734 lines
28 KiB
JavaScript
734 lines
28 KiB
JavaScript
/**
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* Copyright (c) 2013-present, Facebook, Inc.
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* All rights reserved.
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*
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* This source code is licensed under the BSD-style license found in the
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* LICENSE file in the root directory of this source tree. An additional grant
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* of patent rights can be found in the PATENTS file in the same directory.
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*
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* Facebook, Inc. ("Facebook") owns all right, title and interest, including
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* all intellectual property and other proprietary rights, in and to the React
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* Native CustomComponents software (the "Software"). Subject to your
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* compliance with these terms, you are hereby granted a non-exclusive,
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* worldwide, royalty-free copyright license to (1) use and copy the Software;
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* and (2) reproduce and distribute the Software as part of your own software
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* ("Your Software"). Facebook reserves all rights not expressly granted to
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* you in this license agreement.
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*
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* THE SOFTWARE AND DOCUMENTATION, IF ANY, ARE PROVIDED "AS IS" AND ANY EXPRESS
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* OR IMPLIED WARRANTIES (INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE) ARE DISCLAIMED.
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* IN NO EVENT SHALL FACEBOOK OR ITS AFFILIATES, OFFICERS, DIRECTORS OR
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* EMPLOYEES BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
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* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
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* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
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* OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
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* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
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* OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THE SOFTWARE, EVEN IF
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* ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*
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* @providesModule WindowedListView
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* @flow
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*/
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'use strict';
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const IncrementalGroup = require('IncrementalGroup');
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const React = require('React');
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const ScrollView = require('ScrollView');
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const Set = require('Set');
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const StyleSheet = require('StyleSheet');
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const Systrace = require('Systrace');
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const View = require('View');
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const ViewabilityHelper = require('ViewabilityHelper');
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const clamp = require('clamp');
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const deepDiffer = require('deepDiffer');
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const infoLog = require('infoLog');
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const invariant = require('invariant');
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const nullthrows = require('nullthrows');
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import type ReactComponent from 'ReactComponent';
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const DEBUG = false;
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/**
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* An experimental ListView implementation designed for efficient memory usage
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* when rendering huge/infinite lists. It works by rendering a subset of rows
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* and replacing offscreen rows with an empty spacer, which means that it has to
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* re-render rows when scrolling back up.
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*
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* Note that rows must be the same height when they are re-mounted as when they
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* are unmounted otherwise the content will jump around. This means that any
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* state that affects the height, such as tap to expand, should be stored
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* outside the row component to maintain continuity.
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*
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* This is not a drop-in replacement for `ListView` - many features are not
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* supported, including section headers, dataSources, horizontal layout, etc.
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*
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* Row data should be provided as a simple array corresponding to rows. `===`
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* is used to determine if a row has changed and should be re-rendered.
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*
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* Rendering is done incrementally one row at a time to minimize the amount of
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* work done per JS event tick. Individual rows can also use <Incremental>
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* to further break up the work and keep the app responsive and improve scroll
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* perf if rows get exceedingly complex.
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*
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* Note that it's possible to scroll faster than rows can be rendered. Instead
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* of showing the user a bunch of un-mounted blank space, WLV sets contentInset
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* to prevent scrolling into unrendered areas. Supply the
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* `renderWindowBoundaryIndicator` prop to indicate the boundary to the user,
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* e.g. with a row placeholder.
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*/
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type Props = {
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/**
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* A simple array of data blobs that are passed to the renderRow function in
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* order. Note there is no dataSource like in the standard `ListView`.
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*/
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data: Array<{rowKey: string, rowData: any}>;
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/**
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* Takes a data blob from the `data` array prop plus some meta info and should
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* return a row.
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*/
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renderRow: (
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rowData: any, sectionIdx: number, rowIdx: number, rowKey: string
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) => ?ReactElement;
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/**
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* Rendered when the list is scrolled faster than rows can be rendered.
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*/
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renderWindowBoundaryIndicator?: () => ?ReactElement;
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/**
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* Always rendered at the bottom of all the rows.
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*/
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renderFooter?: () => ?ReactElement;
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/**
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* Pipes through normal onScroll events from the underlying `ScrollView`.
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*/
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onScroll?: (event: Object) => void;
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/**
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* Called when the rows that are visible in the viewport change.
