in conjunction with getItemLayout or onScrollToIndexFailed, ' +
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'otherwise there is no way to know the location of offscreen indices or handle failures.',
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);
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onScrollToIndexFailed({
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averageItemLength: this._averageCellLength,
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highestMeasuredFrameIndex: this._highestMeasuredFrameIndex,
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index,
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});
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return;
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}
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const frame = this.__getFrameMetricsApprox(index);
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const offset =
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Math.max(
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0,
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frame.offset -
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(viewPosition || 0) *
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(this._scrollMetrics.visibleLength - frame.length),
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) - (viewOffset || 0);
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if (this._scrollRef == null) {
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return;
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}
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if (this._scrollRef.scrollTo == null) {
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console.warn(
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'No scrollTo method provided. This may be because you have two nested ' +
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'VirtualizedLists with the same orientation, or because you are ' +
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'using a custom component that does not implement scrollTo.',
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);
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return;
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}
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this._scrollRef.scrollTo(
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horizontal ? {x: offset, animated} : {y: offset, animated},
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);
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}
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// scrollToItem may be janky without getItemLayout prop. Required linear scan through items -
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// use scrollToIndex instead if possible.
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scrollToItem(params: {
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animated?: ?boolean,
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item: Item,
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viewPosition?: number,
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...
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}) {
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const {item} = params;
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const {data, getItem, getItemCount} = this.props;
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const itemCount = getItemCount(data);
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for (let index = 0; index < itemCount; index++) {
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if (getItem(data, index) === item) {
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this.scrollToIndex({...params, index});
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break;
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}
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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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* Param `offset` expects the offset to scroll to.
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* In case of `horizontal` is true, the offset is the x-value,
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* in any other case the offset is the y-value.
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*
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* Param `animated` (`true` by default) defines whether the list
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* should do an animation while scrolling.
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*/
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scrollToOffset(params: {animated?: ?boolean, offset: number, ...}) {
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const {animated, offset} = params;
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if (this._scrollRef == null) {
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return;
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}
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if (this._scrollRef.scrollTo == null) {
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console.warn(
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'No scrollTo method provided. This may be because you have two nested ' +
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'VirtualizedLists with the same orientation, or because you are ' +
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'using a custom component that does not implement scrollTo.',
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);
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return;
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}
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this._scrollRef.scrollTo(
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horizontalOrDefault(this.props.horizontal)
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? {x: offset, animated}
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: {y: offset, animated},
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);
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}
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recordInteraction() {
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this._nestedChildLists.forEach(childList => {
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childList.recordInteraction();
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});
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this._viewabilityTuples.forEach(t => {
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t.viewabilityHelper.recordInteraction();
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});
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this._updateViewableItems(this.props.data);
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}
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flashScrollIndicators() {
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if (this._scrollRef == null) {
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return;
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}
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this._scrollRef.flashScrollIndicators();
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}
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/**
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* Provides a handle to the underlying scroll responder.
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* Note that `this._scrollRef` might not be a `ScrollView`, so we
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* need to check that it responds to `getScrollResponder` before calling it.
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*/
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getScrollResponder(): ?ScrollResponderType {
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if (this._scrollRef && this._scrollRef.getScrollResponder) {
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return this._scrollRef.getScrollResponder();
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}
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}
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getScrollableNode(): ?number {
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if (this._scrollRef && this._scrollRef.getScrollableNode) {
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return this._scrollRef.getScrollableNode();
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} else {
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return findNodeHandle(this._scrollRef);
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}
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}
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getScrollRef():
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| ?React.ElementRef<typeof ScrollView>
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| ?React.ElementRef<typeof View> {
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if (this._scrollRef && this._scrollRef.getScrollRef) {
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return this._scrollRef.getScrollRef();
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} else {
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return this._scrollRef;
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}
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}
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setNativeProps(props: Object) {
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if (this._scrollRef) {
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this._scrollRef.setNativeProps(props);
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}
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}
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_getCellKey(): string {
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return this.context?.cellKey || 'rootList';
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}
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// $FlowFixMe[missing-local-annot]
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_getScrollMetrics = () => {
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return this._scrollMetrics;
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};
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hasMore(): boolean {
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return this._hasMore;
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}
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// $FlowFixMe[missing-local-annot]
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_getOutermostParentListRef = () => {
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if (this._isNestedWithSameOrientation()) {
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return this.context.getOutermostParentListRef();
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} else {
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return this;
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}
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};
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_registerAsNestedChild = (childList: {
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cellKey: string,
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ref: React.ElementRef<typeof React.Component>,
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}): void => {
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const listRef = ((childList.ref: any): VirtualizedList);
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this._nestedChildLists.add(listRef, childList.cellKey);
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if (this._hasInteracted) {
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listRef.recordInteraction();
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}
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};
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_unregisterAsNestedChild = (childList: {
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ref: React.ElementRef<typeof React.Component>,
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}): void => {
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const listRef = ((childList.ref: any): VirtualizedList);
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this._nestedChildLists.remove(listRef);
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};
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state: State;
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constructor(props: Props) {
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super(props);
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invariant(
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// $FlowFixMe[prop-missing]
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!props.onScroll || !props.onScroll.__isNative,
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'Components based on VirtualizedList must be wrapped with Animated.createAnimatedComponent ' +
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'to support native onScroll events with useNativeDriver',
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);
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invariant(
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windowSizeOrDefault(props.windowSize) > 0,
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'VirtualizedList: The windowSize prop must be present and set to a value greater than 0.',
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);
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this._fillRateHelper = new FillRateHelper(this._getFrameMetrics);
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this._updateCellsToRenderBatcher = new Batchinator(
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this._updateCellsToRender,
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this.props.updateCellsBatchingPeriod ?? 50,
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);
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if (this.props.viewabilityConfigCallbackPairs) {
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this._viewabilityTuples = this.props.viewabilityConfigCallbackPairs.map(
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pair => ({
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viewabilityHelper: new ViewabilityHelper(pair.viewabilityConfig),
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onViewableItemsChanged: pair.onViewableItemsChanged,
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}),
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);
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} else {
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const {onViewableItemsChanged, viewabilityConfig} = this.props;
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if (onViewableItemsChanged) {
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this._viewabilityTuples.push({
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viewabilityHelper: new ViewabilityHelper(viewabilityConfig),
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onViewableItemsChanged: onViewableItemsChanged,
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});
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}
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}
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invariant(
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!this.context,
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'Unexpectedly saw VirtualizedListContext available in ctor',
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);
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this.state = {
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first: this.props.initialScrollIndex || 0,
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last:
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Math.min(
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this.props.getItemCount(this.props.data),
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(this.props.initialScrollIndex || 0) +
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initialNumToRenderOrDefault(this.props.initialNumToRender),
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) - 1,
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};
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}
|
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|
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componentDidMount() {
|
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if (this._isNestedWithSameOrientation()) {
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this.context.registerAsNestedChild({
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ref: this,
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cellKey: this.context.cellKey,
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});
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}
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}
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componentWillUnmount() {
|
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if (this._isNestedWithSameOrientation()) {
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this.context.unregisterAsNestedChild({ref: this});
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}
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this._updateViewableItems(null);
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this._updateCellsToRenderBatcher.dispose({abort: true});
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this._viewabilityTuples.forEach(tuple => {
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tuple.viewabilityHelper.dispose();
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});
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this._fillRateHelper.deactivateAndFlush();
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}
|
|
|
|
static getDerivedStateFromProps(newProps: Props, prevState: State): State {
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|
const {data, getItemCount} = newProps;
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|
const maxToRenderPerBatch = maxToRenderPerBatchOrDefault(
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newProps.maxToRenderPerBatch,
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);
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// first and last could be stale (e.g. if a new, shorter items props is passed in), so we make
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// sure we're rendering a reasonable range here.
