767 lines
26 KiB
JavaScript
767 lines
26 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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* @providesModule ListView
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* @flow
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* @format
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*/
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'use strict';
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var ListViewDataSource = require('ListViewDataSource');
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var Platform = require('Platform');
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var React = require('React');
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var PropTypes = require('prop-types');
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var ReactNative = require('ReactNative');
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var RCTScrollViewManager = require('NativeModules').ScrollViewManager;
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var ScrollView = require('ScrollView');
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var ScrollResponder = require('ScrollResponder');
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var StaticRenderer = require('StaticRenderer');
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/* $FlowFixMe(>=0.54.0 site=react_native_oss) This comment suppresses an error
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* found when Flow v0.54 was deployed. To see the error delete this comment and
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* run Flow. */
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var TimerMixin = require('react-timer-mixin');
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var View = require('View');
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/* $FlowFixMe(>=0.54.0 site=react_native_oss) This comment suppresses an error
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* found when Flow v0.54 was deployed. To see the error delete this comment and
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* run Flow. */
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var cloneReferencedElement = require('react-clone-referenced-element');
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var createReactClass = require('create-react-class');
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var isEmpty = require('isEmpty');
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var merge = require('merge');
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var DEFAULT_PAGE_SIZE = 1;
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var DEFAULT_INITIAL_ROWS = 10;
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var DEFAULT_SCROLL_RENDER_AHEAD = 1000;
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var DEFAULT_END_REACHED_THRESHOLD = 1000;
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var DEFAULT_SCROLL_CALLBACK_THROTTLE = 50;
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/**
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* DEPRECATED - use one of the new list components, such as [`FlatList`](docs/flatlist.html)
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* or [`SectionList`](docs/sectionlist.html) for bounded memory use, fewer bugs,
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* better performance, an easier to use API, and more features. Check out this
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* [blog post](https://facebook.github.io/react-native/blog/2017/03/13/better-list-views.html)
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* for more details.
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*
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* ListView - A core component designed for efficient display of vertically
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* scrolling lists of changing data. The minimal API is to create a
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* [`ListView.DataSource`](docs/listviewdatasource.html), populate it with a simple
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* array of data blobs, and instantiate a `ListView` component with that data
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* source and a `renderRow` callback which takes a blob from the data array and
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* returns a renderable component.
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*
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* Minimal example:
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*
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* ```
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* class MyComponent extends Component {
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* constructor() {
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* super();
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* const ds = new ListView.DataSource({rowHasChanged: (r1, r2) => r1 !== r2});
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* this.state = {
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* dataSource: ds.cloneWithRows(['row 1', 'row 2']),
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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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* <ListView
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* dataSource={this.state.dataSource}
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* renderRow={(rowData) => <Text>{rowData}</Text>}
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* />
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* );
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* }
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* }
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* ```
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*
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* ListView also supports more advanced features, including sections with sticky
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* section headers, header and footer support, callbacks on reaching the end of
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* the available data (`onEndReached`) and on the set of rows that are visible
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* in the device viewport change (`onChangeVisibleRows`), and several
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* performance optimizations.
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*
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* There are a few performance operations designed to make ListView scroll
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* smoothly while dynamically loading potentially very large (or conceptually
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* infinite) data sets:
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*
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* * Only re-render changed rows - the rowHasChanged function provided to the
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* data source tells the ListView if it needs to re-render a row because the
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* source data has changed - see ListViewDataSource for more details.
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*
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* * Rate-limited row rendering - By default, only one row is rendered per
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* event-loop (customizable with the `pageSize` prop). This breaks up the
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* work into smaller chunks to reduce the chance of dropping frames while
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* rendering rows.
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*/
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var ListView = createReactClass({
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displayName: 'ListView',
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_childFrames: ([]: Array<Object>),
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_sentEndForContentLength: (null: ?number),
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_scrollComponent: (null: any),
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_prevRenderedRowsCount: 0,
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_visibleRows: ({}: Object),
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scrollProperties: ({}: Object),
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mixins: [ScrollResponder.Mixin, TimerMixin],
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statics: {
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DataSource: ListViewDataSource,
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},
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/**
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* You must provide a renderRow function. If you omit any of the other render
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* functions, ListView will simply skip rendering them.