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*/
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onVisibleRowsChanged?: (firstIdx: number, count: number) => void;
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/**
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* Called when the viewability of rows changes, as defined by the
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* `viewablePercentThreshold` prop.
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*/
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onViewableRowsChanged?: (viewableRows: Array<number>) => void;
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/**
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* The percent of a row that must be visible to consider it "viewable".
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*/
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viewablePercentThreshold: number;
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/**
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* Number of rows to render on first mount.
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*/
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initialNumToRender: number;
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/**
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* Maximum number of rows to render while scrolling, i.e. the window size.
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*/
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maxNumToRender: number;
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/**
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* Number of rows to render beyond the viewport. Note that this combined with
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* `maxNumToRender` and the number of rows that can fit in one screen will
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* determine how many rows to render above the viewport.
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*/
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numToRenderAhead: number;
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/**
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* Used to log perf events for async row rendering.
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*/
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asyncRowPerfEventName?: string;
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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: (props: ?Object) => ReactElement;
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/**
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* Use to disable incremental rendering when not wanted, e.g. to speed up initial render.
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*/
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disableIncrementalRendering: boolean;
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/**
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* This determines how frequently events such as scroll and layout can trigger a re-render.
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*/
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recomputeRowsBatchingPeriod: number;
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/**
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* Called when rows will be mounted/unmounted. Mounted rows always form a contiguous block so it is expressed as a
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* range of start plus count.
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*/
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onMountedRowsWillChange?: (firstIdx: number, count: number) => void;
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/**
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* Change this when you want to make sure the WindowedListView will re-render, for example when the result of
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* `renderScrollComponent` might change. It will be compared in `shouldComponentUpdate`.
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*/
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shouldUpdateToken?: string;
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};
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type State = {
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boundaryIndicatorHeight?: number;
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firstRow: number;
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lastRow: number;
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};
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class WindowedListView extends React.Component {
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props: Props;
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state: State;
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_firstVisible: number = -1;
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_lastVisible: number = -1;
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_scrollOffsetY: number = 0;
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_isScrolling: boolean = false;
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_frameHeight: number = 0;
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_rowFrames: {[key: string]: Object} = {};
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_rowRenderMode: {[key: string]: null | 'async' | 'sync'} = {};
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_rowFramesDirty: boolean = false;
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_hasCalledOnEndReached: boolean = false;
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_willComputeRowsToRender: boolean = false;
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_timeoutHandle: number = 0;
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_incrementPending: boolean = false;
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_viewableRows: Array<number> = [];
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_cellsInProgress: Set<string> = new Set();
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_scrollRef: ?Object;
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static defaultProps = {
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initialNumToRender: 10,
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maxNumToRender: 30,
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numToRenderAhead: 10,
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viewablePercentThreshold: 50,
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renderScrollComponent: (props) => <ScrollView {...props} />,
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disableIncrementalRendering: false,
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recomputeRowsBatchingPeriod: 10, // This should capture most events that will happen in one frame
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};
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constructor(props: Props) {
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super(props);
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invariant(
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this.props.numToRenderAhead < this.props.maxNumToRender,
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'WindowedListView: numToRenderAhead must be less than maxNumToRender'
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);
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this.state = {
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firstRow: 0,
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lastRow: Math.min(this.props.data.length, this.props.initialNumToRender) - 1,
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};
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}
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getScrollResponder(): ?ReactComponent {
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return this._scrollRef &&
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this._scrollRef.getScrollResponder &&
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this._scrollRef.getScrollResponder();
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}
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shouldComponentUpdate(newProps: Props, newState: State): boolean {
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if (newState !== this.state) {
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return true;
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}
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for (const key in newProps) {
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if (key !== 'data' && newProps[key] !== this.props[key]) {
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return true;
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}
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}
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const newDataSubset = newProps.data.slice(newState.firstRow, newState.lastRow + 1);
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const prevDataSubset = this.props.data.slice(this.state.firstRow, this.state.lastRow + 1);
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if (newDataSubset.length !== prevDataSubset.length) {
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return true;
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}
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for (let idx = 0; idx < newDataSubset.length; idx++) {
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if (newDataSubset[idx] !== prevDataSubset[idx]) {
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return true;
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}
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}
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return false;
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}
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componentWillReceiveProps(newProps: Object) {
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// This has to happen immediately otherwise we could crash, e.g. if the data
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// array has gotten shorter.