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return {
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first: Math.max(
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0,
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Math.min(prevState.first, getItemCount(data) - 1 - maxToRenderPerBatch),
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),
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last: Math.max(0, Math.min(prevState.last, getItemCount(data) - 1)),
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};
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}
|
|
|
|
_pushCells(
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cells: Array<Object>,
|
|
stickyHeaderIndices: Array<number>,
|
|
stickyIndicesFromProps: Set<number>,
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first: number,
|
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last: number,
|
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inversionStyle: ViewStyleProp,
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) {
|
|
const {
|
|
CellRendererComponent,
|
|
ItemSeparatorComponent,
|
|
ListHeaderComponent,
|
|
ListItemComponent,
|
|
data,
|
|
debug,
|
|
getItem,
|
|
getItemCount,
|
|
getItemLayout,
|
|
horizontal,
|
|
renderItem,
|
|
} = this.props;
|
|
const stickyOffset = ListHeaderComponent ? 1 : 0;
|
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const end = getItemCount(data) - 1;
|
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let prevCellKey;
|
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last = Math.min(end, last);
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for (let ii = first; ii <= last; ii++) {
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const item = getItem(data, ii);
|
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const key = this._keyExtractor(item, ii);
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this._indicesToKeys.set(ii, key);
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if (stickyIndicesFromProps.has(ii + stickyOffset)) {
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stickyHeaderIndices.push(cells.length);
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}
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cells.push(
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<CellRenderer
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CellRendererComponent={CellRendererComponent}
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|
ItemSeparatorComponent={ii < end ? ItemSeparatorComponent : undefined}
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|
ListItemComponent={ListItemComponent}
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cellKey={key}
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debug={debug}
|
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fillRateHelper={this._fillRateHelper}
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getItemLayout={getItemLayout}
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horizontal={horizontal}
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index={ii}
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inversionStyle={inversionStyle}
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item={item}
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key={key}
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prevCellKey={prevCellKey}
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onCellLayout={this._onCellLayout}
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onUpdateSeparators={this._onUpdateSeparators}
|
|
onUnmount={this._onCellUnmount}
|
|
ref={ref => {
|
|
this._cellRefs[key] = ref;
|
|
}}
|
|
renderItem={renderItem}
|
|
/>,
|
|
);
|
|
prevCellKey = key;
|
|
}
|
|
}
|
|
|
|
_onUpdateSeparators = (keys: Array<?string>, newProps: Object) => {
|
|
keys.forEach(key => {
|
|
const ref = key != null && this._cellRefs[key];
|
|
ref && ref.updateSeparatorProps(newProps);
|
|
});
|
|
};
|
|
|
|
_isVirtualizationDisabled(): boolean {
|
|
return this.props.disableVirtualization || false;
|
|
}
|
|
|
|
_isNestedWithSameOrientation(): boolean {
|
|
const nestedContext = this.context;
|
|
return !!(
|
|
nestedContext &&
|
|
!!nestedContext.horizontal === horizontalOrDefault(this.props.horizontal)
|
|
);
|
|
}
|
|
|
|
_getSpacerKey = (isVertical: boolean): string =>
|
|
isVertical ? 'height' : 'width';
|
|
|
|
// $FlowFixMe[missing-local-annot]
|
|
_keyExtractor(item: Item, index: number) {
|
|
if (this.props.keyExtractor != null) {
|
|
return this.props.keyExtractor(item, index);
|
|
}
|
|
|
|
const key = defaultKeyExtractor(item, index);
|
|
if (key === String(index)) {
|
|
_usedIndexForKey = true;
|
|
if (item.type && item.type.displayName) {
|
|
_keylessItemComponentName = item.type.displayName;
|
|
}
|
|
}
|
|
return key;
|
|
}
|
|
|
|
render(): React.Node {
|
|
if (__DEV__) {
|
|
const flatStyles = flattenStyle(this.props.contentContainerStyle);
|
|
if (flatStyles != null && flatStyles.flexWrap === 'wrap') {
|
|
console.warn(
|
|
'`flexWrap: `wrap`` is not supported with the `VirtualizedList` components.' +
|
|
'Consider using `numColumns` with `FlatList` instead.',
|
|
);
|
|
}
|
|
}
|
|
const {ListEmptyComponent, ListFooterComponent, ListHeaderComponent} =
|
|
this.props;
|
|
const {data, horizontal} = this.props;
|
|
const isVirtualizationDisabled = this._isVirtualizationDisabled();
|
|
const inversionStyle = this.props.inverted
|
|
? horizontalOrDefault(this.props.horizontal)
|
|
? styles.horizontallyInverted
|
|
: styles.verticallyInverted
|
|
: null;
|
|
const cells = [];
|
|
const stickyIndicesFromProps = new Set(this.props.stickyHeaderIndices);
|
|
const stickyHeaderIndices = [];
|
|
if (ListHeaderComponent) {
|
|
if (stickyIndicesFromProps.has(0)) {
|
|
stickyHeaderIndices.push(0);
|
|
}
|
|
const element = React.isValidElement(ListHeaderComponent) ? (
|
|
ListHeaderComponent
|
|
) : (
|
|
// $FlowFixMe[not-a-component]
|
|
// $FlowFixMe[incompatible-type-arg]
|
|
<ListHeaderComponent />
|
|
);
|
|
cells.push(
|
|
<VirtualizedListCellContextProvider
|
|
cellKey={this._getCellKey() + '-header'}
|
|
key="$header">
|
|
<View
|
|
onLayout={this._onLayoutHeader}
|
|
style={StyleSheet.compose(
|
|
inversionStyle,
|
|
this.props.ListHeaderComponentStyle,
|
|
)}>
|
|
{
|
|
// $FlowFixMe[incompatible-type] - Typing ReactNativeComponent revealed errors
|
|
element
|
|
}
|
|
</View>
|
|
</VirtualizedListCellContextProvider>,
|
|
);
|
|
}
|
|
const itemCount = this.props.getItemCount(data);
|
|
if (itemCount > 0) {
|
|
_usedIndexForKey = false;
|
|
_keylessItemComponentName = '';
|
|
const spacerKey = this._getSpacerKey(!horizontal);
|
|
const lastInitialIndex = this.props.initialScrollIndex
|
|
? -1
|
|
: initialNumToRenderOrDefault(this.props.initialNumToRender) - 1;
|
|
const {first, last} = this.state;
|
|
this._pushCells(
|
|
cells,
|
|
stickyHeaderIndices,
|
|
stickyIndicesFromProps,
|
|
0,
|
|
lastInitialIndex,
|
|
inversionStyle,
|
|
);
|
|
const firstAfterInitial = Math.max(lastInitialIndex + 1, first);
|
|
if (!isVirtualizationDisabled && first > lastInitialIndex + 1) {
|
|
let insertedStickySpacer = false;
|
|
if (stickyIndicesFromProps.size > 0) {
|
|
const stickyOffset = ListHeaderComponent ? 1 : 0;
|
|
// See if there are any sticky headers in the virtualized space that we need to render.