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*
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* - renderRow(rowData, sectionID, rowID, highlightRow);
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* - renderSectionHeader(sectionData, sectionID);
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*/
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propTypes: {
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...ScrollView.propTypes,
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/**
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* An instance of [ListView.DataSource](docs/listviewdatasource.html) to use
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*/
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dataSource: PropTypes.instanceOf(ListViewDataSource).isRequired,
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/**
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* (sectionID, rowID, adjacentRowHighlighted) => renderable
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*
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* If provided, a renderable component to be rendered as the separator
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* below each row but not the last row if there is a section header below.
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* Take a sectionID and rowID of the row above and whether its adjacent row
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* is highlighted.
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*/
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renderSeparator: PropTypes.func,
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/**
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* (rowData, sectionID, rowID, highlightRow) => renderable
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*
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* Takes a data entry from the data source and its ids and should return
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* a renderable component to be rendered as the row. By default the data
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* is exactly what was put into the data source, but it's also possible to
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* provide custom extractors. ListView can be notified when a row is
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* being highlighted by calling `highlightRow(sectionID, rowID)`. This
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* sets a boolean value of adjacentRowHighlighted in renderSeparator, allowing you
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* to control the separators above and below the highlighted row. The highlighted
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* state of a row can be reset by calling highlightRow(null).
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*/
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renderRow: PropTypes.func.isRequired,
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/**
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* How many rows to render on initial component mount. Use this to make
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* it so that the first screen worth of data appears at one time instead of
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* over the course of multiple frames.
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*/
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initialListSize: PropTypes.number.isRequired,
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/**
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* Called when all rows have been rendered and the list has been scrolled
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* to within onEndReachedThreshold of the bottom. The native scroll
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* event is provided.
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*/
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onEndReached: PropTypes.func,
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/**
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* Threshold in pixels (virtual, not physical) for calling onEndReached.
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*/
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onEndReachedThreshold: PropTypes.number.isRequired,
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/**
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* Number of rows to render per event loop. Note: if your 'rows' are actually
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* cells, i.e. they don't span the full width of your view (as in the
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* ListViewGridLayoutExample), you should set the pageSize to be a multiple
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* of the number of cells per row, otherwise you're likely to see gaps at
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* the edge of the ListView as new pages are loaded.
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*/
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pageSize: PropTypes.number.isRequired,
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/**
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* () => renderable
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*
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* The header and footer are always rendered (if these props are provided)
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* on every render pass. If they are expensive to re-render, wrap them
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* in StaticContainer or other mechanism as appropriate. Footer is always
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* at the bottom of the list, and header at the top, on every render pass.
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* In a horizontal ListView, the header is rendered on the left and the
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* footer on the right.
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*/
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renderFooter: PropTypes.func,
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renderHeader: PropTypes.func,
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/**
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* (sectionData, sectionID) => renderable
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*
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* If provided, a header is rendered for this section.
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*/
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renderSectionHeader: PropTypes.func,
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/**
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* (props) => renderable
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*
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* A function that returns the scrollable component in which the list rows
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* are rendered. Defaults to returning a ScrollView with the given props.
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*/
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renderScrollComponent: PropTypes.func.isRequired,
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/**
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* How early to start rendering rows before they come on screen, in
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* pixels.
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*/
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scrollRenderAheadDistance: PropTypes.number.isRequired,
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/**
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* (visibleRows, changedRows) => void
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*
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* Called when the set of visible rows changes. `visibleRows` maps
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* { sectionID: { rowID: true }} for all the visible rows, and
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* `changedRows` maps { sectionID: { rowID: true | false }} for the rows
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* that have changed their visibility, with true indicating visible, and
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* false indicating the view has moved out of view.
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*/
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onChangeVisibleRows: PropTypes.func,
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/**
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* A performance optimization for improving scroll perf of
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* large lists, used in conjunction with overflow: 'hidden' on the row
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* containers. This is enabled by default.