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this._computeRowsToRender(newProps);
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}
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_onMomentumScrollEnd = (e: Object) => {
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this._onScroll(e);
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};
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_onScroll = (e: Object) => {
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const newScrollY = e.nativeEvent.contentOffset.y;
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this._isScrolling = this._scrollOffsetY !== newScrollY;
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this._scrollOffsetY = newScrollY;
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this._frameHeight = e.nativeEvent.layoutMeasurement.height;
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// We don't want to enqueue any updates if any cells are in the middle of an incremental render,
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// because it would just be wasted work.
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if (this._cellsInProgress.size === 0) {
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this._enqueueComputeRowsToRender();
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}
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if (this.props.onViewableRowsChanged && Object.keys(this._rowFrames).length) {
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const viewableRows = ViewabilityHelper.computeViewableRows(
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this.props.viewablePercentThreshold,
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this._rowFrames,
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this.props.data,
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e.nativeEvent.contentOffset.y,
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e.nativeEvent.layoutMeasurement.height
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);
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if (deepDiffer(viewableRows, this._viewableRows)) {
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this._viewableRows = viewableRows;
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nullthrows(this.props.onViewableRowsChanged)(this._viewableRows);
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}
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}
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this.props.onScroll && this.props.onScroll(e);
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};
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// Caller does the diffing so we don't have to.
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_onNewLayout = (params: {rowKey: string, layout: Object}) => {
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const {rowKey, layout} = params;
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if (DEBUG) {
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const layoutPrev = this._rowFrames[rowKey] || {};
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infoLog(
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'record layout for row: ',
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{k: rowKey, h: layout.height, y: layout.y, x: layout.x, hp: layoutPrev.height, yp: layoutPrev.y}
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);
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}
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if (this._rowFrames[rowKey]) {
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const deltaY = Math.abs(this._rowFrames[rowKey].y - layout.y);
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const deltaH = Math.abs(this._rowFrames[rowKey].height - layout.height);
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if (deltaY > 2 || deltaH > 2) {
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const dataEntry = this.props.data.find((datum) => datum.rowKey === rowKey);
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console.warn('layout jump: ', {dataEntry, prevLayout: this._rowFrames[rowKey], newLayout: layout});
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}
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}
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this._rowFrames[rowKey] = {...layout, offscreenLayoutDone: true};
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this._rowFramesDirty = true;
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if (this._cellsInProgress.size === 0) {
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this._enqueueComputeRowsToRender();
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}
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};
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_onWillUnmountCell = (rowKey: string) => {
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if (this._rowFrames[rowKey]) {
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this._rowFrames[rowKey].offscreenLayoutDone = false;
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this._rowRenderMode[rowKey] = null;
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}
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};
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/**
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* This is used to keep track of cells that are in the process of rendering. If any cells are in progress, then
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* other updates are skipped because they will just be wasted work.
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*/
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_onProgressChange = ({rowKey, inProgress}: {rowKey: string, inProgress: boolean}) => {
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if (inProgress) {
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this._cellsInProgress.add(rowKey);
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} else {
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this._cellsInProgress.delete(rowKey);
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}
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};
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/**
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* Recomputing which rows to render is batched up and run asynchronously to avoid wastful updates, e.g. from multiple
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* layout updates in rapid succession.
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*/
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_enqueueComputeRowsToRender(): void {
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if (!this._willComputeRowsToRender) {
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this._willComputeRowsToRender = true; // batch up computations
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clearTimeout(this._timeoutHandle);
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this._timeoutHandle = setTimeout(
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() => {
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this._willComputeRowsToRender = false;
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this._incrementPending = false;
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this._computeRowsToRender(this.props);
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},
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this.props.recomputeRowsBatchingPeriod
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);
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}
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}
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componentWillUnmount() {
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clearTimeout(this._timeoutHandle);
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}
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_computeRowsToRender(props: Object): void {
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const totalRows = props.data.length;
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if (totalRows === 0) {
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this._updateVisibleRows(-1, -1);
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this.setState({
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firstRow: 0,
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lastRow: -1,
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});
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return;
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}
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const rowFrames = this._rowFrames;
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let firstVisible = -1;
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let lastVisible = 0;
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let lastRow = this.state.lastRow;
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const top = this._scrollOffsetY;
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const bottom = top + this._frameHeight;
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for (let idx = 0; idx < lastRow; idx++) {
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const frame = rowFrames[props.data[idx].rowKey];
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if (!frame) {
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// No frame - sometimes happens when they come out of order, so just wait for the rest.