|
|
for (let ii = firstAfterInitial - 1; ii > lastInitialIndex; ii--) {
|
|
if (stickyIndicesFromProps.has(ii + stickyOffset)) {
|
|
const initBlock = this.__getFrameMetricsApprox(lastInitialIndex);
|
|
const stickyBlock = this.__getFrameMetricsApprox(ii);
|
|
const leadSpace =
|
|
stickyBlock.offset -
|
|
initBlock.offset -
|
|
(this.props.initialScrollIndex ? 0 : initBlock.length);
|
|
cells.push(
|
|
<View key="$sticky_lead" style={{[spacerKey]: leadSpace}} />,
|
|
);
|
|
this._pushCells(
|
|
cells,
|
|
stickyHeaderIndices,
|
|
stickyIndicesFromProps,
|
|
ii,
|
|
ii,
|
|
inversionStyle,
|
|
);
|
|
const trailSpace =
|
|
this.__getFrameMetricsApprox(first).offset -
|
|
(stickyBlock.offset + stickyBlock.length);
|
|
cells.push(
|
|
<View key="$sticky_trail" style={{[spacerKey]: trailSpace}} />,
|
|
);
|
|
insertedStickySpacer = true;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
if (!insertedStickySpacer) {
|
|
const initBlock = this.__getFrameMetricsApprox(lastInitialIndex);
|
|
const firstSpace =
|
|
this.__getFrameMetricsApprox(first).offset -
|
|
(initBlock.offset + initBlock.length);
|
|
cells.push(
|
|
<View key="$lead_spacer" style={{[spacerKey]: firstSpace}} />,
|
|
);
|
|
}
|
|
}
|
|
this._pushCells(
|
|
cells,
|
|
stickyHeaderIndices,
|
|
stickyIndicesFromProps,
|
|
firstAfterInitial,
|
|
last,
|
|
inversionStyle,
|
|
);
|
|
if (!this._hasWarned.keys && _usedIndexForKey) {
|
|
console.warn(
|
|
'VirtualizedList: missing keys for items, make sure to specify a key or id property on each ' +
|
|
'item or provide a custom keyExtractor.',
|
|
_keylessItemComponentName,
|
|
);
|
|
this._hasWarned.keys = true;
|
|
}
|
|
if (!isVirtualizationDisabled && last < itemCount - 1) {
|
|
const lastFrame = this.__getFrameMetricsApprox(last);
|
|
// Without getItemLayout, we limit our tail spacer to the _highestMeasuredFrameIndex to
|
|
// prevent the user for hyperscrolling into un-measured area because otherwise content will
|
|
// likely jump around as it renders in above the viewport.
|
|
const end = this.props.getItemLayout
|
|
? itemCount - 1
|
|
: Math.min(itemCount - 1, this._highestMeasuredFrameIndex);
|
|
const endFrame = this.__getFrameMetricsApprox(end);
|
|
const tailSpacerLength =
|
|
endFrame.offset +
|
|
endFrame.length -
|
|
(lastFrame.offset + lastFrame.length);
|
|
cells.push(
|
|
<View key="$tail_spacer" style={{[spacerKey]: tailSpacerLength}} />,
|
|
);
|
|
}
|
|
} else if (ListEmptyComponent) {
|
|
const element: React.Element<any> = ((React.isValidElement(
|
|
ListEmptyComponent,
|
|
) ? (
|
|
ListEmptyComponent
|
|
) : (
|
|
// $FlowFixMe[not-a-component]
|
|
// $FlowFixMe[incompatible-type-arg]
|
|
<ListEmptyComponent />
|
|
)): any);
|
|
cells.push(
|
|
React.cloneElement(element, {
|
|
key: '$empty',
|
|
onLayout: event => {
|
|
this._onLayoutEmpty(event);
|
|
if (element.props.onLayout) {
|
|
element.props.onLayout(event);
|
|
}
|
|
},
|
|
style: StyleSheet.compose(inversionStyle, element.props.style),
|
|
}),
|
|
);
|
|
}
|
|
if (ListFooterComponent) {
|
|
const element = React.isValidElement(ListFooterComponent) ? (
|
|
ListFooterComponent
|
|
) : (
|
|
// $FlowFixMe[not-a-component]
|
|
// $FlowFixMe[incompatible-type-arg]
|
|
<ListFooterComponent />
|
|
);
|
|
cells.push(
|
|
<VirtualizedListCellContextProvider
|
|
cellKey={this._getFooterCellKey()}
|
|
key="$footer">
|
|
<View
|
|
onLayout={this._onLayoutFooter}
|
|
style={StyleSheet.compose(
|
|
inversionStyle,
|
|
this.props.ListFooterComponentStyle,
|
|
)}>
|
|
{
|
|
// $FlowFixMe[incompatible-type] - Typing ReactNativeComponent revealed errors
|
|
element
|
|
}
|
|
</View>
|
|
</VirtualizedListCellContextProvider>,
|
|
);
|
|
}
|
|
const scrollProps = {
|
|
...this.props,
|
|
onContentSizeChange: this._onContentSizeChange,
|
|
onLayout: this._onLayout,
|
|
onScroll: this._onScroll,
|
|
onScrollBeginDrag: this._onScrollBeginDrag,
|
|
onScrollEndDrag: this._onScrollEndDrag,
|
|
onMomentumScrollBegin: this._onMomentumScrollBegin,
|
|
onMomentumScrollEnd: this._onMomentumScrollEnd,
|
|
scrollEventThrottle: scrollEventThrottleOrDefault(
|
|
this.props.scrollEventThrottle,
|
|
), // TODO: Android support
|
|
invertStickyHeaders:
|
|
this.props.invertStickyHeaders !== undefined
|
|
? this.props.invertStickyHeaders
|
|
: this.props.inverted,
|
|
stickyHeaderIndices,
|
|
style: inversionStyle
|
|
? [inversionStyle, this.props.style]
|
|
: this.props.style,
|
|
};
|
|
|
|
this._hasMore =
|
|
this.state.last < this.props.getItemCount(this.props.data) - 1;
|
|
|
|
const innerRet = (
|
|
<VirtualizedListContextProvider
|
|
value={{
|
|
cellKey: null,
|
|
getScrollMetrics: this._getScrollMetrics,
|
|
horizontal: horizontalOrDefault(this.props.horizontal),
|
|
getOutermostParentListRef: this._getOutermostParentListRef,
|
|
registerAsNestedChild: this._registerAsNestedChild,
|
|
unregisterAsNestedChild: this._unregisterAsNestedChild,
|
|
}}>
|
|
{React.cloneElement(
|
|
(
|
|
this.props.renderScrollComponent ||
|
|
this._defaultRenderScrollComponent
|
|
)(scrollProps),
|
|
{
|
|
ref: this._captureScrollRef,
|
|
},
|
|
cells,
|
|
)}
|
|
</VirtualizedListContextProvider>
|
|
);
|
|
let ret: React.Node = innerRet;
|
|
if (__DEV__) {
|
|
ret = (
|
|
<ScrollView.Context.Consumer>
|
|
{scrollContext => {
|
|
if (
|
|
scrollContext != null &&
|
|
!scrollContext.horizontal ===