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*/
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removeClippedSubviews: PropTypes.bool,
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/**
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* Makes the sections headers sticky. The sticky behavior means that it
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* will scroll with the content at the top of the section until it reaches
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* the top of the screen, at which point it will stick to the top until it
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* is pushed off the screen by the next section header. This property is
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* not supported in conjunction with `horizontal={true}`. Only enabled by
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* default on iOS because of typical platform standards.
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*/
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stickySectionHeadersEnabled: PropTypes.bool,
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/**
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* An array of child indices determining which children get docked to the
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* top of the screen when scrolling. For example, passing
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* `stickyHeaderIndices={[0]}` will cause the first child to be fixed to the
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* top of the scroll view. This property is not supported in conjunction
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* with `horizontal={true}`.
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*/
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stickyHeaderIndices: PropTypes.arrayOf(PropTypes.number).isRequired,
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/**
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* Flag indicating whether empty section headers should be rendered. In the future release
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* empty section headers will be rendered by default, and the flag will be deprecated.
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* If empty sections are not desired to be rendered their indices should be excluded from sectionID object.
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*/
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enableEmptySections: PropTypes.bool,
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},
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/**
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* Exports some data, e.g. for perf investigations or analytics.
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*/
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getMetrics: function() {
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return {
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contentLength: this.scrollProperties.contentLength,
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totalRows: this.props.enableEmptySections
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? this.props.dataSource.getRowAndSectionCount()
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: this.props.dataSource.getRowCount(),
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renderedRows: this.state.curRenderedRowsCount,
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visibleRows: Object.keys(this._visibleRows).length,
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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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* Note that `this._scrollComponent` 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: function() {
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if (this._scrollComponent && this._scrollComponent.getScrollResponder) {
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return this._scrollComponent.getScrollResponder();
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}
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},
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getScrollableNode: function() {
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if (this._scrollComponent && this._scrollComponent.getScrollableNode) {
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return this._scrollComponent.getScrollableNode();
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} else {
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return ReactNative.findNodeHandle(this._scrollComponent);
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}
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},
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/**
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* Scrolls to a given x, y offset, either immediately or with a smooth animation.
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*
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* See `ScrollView#scrollTo`.
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*/
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scrollTo: function(...args: Array<mixed>) {
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if (this._scrollComponent && this._scrollComponent.scrollTo) {
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this._scrollComponent.scrollTo(...args);
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}
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},
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/**
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* If this is a vertical ListView scrolls to the bottom.
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* If this is a horizontal ListView scrolls to the right.
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*
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* Use `scrollToEnd({animated: true})` for smooth animated scrolling,
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* `scrollToEnd({animated: false})` for immediate scrolling.
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* If no options are passed, `animated` defaults to true.
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*
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* See `ScrollView#scrollToEnd`.
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*/
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scrollToEnd: function(options?: ?{animated?: ?boolean}) {
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if (this._scrollComponent) {
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if (this._scrollComponent.scrollToEnd) {
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this._scrollComponent.scrollToEnd(options);
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} else {
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console.warn(
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'The scroll component used by the ListView does not support ' +
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'scrollToEnd. Check the renderScrollComponent prop of your ListView.',
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);
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}
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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: function() {
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if (this._scrollComponent && this._scrollComponent.flashScrollIndicators) {
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this._scrollComponent.flashScrollIndicators();
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}
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},
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setNativeProps: function(props: Object) {
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if (this._scrollComponent) {
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this._scrollComponent.setNativeProps(props);
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}
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},
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/**
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* React life cycle hooks.