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return;
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}
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if (((frame.y + frame.height) > top) && (firstVisible < 0)) {
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firstVisible = idx;
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}
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if (frame.y < bottom) {
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lastVisible = idx;
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} else {
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break;
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}
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}
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if (firstVisible === -1) {
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firstVisible = 0;
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}
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this._updateVisibleRows(firstVisible, lastVisible);
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// Unfortuantely, we can't use <Incremental> to simplify our increment logic in this function because we need to
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// make sure that cells are rendered in the right order one at a time when scrolling back up.
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const numRendered = lastRow - this.state.firstRow + 1;
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// Our last row target that we will approach incrementally
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const targetLastRow = clamp(
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numRendered - 1, // Don't reduce numRendered when scrolling back up
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lastVisible + props.numToRenderAhead, // Primary goal
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totalRows - 1, // Don't render past the end
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);
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// Increment the last row one at a time per JS event loop
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if (!this._incrementPending) {
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if (targetLastRow > this.state.lastRow) {
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lastRow++;
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this._incrementPending = true;
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} else if (targetLastRow < this.state.lastRow) {
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lastRow--;
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this._incrementPending = true;
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}
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}
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// Once last row is set, figure out the first row
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const firstRow = Math.max(
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0, // Don't render past the top
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lastRow - props.maxNumToRender + 1, // Don't exceed max to render
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lastRow - numRendered, // Don't render more than 1 additional row
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);
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if (lastRow >= totalRows) {
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// It's possible that the number of rows decreased by more than one
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// increment could compensate for. Need to make sure we don't render more
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// than one new row at a time, but don't want to render past the end of
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// the data.
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lastRow = totalRows - 1;
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}
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if (props.onEndReached) {
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// Make sure we call onEndReached exactly once every time we reach the
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// end. Resets if scoll back up and down again.
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const willBeAtTheEnd = lastRow === (totalRows - 1);
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if (willBeAtTheEnd && !this._hasCalledOnEndReached) {
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props.onEndReached();
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this._hasCalledOnEndReached = true;
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} else {
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// If lastRow is changing, reset so we can call onEndReached again
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this._hasCalledOnEndReached = this.state.lastRow === lastRow;
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}
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}
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const rowsShouldChange = firstRow !== this.state.firstRow || lastRow !== this.state.lastRow;
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if (this._rowFramesDirty || rowsShouldChange) {
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if (rowsShouldChange) {
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props.onMountedRowsWillChange && props.onMountedRowsWillChange(firstRow, lastRow - firstRow + 1);
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infoLog(
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'WLV: row render range will change:',
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{firstRow, firstVis: this._firstVisible, lastVis: this._lastVisible, lastRow},
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);
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}
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this._rowFramesDirty = false;
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this.setState({firstRow, lastRow});
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}
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}
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_updateVisibleRows(newFirstVisible: number, newLastVisible: number) {
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if (this.props.onVisibleRowsChanged) {
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if (this._firstVisible !== newFirstVisible ||
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this._lastVisible !== newLastVisible) {
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this.props.onVisibleRowsChanged(newFirstVisible, newLastVisible - newFirstVisible + 1);
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}
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}
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this._firstVisible = newFirstVisible;
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this._lastVisible = newLastVisible;
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}
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render(): ReactElement {
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const {firstRow, lastRow} = this.state;
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const rowFrames = this._rowFrames;
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const rows = [];
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let spacerHeight = 0;
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// Incremental rendering is a tradeoff between throughput and responsiveness. When we have plenty of buffer (say 50%
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// of the target), we render incrementally to keep the app responsive. If we are dangerously low on buffer (say
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// below 25%) we always disable incremental to try to catch up as fast as possible. In the middle, we only disable
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// incremental while scrolling since it's unlikely the user will try to press a button while scrolling. We also
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// ignore the "buffer" size when we are bumped up against the edge of the available data.
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const firstBuffer = firstRow === 0 ? Infinity : this._firstVisible - firstRow;
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const lastBuffer = lastRow === this.props.data.length - 1 ? Infinity : lastRow - this._lastVisible;
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const minBuffer = Math.min(firstBuffer, lastBuffer);
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const disableIncrementalRendering = this.props.disableIncrementalRendering ||
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(this._isScrolling && minBuffer < this.props.numToRenderAhead * 0.5) ||
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(minBuffer < this.props.numToRenderAhead * 0.25);
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// Render mode is sticky while the component is mounted.