|
|
!horizontalOrDefault(this.props.horizontal) &&
|
|
!this._hasWarned.nesting &&
|
|
this.context == null
|
|
) {
|
|
// TODO (T46547044): use React.warn once 16.9 is sync'd: https://github.com/facebook/react/pull/15170
|
|
console.error(
|
|
'VirtualizedLists should never be nested inside plain ScrollViews with the same ' +
|
|
'orientation because it can break windowing and other functionality - use another ' +
|
|
'VirtualizedList-backed container instead.',
|
|
);
|
|
this._hasWarned.nesting = true;
|
|
}
|
|
return innerRet;
|
|
}}
|
|
</ScrollView.Context.Consumer>
|
|
);
|
|
}
|
|
if (this.props.debug) {
|
|
return (
|
|
<View style={styles.debug}>
|
|
{ret}
|
|
{this._renderDebugOverlay()}
|
|
</View>
|
|
);
|
|
} else {
|
|
return ret;
|
|
}
|
|
}
|
|
|
|
componentDidUpdate(prevProps: Props) {
|
|
const {data, extraData} = this.props;
|
|
if (data !== prevProps.data || extraData !== prevProps.extraData) {
|
|
// clear the viewableIndices cache to also trigger
|
|
// the onViewableItemsChanged callback with the new data
|
|
this._viewabilityTuples.forEach(tuple => {
|
|
tuple.viewabilityHelper.resetViewableIndices();
|
|
});
|
|
}
|
|
// The `this._hiPriInProgress` is guaranteeing a hiPri cell update will only happen
|
|
// once per fiber update. The `_scheduleCellsToRenderUpdate` will set it to true
|
|
// if a hiPri update needs to perform. If `componentDidUpdate` is triggered with
|
|
// `this._hiPriInProgress=true`, means it's triggered by the hiPri update. The
|
|
// `_scheduleCellsToRenderUpdate` will check this condition and not perform
|
|
// another hiPri update.
|
|
const hiPriInProgress = this._hiPriInProgress;
|
|
this._scheduleCellsToRenderUpdate();
|
|
// Make sure setting `this._hiPriInProgress` back to false after `componentDidUpdate`
|
|
// is triggered with `this._hiPriInProgress = true`
|
|
if (hiPriInProgress) {
|
|
this._hiPriInProgress = false;
|
|
}
|
|
}
|
|
|
|
_averageCellLength = 0;
|
|
_cellRefs: {[string]: null | CellRenderer<any>} = {};
|
|
_fillRateHelper: FillRateHelper;
|
|
_frames: {
|
|
[string]: {
|
|
inLayout?: boolean,
|
|
index: number,
|
|
length: number,
|
|
offset: number,
|
|
},
|
|
} = {};
|
|
_footerLength = 0;
|
|
// Used for preventing scrollToIndex from being called multiple times for initialScrollIndex
|
|
_hasTriggeredInitialScrollToIndex = false;
|
|
_hasInteracted = false;
|
|
_hasMore = false;
|
|
_hasWarned: {[string]: boolean} = {};
|
|
_headerLength = 0;
|
|
_hiPriInProgress: boolean = false; // flag to prevent infinite hiPri cell limit update
|
|
_highestMeasuredFrameIndex = 0;
|
|
_indicesToKeys: Map<number, string> = new Map();
|
|
_nestedChildLists: ChildListCollection<VirtualizedList> =
|
|
new ChildListCollection();
|
|
_offsetFromParentVirtualizedList: number = 0;
|
|
_prevParentOffset: number = 0;
|
|
// $FlowFixMe[missing-local-annot]
|
|
_scrollMetrics = {
|
|
contentLength: 0,
|
|
dOffset: 0,
|
|
dt: 10,
|
|
offset: 0,
|
|
timestamp: 0,
|
|
velocity: 0,
|
|
visibleLength: 0,
|
|
zoomScale: 1,
|
|
};
|
|
_scrollRef: ?React.ElementRef<any> = null;
|
|
_sentEndForContentLength = 0;
|
|
_totalCellLength = 0;
|
|
_totalCellsMeasured = 0;
|
|
_updateCellsToRenderBatcher: Batchinator;
|
|
_viewabilityTuples: Array<ViewabilityHelperCallbackTuple> = [];
|
|
|
|
/* $FlowFixMe[missing-local-annot] The type annotation(s) required by Flow's
|
|
* LTI update could not be added via codemod */
|
|
_captureScrollRef = ref => {
|
|
this._scrollRef = ref;
|
|
};
|
|
|
|
_computeBlankness() {
|
|
this._fillRateHelper.computeBlankness(
|
|
this.props,
|
|
this.state,
|
|
this._scrollMetrics,
|
|
);
|
|
}
|
|
|
|
/* $FlowFixMe[missing-local-annot] The type annotation(s) required by Flow's
|
|
* LTI update could not be added via codemod */
|
|
_defaultRenderScrollComponent = props => {
|
|
const onRefresh = props.onRefresh;
|
|
if (this._isNestedWithSameOrientation()) {
|
|
// $FlowFixMe[prop-missing] - Typing ReactNativeComponent revealed errors
|
|
return <View {...props} />;
|
|
} else if (onRefresh) {
|
|
invariant(
|
|
typeof props.refreshing === 'boolean',
|
|
'`refreshing` prop must be set as a boolean in order to use `onRefresh`, but got `' +
|
|
JSON.stringify(props.refreshing ?? 'undefined') +
|
|
'`',
|
|
);
|
|
return (
|
|
// $FlowFixMe[prop-missing] Invalid prop usage
|
|
// $FlowFixMe[incompatible-use]
|
|
<ScrollView
|
|
{...props}
|
|
refreshControl={
|
|
props.refreshControl == null ? (
|
|
<RefreshControl
|
|
// $FlowFixMe[incompatible-type]
|
|
refreshing={props.refreshing}
|
|
onRefresh={onRefresh}
|
|
progressViewOffset={props.progressViewOffset}
|
|
/>
|
|
) : (
|
|
props.refreshControl
|
|
)
|
|
}
|
|
/>
|
|
);
|
|
} else {
|
|
// $FlowFixMe[prop-missing] Invalid prop usage
|
|
// $FlowFixMe[incompatible-use]
|
|
return <ScrollView {...props} />;
|
|
}
|
|
};
|
|
|
|
_onCellLayout = (e: LayoutEvent, cellKey: string, index: number): void => {
|
|
const layout = e.nativeEvent.layout;
|
|
const next = {
|
|
offset: this._selectOffset(layout),
|
|
length: this._selectLength(layout),
|
|
index,
|
|
inLayout: true,
|
|
};
|
|
const curr = this._frames[cellKey];
|
|
if (
|
|
!curr ||
|
|
next.offset !== curr.offset ||
|
|
next.length !== curr.length ||
|
|
index !== curr.index
|
|
) {
|
|
this._totalCellLength += next.length - (curr ? curr.length : 0);
|
|