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*/
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getDefaultProps: function() {
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return {
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initialListSize: DEFAULT_INITIAL_ROWS,
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pageSize: DEFAULT_PAGE_SIZE,
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renderScrollComponent: props => <ScrollView {...props} />,
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scrollRenderAheadDistance: DEFAULT_SCROLL_RENDER_AHEAD,
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onEndReachedThreshold: DEFAULT_END_REACHED_THRESHOLD,
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stickySectionHeadersEnabled: Platform.OS === 'ios',
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stickyHeaderIndices: [],
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};
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},
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getInitialState: function() {
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return {
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curRenderedRowsCount: this.props.initialListSize,
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highlightedRow: ({}: Object),
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};
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},
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getInnerViewNode: function() {
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return this._scrollComponent.getInnerViewNode();
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},
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UNSAFE_componentWillMount: function() {
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// this data should never trigger a render pass, so don't put in state
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this.scrollProperties = {
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visibleLength: null,
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contentLength: null,
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offset: 0,
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};
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this._childFrames = [];
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this._visibleRows = {};
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this._prevRenderedRowsCount = 0;
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this._sentEndForContentLength = null;
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},
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componentDidMount: function() {
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// do this in animation frame until componentDidMount actually runs after
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// the component is laid out
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this.requestAnimationFrame(() => {
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this._measureAndUpdateScrollProps();
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});
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},
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UNSAFE_componentWillReceiveProps: function(nextProps: Object) {
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if (
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this.props.dataSource !== nextProps.dataSource ||
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this.props.initialListSize !== nextProps.initialListSize
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) {
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this.setState(
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(state, props) => {
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this._prevRenderedRowsCount = 0;
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return {
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curRenderedRowsCount: Math.min(
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Math.max(state.curRenderedRowsCount, props.initialListSize),
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props.enableEmptySections
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? props.dataSource.getRowAndSectionCount()
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: props.dataSource.getRowCount(),
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),
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};
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},
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() => this._renderMoreRowsIfNeeded(),
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);
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}
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},
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componentDidUpdate: function() {
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this.requestAnimationFrame(() => {
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this._measureAndUpdateScrollProps();
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});
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},
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_onRowHighlighted: function(sectionID: string, rowID: string) {