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for (let ii = firstRow; ii <= lastRow; ii++) {
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const rowKey = this.props.data[ii].rowKey;
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if (this._rowRenderMode[rowKey] === 'sync' || (disableIncrementalRendering && this._rowRenderMode[rowKey] !== 'async')) {
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this._rowRenderMode[rowKey] = 'sync';
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} else {
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this._rowRenderMode[rowKey] = 'async';
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}
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}
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for (let ii = firstRow; ii <= lastRow; ii++) {
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const rowKey = this.props.data[ii].rowKey;
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if (!rowFrames[rowKey]) {
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break; // if rowFrame missing, no following ones will exist so quit early
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}
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// Look for the first row where offscreen layout is done (only true for mounted rows) or it will be rendered
|
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// synchronously and set the spacer height such that it will offset all the unmounted rows before that one using
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// the saved frame data.
|
|
if (rowFrames[rowKey].offscreenLayoutDone || this._rowRenderMode[rowKey] === 'sync') {
|
|
if (ii > 0) {
|
|
const prevRowKey = this.props.data[ii - 1].rowKey;
|
|
const frame = rowFrames[prevRowKey];
|
|
spacerHeight = frame ? frame.y + frame.height : 0;
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
let showIndicator = false;
|
|
if (spacerHeight > (this.state.boundaryIndicatorHeight || 0) && this.props.renderWindowBoundaryIndicator) {
|
|
showIndicator = true;
|
|
spacerHeight -= this.state.boundaryIndicatorHeight || 0;
|
|
}
|
|
DEBUG && infoLog('render top spacer with height ', spacerHeight);
|
|
rows.push(<View key="sp-top" style={{height: spacerHeight}} />);
|
|
if (this.props.renderWindowBoundaryIndicator) {
|
|
// Always render it, even if removed, so that we can get the height right away and don't waste time creating/
|
|
// destroying it. Should see if there is a better spinner option that is not as expensive.
|
|
rows.push(
|
|
<View
|
|
style={!showIndicator && styles.remove}
|
|
key="ind-top"
|
|
onLayout={(e) => {
|
|
const layout = e.nativeEvent.layout;
|
|
if (layout.height !== this.state.boundaryIndicatorHeight) {
|
|
this.setState({boundaryIndicatorHeight: layout.height});
|
|
}
|
|
}}>
|
|
{this.props.renderWindowBoundaryIndicator()}
|
|
</View>
|
|
);
|
|
}
|
|
for (let idx = firstRow; idx <= lastRow; idx++) {
|
|
const rowKey = this.props.data[idx].rowKey;
|
|
const includeInLayout = this._rowRenderMode[rowKey] === 'sync' ||
|
|
(this._rowFrames[rowKey] && this._rowFrames[rowKey].offscreenLayoutDone);
|
|
rows.push(
|
|
<CellRenderer
|
|
key={rowKey}
|
|
rowKey={rowKey}
|
|
rowIndex={idx}
|
|
onNewLayout={this._onNewLayout}
|
|
onWillUnmount={this._onWillUnmountCell}
|
|
includeInLayout={includeInLayout}
|
|
onProgressChange={this._onProgressChange}
|
|
asyncRowPerfEventName={this.props.asyncRowPerfEventName}
|
|
rowData={this.props.data[idx].rowData}
|
|
renderRow={this.props.renderRow}
|
|
/>
|
|
);
|
|
}
|
|
const lastRowKey = this.props.data[lastRow].rowKey;
|
|
const showFooter = this._rowFrames[lastRowKey] &&
|
|
this._rowFrames[lastRowKey].offscreenLayoutDone &&
|
|
lastRow === this.props.data.length - 1;
|
|
if (this.props.renderFooter) {
|
|
rows.push(
|
|
<View
|
|
key="ind-footer"
|
|
style={showFooter ? styles.include : styles.remove}>
|
|
{this.props.renderFooter()}
|
|
</View>
|
|
);
|
|
}
|
|
if (this.props.renderWindowBoundaryIndicator) {
|
|
rows.push(
|
|
<View
|
|
key="ind-bot"
|
|
style={showFooter ? styles.remove : styles.include}
|
|
onLayout={(e) => {
|
|
const layout = e.nativeEvent.layout;
|
|
if (layout.height !== this.state.boundaryIndicatorHeight) {
|
|
this.setState({boundaryIndicatorHeight: layout.height});
|
|
}
|
|
}}>
|
|
{this.props.renderWindowBoundaryIndicator()}
|
|
</View>
|
|
);
|
|
}
|
|
// Prevent user from scrolling into empty space of unmounted rows.