this._totalCellsMeasured += curr ? 0 : 1;
|
|
this._averageCellLength =
|
|
this._totalCellLength / this._totalCellsMeasured;
|
|
this._frames[cellKey] = next;
|
|
this._highestMeasuredFrameIndex = Math.max(
|
|
this._highestMeasuredFrameIndex,
|
|
index,
|
|
);
|
|
this._scheduleCellsToRenderUpdate();
|
|
} else {
|
|
this._frames[cellKey].inLayout = true;
|
|
}
|
|
|
|
this._triggerRemeasureForChildListsInCell(cellKey);
|
|
|
|
this._computeBlankness();
|
|
this._updateViewableItems(this.props.data);
|
|
};
|
|
|
|
_onCellUnmount = (cellKey: string) => {
|
|
const curr = this._frames[cellKey];
|
|
if (curr) {
|
|
this._frames[cellKey] = {...curr, inLayout: false};
|
|
}
|
|
};
|
|
|
|
_triggerRemeasureForChildListsInCell(cellKey: string): void {
|
|
this._nestedChildLists.forEachInCell(cellKey, childList => {
|
|
childList.measureLayoutRelativeToContainingList();
|
|
});
|
|
}
|
|
|
|
measureLayoutRelativeToContainingList(): void {
|
|
// TODO (T35574538): findNodeHandle sometimes crashes with "Unable to find
|
|
// node on an unmounted component" during scrolling
|
|
try {
|
|
if (!this._scrollRef) {
|
|
return;
|
|
}
|
|
// We are assuming that getOutermostParentListRef().getScrollRef()
|
|
// is a non-null reference to a ScrollView
|
|
this._scrollRef.measureLayout(
|
|
this.context.getOutermostParentListRef().getScrollRef(),
|
|
(x, y, width, height) => {
|
|
this._offsetFromParentVirtualizedList = this._selectOffset({x, y});
|
|
this._scrollMetrics.contentLength = this._selectLength({
|
|
width,
|
|
height,
|
|
});
|
|
const scrollMetrics = this._convertParentScrollMetrics(
|
|
this.context.getScrollMetrics(),
|
|
);
|
|
|
|
const metricsChanged =
|
|
this._scrollMetrics.visibleLength !== scrollMetrics.visibleLength ||
|
|
this._scrollMetrics.offset !== scrollMetrics.offset;
|
|
|
|
if (metricsChanged) {
|
|
this._scrollMetrics.visibleLength = scrollMetrics.visibleLength;
|
|
this._scrollMetrics.offset = scrollMetrics.offset;
|
|
|
|
// If metrics of the scrollView changed, then we triggered remeasure for child list
|
|
// to ensure VirtualizedList has the right information.
|
|
this._nestedChildLists.forEach(childList => {
|
|
childList.measureLayoutRelativeToContainingList();
|
|
});
|
|
}
|
|
},
|
|
error => {
|
|
console.warn(
|
|
"VirtualizedList: Encountered an error while measuring a list's" +
|
|
' offset from its containing VirtualizedList.',
|
|
);
|
|
},
|
|
);
|
|
} catch (error) {
|
|
console.warn(
|
|
'measureLayoutRelativeToContainingList threw an error',
|
|
error.stack,
|
|
);
|
|
}
|
|
}
|
|
|
|
_onLayout = (e: LayoutEvent) => {
|
|
if (this._isNestedWithSameOrientation()) {
|
|
// Need to adjust our scroll metrics to be relative to our containing
|
|
// VirtualizedList before we can make claims about list item viewability
|
|
this.measureLayoutRelativeToContainingList();
|
|
} else {
|
|
this._scrollMetrics.visibleLength = this._selectLength(
|
|
e.nativeEvent.layout,
|
|
);
|
|
}
|
|
this.props.onLayout && this.props.onLayout(e);
|
|
this._scheduleCellsToRenderUpdate();
|
|
this._maybeCallOnEndReached();
|
|
};
|
|
|
|
_onLayoutEmpty = (e: LayoutEvent) => {
|
|
this.props.onLayout && this.props.onLayout(e);
|
|
};
|
|
|
|
_getFooterCellKey(): string {
|
|
return this._getCellKey() + '-footer';
|
|
}
|
|
|
|
_onLayoutFooter = (e: LayoutEvent) => {
|
|
this._triggerRemeasureForChildListsInCell(this._getFooterCellKey());
|
|
this._footerLength = this._selectLength(e.nativeEvent.layout);
|
|
};
|
|
|
|
_onLayoutHeader = (e: LayoutEvent) => {
|
|
this._headerLength = this._selectLength(e.nativeEvent.layout);
|
|
};
|
|
|
|
// $FlowFixMe[missing-local-annot]
|
|
_renderDebugOverlay() {
|
|
const normalize =
|
|
this._scrollMetrics.visibleLength /
|
|
(this._scrollMetrics.contentLength || 1);
|
|
const framesInLayout = [];
|
|
const itemCount = this.props.getItemCount(this.props.data);
|
|
for (let ii = 0; ii < itemCount; ii++) {
|
|
const frame = this.__getFrameMetricsApprox(ii);
|
|
/* $FlowFixMe[prop-missing] (>=0.68.0 site=react_native_fb) This comment
|
|
* suppresses an error found when Flow v0.68 was deployed. To see the
|
|
* error delete this comment and run Flow. */
|
|
if (frame.inLayout) {
|
|
framesInLayout.push(frame);
|
|
}
|
|
}
|
|
const windowTop = this.__getFrameMetricsApprox(this.state.first).offset;
|
|
const frameLast = this.__getFrameMetricsApprox(this.state.last);
|
|
const windowLen = frameLast.offset + frameLast.length - windowTop;
|
|
const visTop = this._scrollMetrics.offset;
|
|
const visLen = this._scrollMetrics.visibleLength;
|
|
|
|
return (
|
|
<View style={[styles.debugOverlayBase, styles.debugOverlay]}>
|
|
{framesInLayout.map((f, ii) => (
|
|
<View
|
|
key={'f' + ii}
|
|
style={[
|
|
styles.debugOverlayBase,
|
|
styles.debugOverlayFrame,
|
|
{
|
|
top: f.offset * normalize,
|
|
height: f.length * normalize,
|
|
},
|
|
]}
|
|
/>
|
|
))}
|
|
<View
|
|
style={[
|
|
styles.debugOverlayBase,
|
|
styles.debugOverlayFrameLast,
|
|
{
|
|
top: windowTop * normalize,
|
|
height: windowLen * normalize,
|
|
},
|
|
]}
|
|
/>
|
|
<View
|
|
style={[
|
|
styles.debugOverlayBase,
|
|
styles.debugOverlayFrameVis,
|
|
{
|
|
top: visTop * normalize,
|
|
height: visLen * normalize,
|
|
},
|
|
]}
|
|
/>
|
|
</View>
|
|
);
|
|
}
|
|
|
|
_selectLength(
|
|
metrics: $ReadOnly<{
|
|
height: number,
|
|
width: number,
|
|
...