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this.setState({highlightedRow: {sectionID, rowID}});
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},
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render: function() {
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var bodyComponents = [];
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var dataSource = this.props.dataSource;
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var allRowIDs = dataSource.rowIdentities;
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var rowCount = 0;
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var stickySectionHeaderIndices = [];
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const {renderSectionHeader} = this.props;
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var header = this.props.renderHeader && this.props.renderHeader();
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var footer = this.props.renderFooter && this.props.renderFooter();
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var totalIndex = header ? 1 : 0;
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for (var sectionIdx = 0; sectionIdx < allRowIDs.length; sectionIdx++) {
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var sectionID = dataSource.sectionIdentities[sectionIdx];
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var rowIDs = allRowIDs[sectionIdx];
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if (rowIDs.length === 0) {
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if (this.props.enableEmptySections === undefined) {
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/* $FlowFixMe(>=0.54.0 site=react_native_oss) This comment suppresses
|
|
* an error found when Flow v0.54 was deployed. To see the error
|
|
* delete this comment and run Flow. */
|
|
var warning = require('fbjs/lib/warning');
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warning(
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false,
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'In next release empty section headers will be rendered.' +
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" In this release you can use 'enableEmptySections' flag to render empty section headers.",
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);
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continue;
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} else {
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var invariant = require('fbjs/lib/invariant');
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invariant(
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this.props.enableEmptySections,
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"In next release 'enableEmptySections' flag will be deprecated, empty section headers will always be rendered." +
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' If empty section headers are not desirable their indices should be excluded from sectionIDs object.' +
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" In this release 'enableEmptySections' may only have value 'true' to allow empty section headers rendering.",
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);
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}
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}
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if (renderSectionHeader) {
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const element = renderSectionHeader(
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dataSource.getSectionHeaderData(sectionIdx),
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sectionID,
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);
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if (element) {
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bodyComponents.push(
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React.cloneElement(element, {key: 's_' + sectionID}),
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);
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if (this.props.stickySectionHeadersEnabled) {
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stickySectionHeaderIndices.push(totalIndex);
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}
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totalIndex++;
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}
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}
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for (var rowIdx = 0; rowIdx < rowIDs.length; rowIdx++) {
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var rowID = rowIDs[rowIdx];
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var comboID = sectionID + '_' + rowID;
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var shouldUpdateRow =
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rowCount >= this._prevRenderedRowsCount &&
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dataSource.rowShouldUpdate(sectionIdx, rowIdx);
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var row = (
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<StaticRenderer
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key={'r_' + comboID}
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shouldUpdate={!!shouldUpdateRow}