|
|
const contentInset = {top: firstRow === 0 ? 0 : -spacerHeight};
|
|
return (
|
|
this.props.renderScrollComponent({
|
|
scrollEventThrottle: 50,
|
|
removeClippedSubviews: true,
|
|
...this.props,
|
|
contentInset,
|
|
ref: (ref) => { this._scrollRef = ref; },
|
|
onScroll: this._onScroll,
|
|
onMomentumScrollEnd: this._onMomentumScrollEnd,
|
|
children: rows,
|
|
})
|
|
);
|
|
}
|
|
}
|
|
|
|
// performance testing id, unique for each component mount cycle
|
|
let g_perf_update_id = 0;
|
|
|
|
type CellProps = {
|
|
/**
|
|
* Row-specific data passed to renderRow and used in shouldComponentUpdate with ===
|
|
*/
|
|
rowData: mixed;
|
|
rowKey: string;
|
|
/**
|
|
* Renders the actual row contents.
|
|
*/
|
|
renderRow: (
|
|
rowData: mixed, sectionIdx: number, rowIdx: number, rowKey: string
|
|
) => ?ReactElement;
|
|
/**
|
|
* Index of the row, passed through to other callbacks.
|
|
*/
|
|
rowIndex: number;
|
|
/**
|
|
* Used for marking async begin/end events for row rendering.
|
|
*/
|
|
asyncRowPerfEventName: ?string;
|
|
/**
|
|
* Initially false to indicate the cell should be rendered "offscreen" with position: absolute so that incremental
|
|
* rendering doesn't cause things to jump around. Once onNewLayout is called after offscreen rendering has completed,
|
|
* includeInLayout will be set true and the finished cell can be dropped into place.
|
|
*
|
|
* This is coordinated outside this component so the parent can syncronize this re-render with managing the
|
|
* placeholder sizing.
|
|
*/
|
|
includeInLayout: boolean;
|
|
/**
|
|
* Updates the parent with the latest layout. Only called when incremental rendering is done and triggers the parent
|
|
* to re-render this row with includeInLayout true.
|
|
*/
|
|
onNewLayout: (params: {rowKey: string, layout: Object}) => void;
|
|
/**
|
|
* Used to track when rendering is in progress so the parent can avoid wastedful re-renders that are just going to be
|
|
* invalidated once the cell finishes.
|
|
*/
|
|
onProgressChange: (progress: {rowKey: string; inProgress: boolean}) => void;
|
|
/**
|
|
* Used to invalidate the layout so the parent knows it needs to compensate for the height in the placeholder size.
|
|
*/
|
|
onWillUnmount: (rowKey: string) => void;
|
|
};
|
|
class CellRenderer extends React.Component {
|
|
props: CellProps;
|
|
_containerRef: View;
|
|
_offscreenRenderDone = false;
|
|
_timeout = 0;
|
|
_lastLayout: ?Object = null;
|
|
_perfUpdateID: number = 0;
|
|
_asyncCookie: any;
|
|
_includeInLayoutLatch: boolean = false;
|
|
componentWillMount() {
|
|
if (this.props.asyncRowPerfEventName) {
|
|
this._perfUpdateID = g_perf_update_id++;
|
|
this._asyncCookie = Systrace.beginAsyncEvent(this.props.asyncRowPerfEventName + this._perfUpdateID);
|
|
infoLog(`perf_asynctest_${this.props.asyncRowPerfEventName}_start ${this._perfUpdateID} ${Date.now()}`);
|
|
}
|
|
if (this.props.includeInLayout) {
|
|
this._includeInLayoutLatch = true;
|
|
}
|
|
this.props.onProgressChange({rowKey: this.props.rowKey, inProgress: true});
|
|
}
|
|
_onLayout = (e) => {
|
|
const layout = e.nativeEvent.layout;
|
|
const layoutChanged = deepDiffer(this._lastLayout, layout);
|
|
this._lastLayout = layout;
|
|
if (!this._offscreenRenderDone || !layoutChanged) {
|
|
return; // Don't send premature or duplicate updates
|
|
}
|
|
this.props.onNewLayout({
|
|
rowKey: this.props.rowKey,
|
|
layout,
|
|
});
|
|
};
|
|
_updateParent() {
|
|
invariant(!this._offscreenRenderDone, 'should only finish rendering once');
|
|
this._offscreenRenderDone = true;
|
|
|
|
// If this is not called before calling onNewLayout, the number of inProgress cells will remain non-zero,
|
|
// and thus the onNewLayout call will not fire the needed state change update.