|
|
}>,
|
|
): number {
|
|
return !horizontalOrDefault(this.props.horizontal)
|
|
? metrics.height
|
|
: metrics.width;
|
|
}
|
|
|
|
_selectOffset(
|
|
metrics: $ReadOnly<{
|
|
x: number,
|
|
y: number,
|
|
...
|
|
}>,
|
|
): number {
|
|
return !horizontalOrDefault(this.props.horizontal) ? metrics.y : metrics.x;
|
|
}
|
|
|
|
_maybeCallOnEndReached() {
|
|
const {data, getItemCount, onEndReached, onEndReachedThreshold} =
|
|
this.props;
|
|
const {contentLength, visibleLength, offset} = this._scrollMetrics;
|
|
let distanceFromEnd = contentLength - visibleLength - offset;
|
|
|
|
// Especially when oERT is zero it's necessary to 'floor' very small distanceFromEnd values to be 0
|
|
// since debouncing causes us to not fire this event for every single "pixel" we scroll and can thus
|
|
// be at the "end" of the list with a distanceFromEnd approximating 0 but not quite there.
|
|
if (distanceFromEnd < ON_END_REACHED_EPSILON) {
|
|
distanceFromEnd = 0;
|
|
}
|
|
|
|
// TODO: T121172172 Look into why we're "defaulting" to a threshold of 2 when oERT is not present
|
|
const threshold =
|
|
onEndReachedThreshold != null ? onEndReachedThreshold * visibleLength : 2;
|
|
if (
|
|
onEndReached &&
|
|
this.state.last === getItemCount(data) - 1 &&
|
|
distanceFromEnd <= threshold &&
|
|
this._scrollMetrics.contentLength !== this._sentEndForContentLength
|
|
) {
|
|
// Only call onEndReached once for a given content length
|
|
this._sentEndForContentLength = this._scrollMetrics.contentLength;
|
|
onEndReached({distanceFromEnd});
|
|
} else if (distanceFromEnd > threshold) {
|
|
// If the user scrolls away from the end and back again cause
|
|
// an onEndReached to be triggered again
|
|
this._sentEndForContentLength = 0;
|
|
}
|
|
}
|
|
|
|
_onContentSizeChange = (width: number, height: number) => {
|
|
if (
|
|
width > 0 &&
|
|
height > 0 &&
|
|
this.props.initialScrollIndex != null &&
|
|
this.props.initialScrollIndex > 0 &&
|
|
!this._hasTriggeredInitialScrollToIndex
|
|
) {
|
|
if (this.props.contentOffset == null) {
|
|
this.scrollToIndex({
|
|
animated: false,
|
|
index: this.props.initialScrollIndex,
|
|
});
|
|
}
|
|
this._hasTriggeredInitialScrollToIndex = true;
|
|
}
|
|
if (this.props.onContentSizeChange) {
|
|
this.props.onContentSizeChange(width, height);
|
|
}
|
|
this._scrollMetrics.contentLength = this._selectLength({height, width});
|
|
this._scheduleCellsToRenderUpdate();
|
|
this._maybeCallOnEndReached();
|
|
};
|
|
|
|
/* Translates metrics from a scroll event in a parent VirtualizedList into
|
|
* coordinates relative to the child list.
|
|
*/
|
|
_convertParentScrollMetrics = (metrics: {
|
|
visibleLength: number,
|
|
offset: number,
|
|
...
|
|
}): $FlowFixMe => {
|
|
// Offset of the top of the nested list relative to the top of its parent's viewport
|
|
const offset = metrics.offset - this._offsetFromParentVirtualizedList;
|
|
// Child's visible length is the same as its parent's
|
|
const visibleLength = metrics.visibleLength;
|
|
const dOffset = offset - this._scrollMetrics.offset;
|
|
const contentLength = this._scrollMetrics.contentLength;
|
|
|
|
return {
|
|
visibleLength,
|
|
contentLength,
|
|
offset,
|
|
dOffset,
|
|
};
|
|
};
|
|
|
|
_onScroll = (e: Object) => {
|
|
this._nestedChildLists.forEach(childList => {
|
|
childList._onScroll(e);
|
|
});
|
|
if (this.props.onScroll) {
|
|
this.props.onScroll(e);
|
|
}
|
|
const timestamp = e.timeStamp;
|
|
let visibleLength = this._selectLength(e.nativeEvent.layoutMeasurement);
|
|
let contentLength = this._selectLength(e.nativeEvent.contentSize);
|
|
let offset = this._selectOffset(e.nativeEvent.contentOffset);
|
|
let dOffset = offset - this._scrollMetrics.offset;
|
|
|
|
if (this._isNestedWithSameOrientation()) {
|
|
if (this._scrollMetrics.contentLength === 0) {
|
|
// Ignore scroll events until onLayout has been called and we
|
|
// know our offset from our offset from our parent
|
|
return;
|
|
}
|
|
({visibleLength, contentLength, offset, dOffset} =
|
|
this._convertParentScrollMetrics({
|
|
visibleLength,
|
|
offset,
|
|
}));
|
|
}
|
|
|
|
const dt = this._scrollMetrics.timestamp
|
|
? Math.max(1, timestamp - this._scrollMetrics.timestamp)
|
|
: 1;
|
|
const velocity = dOffset / dt;
|
|
|
|
if (
|
|
dt > 500 &&
|
|
this._scrollMetrics.dt > 500 &&
|
|
contentLength > 5 * visibleLength &&
|
|
!this._hasWarned.perf
|
|
) {
|
|
infoLog(
|
|
'VirtualizedList: You have a large list that is slow to update - make sure your ' +
|
|
'renderItem function renders components that follow React performance best practices ' +
|
|
'like PureComponent, shouldComponentUpdate, etc.',
|
|
{dt, prevDt: this._scrollMetrics.dt, contentLength},
|
|
);
|
|
this._hasWarned.perf = true;
|
|
}
|
|
|
|
// For invalid negative values (w/ RTL), set this to 1.