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render={this.props.renderRow.bind(
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null,
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dataSource.getRowData(sectionIdx, rowIdx),
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sectionID,
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rowID,
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this._onRowHighlighted,
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)}
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/>
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);
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bodyComponents.push(row);
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totalIndex++;
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if (
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this.props.renderSeparator &&
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(rowIdx !== rowIDs.length - 1 || sectionIdx === allRowIDs.length - 1)
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) {
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var adjacentRowHighlighted =
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this.state.highlightedRow.sectionID === sectionID &&
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(this.state.highlightedRow.rowID === rowID ||
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this.state.highlightedRow.rowID === rowIDs[rowIdx + 1]);
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var separator = this.props.renderSeparator(
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sectionID,
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rowID,
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adjacentRowHighlighted,
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);
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if (separator) {
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bodyComponents.push(<View key={'s_' + comboID}>{separator}</View>);
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totalIndex++;
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}
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}
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if (++rowCount === this.state.curRenderedRowsCount) {
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break;
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}
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}
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if (rowCount >= this.state.curRenderedRowsCount) {
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break;
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}
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}
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|
|
var {renderScrollComponent, ...props} = this.props;
|
|
if (!props.scrollEventThrottle) {
|
|
props.scrollEventThrottle = DEFAULT_SCROLL_CALLBACK_THROTTLE;
|
|
}
|
|
if (props.removeClippedSubviews === undefined) {
|
|
props.removeClippedSubviews = true;
|
|
}
|
|
Object.assign(props, {
|
|
onScroll: this._onScroll,
|
|
stickyHeaderIndices: this.props.stickyHeaderIndices.concat(
|
|
stickySectionHeaderIndices,
|
|
),
|
|
|
|
// Do not pass these events downstream to ScrollView since they will be
|
|
// registered in ListView's own ScrollResponder.Mixin
|
|
onKeyboardWillShow: undefined,
|
|
onKeyboardWillHide: undefined,
|
|
onKeyboardDidShow: undefined,
|
|
onKeyboardDidHide: undefined,
|
|
});
|
|
|
|
return cloneReferencedElement(
|
|
renderScrollComponent(props),
|
|
{
|
|
ref: this._setScrollComponentRef,
|
|
onContentSizeChange: this._onContentSizeChange,
|
|
onLayout: this._onLayout,
|
|
DEPRECATED_sendUpdatedChildFrames:
|
|
typeof props.onChangeVisibleRows !== undefined,
|
|
},
|
|
header,
|
|
bodyComponents,
|
|
footer,
|
|
);
|
|
},
|
|
|
|
/**
|
|
* Private methods
|
|
*/
|
|
|
|
_measureAndUpdateScrollProps: function() {
|
|
var scrollComponent = this.getScrollResponder();
|
|
if (!scrollComponent || !scrollComponent.getInnerViewNode) {
|
|
return;
|
|
}
|
|
|
|
// RCTScrollViewManager.calculateChildFrames is not available on
|
|
// every platform
|
|
RCTScrollViewManager &&
|
|
RCTScrollViewManager.calculateChildFrames &&
|
|
RCTScrollViewManager.calculateChildFrames(
|
|
ReactNative.findNodeHandle(scrollComponent),
|
|
this._updateVisibleRows,
|
|
);
|
|
},
|
|
|
|
_setScrollComponentRef: function(scrollComponent: Object) {
|
|
this._scrollComponent = scrollComponent;
|
|
},
|
|
|
|
_onContentSizeChange: function(width: number, height: number) {
|
|
var contentLength = !this.props.horizontal ? height : width;
|
|
if (contentLength !== this.scrollProperties.contentLength) {
|
|
this.scrollProperties.contentLength = contentLength;
|
|
this._updateVisibleRows();
|
|
this._renderMoreRowsIfNeeded();
|
|
}
|
|
this.props.onContentSizeChange &&
|
|
this.props.onContentSizeChange(width, height);
|
|
},
|
|
|
|
_onLayout: function(event: Object) {
|
|
var {width, height} = event.nativeEvent.layout;
|
|
var visibleLength = !this.props.horizontal ? height : width;
|
|
if (visibleLength !== this.scrollProperties.visibleLength) {
|
|
this.scrollProperties.visibleLength = visibleLength;
|
|
this._updateVisibleRows();
|
|
this._renderMoreRowsIfNeeded();
|
|
}
|
|
this.props.onLayout && this.props.onLayout(event);