|
|
const zoomScale = e.nativeEvent.zoomScale < 0 ? 1 : e.nativeEvent.zoomScale;
|
|
this._scrollMetrics = {
|
|
contentLength,
|
|
dt,
|
|
dOffset,
|
|
offset,
|
|
timestamp,
|
|
velocity,
|
|
visibleLength,
|
|
zoomScale,
|
|
};
|
|
this._updateViewableItems(this.props.data);
|
|
if (!this.props) {
|
|
return;
|
|
}
|
|
this._maybeCallOnEndReached();
|
|
if (velocity !== 0) {
|
|
this._fillRateHelper.activate();
|
|
}
|
|
this._computeBlankness();
|
|
this._scheduleCellsToRenderUpdate();
|
|
};
|
|
|
|
_scheduleCellsToRenderUpdate() {
|
|
const {first, last} = this.state;
|
|
const {offset, visibleLength, velocity} = this._scrollMetrics;
|
|
const itemCount = this.props.getItemCount(this.props.data);
|
|
let hiPri = false;
|
|
const onEndReachedThreshold = onEndReachedThresholdOrDefault(
|
|
this.props.onEndReachedThreshold,
|
|
);
|
|
const scrollingThreshold = (onEndReachedThreshold * visibleLength) / 2;
|
|
// Mark as high priority if we're close to the start of the first item
|
|
// But only if there are items before the first rendered item
|
|
if (first > 0) {
|
|
const distTop = offset - this.__getFrameMetricsApprox(first).offset;
|
|
hiPri =
|
|
hiPri || distTop < 0 || (velocity < -2 && distTop < scrollingThreshold);
|
|
}
|
|
// Mark as high priority if we're close to the end of the last item
|
|
// But only if there are items after the last rendered item
|
|
if (last < itemCount - 1) {
|
|
const distBottom =
|
|
this.__getFrameMetricsApprox(last).offset - (offset + visibleLength);
|
|
hiPri =
|
|
hiPri ||
|
|
distBottom < 0 ||
|
|
(velocity > 2 && distBottom < scrollingThreshold);
|
|
}
|
|
// Only trigger high-priority updates if we've actually rendered cells,
|
|
// and with that size estimate, accurately compute how many cells we should render.
|
|
// Otherwise, it would just render as many cells as it can (of zero dimension),
|
|
// each time through attempting to render more (limited by maxToRenderPerBatch),
|
|
// starving the renderer from actually laying out the objects and computing _averageCellLength.
|
|
// If this is triggered in an `componentDidUpdate` followed by a hiPri cellToRenderUpdate
|
|
// We shouldn't do another hipri cellToRenderUpdate
|
|
if (
|
|
hiPri &&
|
|
(this._averageCellLength || this.props.getItemLayout) &&
|
|
!this._hiPriInProgress
|
|
) {
|
|
this._hiPriInProgress = true;
|
|
// Don't worry about interactions when scrolling quickly; focus on filling content as fast
|
|
// as possible.
|
|
this._updateCellsToRenderBatcher.dispose({abort: true});
|
|
this._updateCellsToRender();
|
|
return;
|
|
} else {
|
|
this._updateCellsToRenderBatcher.schedule();
|
|
}
|
|
}
|
|
|
|
_onScrollBeginDrag = (e: ScrollEvent): void => {
|
|
this._nestedChildLists.forEach(childList => {
|
|
childList._onScrollBeginDrag(e);
|
|
});
|
|
this._viewabilityTuples.forEach(tuple => {
|
|
tuple.viewabilityHelper.recordInteraction();
|
|
});
|
|
this._hasInteracted = true;
|
|
this.props.onScrollBeginDrag && this.props.onScrollBeginDrag(e);
|
|
};
|
|
|
|
_onScrollEndDrag = (e: ScrollEvent): void => {
|
|
this._nestedChildLists.forEach(childList => {
|
|
childList._onScrollEndDrag(e);
|
|
});
|
|
const {velocity} = e.nativeEvent;
|
|
if (velocity) {
|
|
this._scrollMetrics.velocity = this._selectOffset(velocity);
|
|
}
|
|
this._computeBlankness();
|
|
this.props.onScrollEndDrag && this.props.onScrollEndDrag(e);
|
|
};
|
|
|
|
_onMomentumScrollBegin = (e: ScrollEvent): void => {
|
|
this._nestedChildLists.forEach(childList => {
|
|
childList._onMomentumScrollBegin(e);
|
|
});
|
|
this.props.onMomentumScrollBegin && this.props.onMomentumScrollBegin(e);
|
|
};
|
|
|
|
_onMomentumScrollEnd = (e: ScrollEvent): void => {
|
|
this._nestedChildLists.forEach(childList => {
|
|
childList._onMomentumScrollEnd(e);
|
|
});
|
|
this._scrollMetrics.velocity = 0;
|
|
this._computeBlankness();
|
|
this.props.onMomentumScrollEnd && this.props.onMomentumScrollEnd(e);
|
|
};
|
|
|
|
_updateCellsToRender = () => {
|
|
const {
|
|
data,
|
|
getItemCount,
|
|
onEndReachedThreshold: _onEndReachedThreshold,
|
|
} = this.props;
|
|
const onEndReachedThreshold = onEndReachedThresholdOrDefault(
|
|
_onEndReachedThreshold,
|
|
);
|
|
const isVirtualizationDisabled = this._isVirtualizationDisabled();
|
|
this._updateViewableItems(data);
|
|
if (!data) {
|
|
return;
|
|
}
|
|
this.setState(state => {
|
|
let newState: ?(
|
|
| {first: number, last: number, ...}
|
|
| $TEMPORARY$object<{first: number, last: number}>
|
|
);
|
|
const {contentLength, offset, visibleLength} = this._scrollMetrics;
|
|
const distanceFromEnd = contentLength - visibleLength - offset;
|
|
if (!isVirtualizationDisabled) {
|
|
// If we run this with bogus data, we'll force-render window {first: 0, last: 0},
|
|
// and wipe out the initialNumToRender rendered elements.