|
|
},
|
|
|
|
_maybeCallOnEndReached: function(event?: Object) {
|
|
if (
|
|
this.props.onEndReached &&
|
|
this.scrollProperties.contentLength !== this._sentEndForContentLength &&
|
|
this._getDistanceFromEnd(this.scrollProperties) <
|
|
this.props.onEndReachedThreshold &&
|
|
this.state.curRenderedRowsCount ===
|
|
(this.props.enableEmptySections
|
|
? this.props.dataSource.getRowAndSectionCount()
|
|
: this.props.dataSource.getRowCount())
|
|
) {
|
|
this._sentEndForContentLength = this.scrollProperties.contentLength;
|
|
this.props.onEndReached(event);
|
|
return true;
|
|
}
|
|
return false;
|
|
},
|
|
|
|
_renderMoreRowsIfNeeded: function() {
|
|
if (
|
|
this.scrollProperties.contentLength === null ||
|
|
this.scrollProperties.visibleLength === null ||
|
|
this.state.curRenderedRowsCount ===
|
|
(this.props.enableEmptySections
|
|
? this.props.dataSource.getRowAndSectionCount()
|
|
: this.props.dataSource.getRowCount())
|
|
) {
|
|
this._maybeCallOnEndReached();
|
|
return;
|
|
}
|
|
|
|
var distanceFromEnd = this._getDistanceFromEnd(this.scrollProperties);
|
|
if (distanceFromEnd < this.props.scrollRenderAheadDistance) {
|
|
this._pageInNewRows();
|
|
}
|
|
},
|
|
|
|
_pageInNewRows: function() {
|
|
this.setState(
|
|
(state, props) => {
|
|
var rowsToRender = Math.min(
|
|
state.curRenderedRowsCount + props.pageSize,
|
|
props.enableEmptySections
|
|
? props.dataSource.getRowAndSectionCount()
|
|
: props.dataSource.getRowCount(),
|
|
);
|
|
this._prevRenderedRowsCount = state.curRenderedRowsCount;
|
|
return {
|
|
curRenderedRowsCount: rowsToRender,
|
|
};
|
|
},
|
|
() => {
|
|
this._measureAndUpdateScrollProps();
|
|
this._prevRenderedRowsCount = this.state.curRenderedRowsCount;
|
|
},
|
|
);
|
|
},
|
|
|
|
_getDistanceFromEnd: function(scrollProperties: Object) {
|
|
return (
|
|
scrollProperties.contentLength -
|
|
scrollProperties.visibleLength -
|
|
scrollProperties.offset
|
|
);
|
|
},
|
|
|
|
_updateVisibleRows: function(updatedFrames?: Array<Object>) {
|
|
if (!this.props.onChangeVisibleRows) {
|
|
return; // No need to compute visible rows if there is no callback
|
|
}
|
|
if (updatedFrames) {
|
|
updatedFrames.forEach(newFrame => {
|
|
this._childFrames[newFrame.index] = merge(newFrame);
|
|
});
|
|
}
|
|
var isVertical = !this.props.horizontal;
|
|
var dataSource = this.props.dataSource;
|
|
var visibleMin = this.scrollProperties.offset;
|
|
var visibleMax = visibleMin + this.scrollProperties.visibleLength;
|
|
var allRowIDs = dataSource.rowIdentities;
|
|
|
|
var header = this.props.renderHeader && this.props.renderHeader();
|
|
var totalIndex = header ? 1 : 0;
|
|
var visibilityChanged = false;
|
|
var changedRows = {};
|
|
for (var sectionIdx = 0; sectionIdx < allRowIDs.length; sectionIdx++) {
|
|
var rowIDs = allRowIDs[sectionIdx];
|
|
if (rowIDs.length === 0) {
|
|
continue;
|
|
}
|
|
var sectionID = dataSource.sectionIdentities[sectionIdx];
|
|
if (this.props.renderSectionHeader) {
|
|
totalIndex++;
|
|
}
|
|
var visibleSection = this._visibleRows[sectionID];
|
|
if (!visibleSection) {
|
|
visibleSection = {};
|
|
}
|
|
for (var rowIdx = 0; rowIdx < rowIDs.length; rowIdx++) {
|
|
var rowID = rowIDs[rowIdx];
|
|
var frame = this._childFrames[totalIndex];
|
|
totalIndex++;
|
|
if (
|
|
this.props.renderSeparator &&
|
|
(rowIdx !== rowIDs.length - 1 || sectionIdx === allRowIDs.length - 1)
|
|
) {
|
|
totalIndex++;
|
|
}
|
|
if (!frame) {
|
|
break;
|
|
}
|
|
var rowVisible = visibleSection[rowID];
|
|
var min = isVertical ? frame.y : frame.x;
|
|
var max = min + (isVertical ? frame.height : frame.width);
|
|
if ((!min && !max) || min === max) {
|
|
break;
|
|
}
|
|
if (min > visibleMax || max < visibleMin) {
|
|
if (rowVisible) {
|
|
visibilityChanged = true;
|
|
delete visibleSection[rowID];
|
|
if (!changedRows[sectionID]) {
|
|
changedRows[sectionID] = {};
|
|
}
|
|
changedRows[sectionID][rowID] = false;
|
|
}
|
|
} else if (!rowVisible) {
|
|
visibilityChanged = true;
|
|
visibleSection[rowID] = true;
|
|
if (!changedRows[sectionID]) {
|
|
changedRows[sectionID] = {};
|
|
}
|
|
changedRows[sectionID][rowID] = true;
|
|
}
|
|
}
|
|
if (!isEmpty(visibleSection)) {
|
|
this._visibleRows[sectionID] = visibleSection;
|
|
} else if (this._visibleRows[sectionID]) {
|
|
delete this._visibleRows[sectionID];
|
|
}
|
|
}
|
|
visibilityChanged &&
|
|
this.props.onChangeVisibleRows(this._visibleRows, changedRows);
|
|
},
|
|
|
|
_onScroll: function(e: Object) {
|
|
var isVertical = !this.props.horizontal;
|
|
this.scrollProperties.visibleLength =
|
|
e.nativeEvent.layoutMeasurement[isVertical ? 'height' : 'width'];
|
|
this.scrollProperties.contentLength =
|
|
e.nativeEvent.contentSize[isVertical ? 'height' : 'width'];
|
|
this.scrollProperties.offset =
|
|
e.nativeEvent.contentOffset[isVertical ? 'y' : 'x'];
|
|
this._updateVisibleRows(e.nativeEvent.updatedChildFrames);
|
|
if (!this._maybeCallOnEndReached(e)) {
|
|
this._renderMoreRowsIfNeeded();
|
|
}
|
|
|
|
if (
|
|
this.props.onEndReached &&
|
|
this._getDistanceFromEnd(this.scrollProperties) >
|
|
this.props.onEndReachedThreshold
|
|
) {
|
|
// Scrolled out of the end zone, so it should be able to trigger again.
|
|
this._sentEndForContentLength = null;
|
|
}
|
|
|
|
this.props.onScroll && this.props.onScroll(e);
|
|
},
|
|
});
|
|
|
|
module.exports = ListView;
|