|
|
// So let's wait until the scroll view metrics have been set up. And until then,
|
|
// we will trust the initialNumToRender suggestion
|
|
if (visibleLength > 0 && contentLength > 0) {
|
|
// If we have a non-zero initialScrollIndex and run this before we've scrolled,
|
|
// we'll wipe out the initialNumToRender rendered elements starting at initialScrollIndex.
|
|
// So let's wait until we've scrolled the view to the right place. And until then,
|
|
// we will trust the initialScrollIndex suggestion.
|
|
|
|
// Thus, we want to recalculate the windowed render limits if any of the following hold:
|
|
// - initialScrollIndex is undefined or is 0
|
|
// - initialScrollIndex > 0 AND scrolling is complete
|
|
// - initialScrollIndex > 0 AND the end of the list is visible (this handles the case
|
|
// where the list is shorter than the visible area)
|
|
if (
|
|
!this.props.initialScrollIndex ||
|
|
this._scrollMetrics.offset ||
|
|
Math.abs(distanceFromEnd) < Number.EPSILON
|
|
) {
|
|
newState = computeWindowedRenderLimits(
|
|
this.props,
|
|
maxToRenderPerBatchOrDefault(this.props.maxToRenderPerBatch),
|
|
windowSizeOrDefault(this.props.windowSize),
|
|
state,
|
|
this.__getFrameMetricsApprox,
|
|
this._scrollMetrics,
|
|
);
|
|
}
|
|
}
|
|
} else {
|
|
const renderAhead =
|
|
distanceFromEnd < onEndReachedThreshold * visibleLength
|
|
? maxToRenderPerBatchOrDefault(this.props.maxToRenderPerBatch)
|
|
: 0;
|
|
newState = {
|
|
first: 0,
|
|
last: Math.min(state.last + renderAhead, getItemCount(data) - 1),
|
|
};
|
|
}
|
|
if (newState && this._nestedChildLists.size() > 0) {
|
|
const newFirst = newState.first;
|
|
const newLast = newState.last;
|
|
// If some cell in the new state has a child list in it, we should only render
|
|
// up through that item, so that we give that list a chance to render.
|
|
// Otherwise there's churn from multiple child lists mounting and un-mounting
|
|
// their items.
|
|
for (let ii = newFirst; ii <= newLast; ii++) {
|
|
const cellKeyForIndex = this._indicesToKeys.get(ii);
|
|
if (cellKeyForIndex == null) {
|
|
continue;
|
|
}
|
|
// For each cell, need to check whether any child list in it has more elements to render
|
|
|
|
const someChildHasMore = this._nestedChildLists.anyInCell(
|
|
cellKeyForIndex,
|
|
childList => childList.hasMore(),
|
|
);
|
|
|
|
if (someChildHasMore) {
|
|
newState.last = ii;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
if (
|
|
newState != null &&
|
|
newState.first === state.first &&
|
|
newState.last === state.last
|
|
) {
|
|
newState = null;
|
|
}
|
|
return newState;
|
|
});
|
|
};
|
|
|
|
// $FlowFixMe[missing-local-annot]
|
|
_createViewToken = (index: number, isViewable: boolean) => {
|
|
const {data, getItem} = this.props;
|
|
const item = getItem(data, index);
|
|
return {index, item, key: this._keyExtractor(item, index), isViewable};
|
|
};
|
|
|
|
__getFrameMetricsApprox: (
|
|
index: number,
|
|
props?: FrameMetricProps,
|
|
) => {
|
|
length: number,
|
|
offset: number,
|
|
...
|
|
} = index => {
|
|
const frame = this._getFrameMetrics(index);
|
|
if (frame && frame.index === index) {
|
|
// check for invalid frames due to row re-ordering
|
|
return frame;
|
|
} else {
|
|
const {getItemLayout} = this.props;
|
|
invariant(
|
|
!getItemLayout,
|
|
'Should not have to estimate frames when a measurement metrics function is provided',
|
|
);
|
|
return {
|
|
length: this._averageCellLength,
|
|
offset: this._averageCellLength * index,
|
|
};
|
|
}
|
|
};
|
|
|
|
_getFrameMetrics = (
|
|
index: number,
|
|
props?: FrameMetricProps,
|
|
): ?{
|
|
length: number,
|
|
offset: number,
|
|
index: number,
|
|
inLayout?: boolean,
|
|
...
|
|
} => {
|
|
const {data, getItem, getItemCount, getItemLayout} = this.props;
|
|
invariant(
|
|
getItemCount(data) > index,
|
|
'Tried to get frame for out of range index ' + index,
|
|
);
|
|
const item = getItem(data, index);
|
|
const frame = item && this._frames[this._keyExtractor(item, index)];
|
|
if (!frame || frame.index !== index) {
|
|
if (getItemLayout) {
|
|
/* $FlowFixMe[prop-missing] (>=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 getItemLayout(data, index);
|
|
}
|
|
}
|
|
return frame;
|
|
};
|
|
|
|
_updateViewableItems(data: any) {
|
|
this._viewabilityTuples.forEach(tuple => {
|
|
tuple.viewabilityHelper.onUpdate(
|
|
this.props,
|
|
this._scrollMetrics.offset,
|
|
this._scrollMetrics.visibleLength,
|
|
this._getFrameMetrics,
|
|
this._createViewToken,
|
|
tuple.onViewableItemsChanged,
|
|
this.state,
|
|
);
|
|
});
|
|
}
|
|
}
|
|
|
|
const styles = StyleSheet.create({
|
|
verticallyInverted: {
|
|
transform: [{scaleY: -1}],
|
|
},
|
|
horizontallyInverted: {
|
|
transform: [{scaleX: -1}],
|
|
},
|
|
debug: {
|
|
flex: 1,
|
|
},
|
|
debugOverlayBase: {
|
|
position: 'absolute',
|
|
top: 0,
|
|
right: 0,
|
|
},
|
|
debugOverlay: {
|
|
bottom: 0,
|
|
width: 20,
|
|
borderColor: 'blue',
|
|
borderWidth: 1,
|
|
},
|
|
debugOverlayFrame: {
|
|
left: 0,
|
|
backgroundColor: 'orange',
|
|
},
|
|
debugOverlayFrameLast: {
|
|
left: 0,
|
|
borderColor: 'green',
|
|
borderWidth: 2,
|
|
},
|
|
debugOverlayFrameVis: {
|
|
left: 0,
|
|
borderColor: 'red',
|
|
borderWidth: 2,
|
|
},
|
|
});
|
|
|
|
module.exports = (VirtualizedListInjection.getOrDefault(
|
|
VirtualizedList,
|
|
): typeof VirtualizedList);
|