|
|
this.props.onProgressChange({rowKey: this.props.rowKey, inProgress: false});
|
|
|
|
// If an onLayout event hasn't come in yet, then we skip here and assume it will come in later. This happens
|
|
// when Incremental is disabled and _onOffscreenRenderDone is called faster than layout can happen.
|
|
this._lastLayout && this.props.onNewLayout({rowKey: this.props.rowKey, layout: this._lastLayout});
|
|
|
|
DEBUG && infoLog('\n >>>>> display row ' + this.props.rowIndex + '\n\n\n');
|
|
if (this.props.asyncRowPerfEventName) {
|
|
// Note this doesn't include the native render time but is more accurate than also including the JS render
|
|
// time of anything that has been queued up.
|
|
Systrace.endAsyncEvent(this.props.asyncRowPerfEventName + this._perfUpdateID, this._asyncCookie);
|
|
infoLog(`perf_asynctest_${this.props.asyncRowPerfEventName}_end ${this._perfUpdateID} ${Date.now()}`);
|
|
}
|
|
}
|
|
_onOffscreenRenderDone = () => {
|
|
DEBUG && infoLog('_onOffscreenRenderDone for row ' + this.props.rowIndex);
|
|
if (this._includeInLayoutLatch) {
|
|
this._updateParent(); // rendered straight into layout, so no need to flush
|
|
} else {
|
|
this._timeout = setTimeout(() => this._updateParent(), 1); // Flush any pending layout events.
|
|
}
|
|
};
|
|
componentWillUnmount() {
|
|
clearTimeout(this._timeout);
|
|
this.props.onProgressChange({rowKey: this.props.rowKey, inProgress: false});
|
|
this.props.onWillUnmount(this.props.rowKey);
|
|
}
|
|
componentWillReceiveProps(newProps) {
|
|
if (newProps.includeInLayout && !this.props.includeInLayout) {
|
|
invariant(this._offscreenRenderDone, 'Should never try to add to layout before render done');
|
|
this._includeInLayoutLatch = true; // Once we render in layout, make sure it sticks.
|
|
this._containerRef.setNativeProps({style: styles.include});
|
|
}
|
|
}
|
|
shouldComponentUpdate(newProps: CellProps) {
|
|
return newProps.rowData !== this.props.rowData;
|
|
}
|
|
_setRef = (ref) => {
|
|
this._containerRef = ref;
|
|
};
|
|
render() {
|
|
let debug;
|
|
if (DEBUG) {
|
|
infoLog('render cell ' + this.props.rowIndex);
|
|
const Text = require('Text');
|
|
debug = <Text style={{backgroundColor: 'lightblue'}}>
|
|
Row: {this.props.rowIndex}
|
|
</Text>;
|
|
}
|
|
const style = this._includeInLayoutLatch ? styles.include : styles.remove;
|
|
return (
|
|
<IncrementalGroup
|
|
disabled={this._includeInLayoutLatch}
|
|
onDone={this._onOffscreenRenderDone}
|
|
name={`WLVCell_${this.props.rowIndex}`}>
|
|
<View
|
|
ref={this._setRef}
|
|
style={style}
|
|
onLayout={this._onLayout}>
|
|
{debug}
|
|
{this.props.renderRow(this.props.rowData, 0, this.props.rowIndex, this.props.rowKey)}
|
|
{debug}
|
|
</View>
|
|
</IncrementalGroup>
|
|
);
|
|
}
|
|
}
|
|
|
|
const removedXOffset = DEBUG ? 123 : 0;
|
|
|
|
const styles = StyleSheet.create({
|
|
include: {
|
|
position: 'relative',
|
|
left: 0,
|
|
right: 0,
|
|
opacity: 1,
|
|
},
|
|
remove: {
|
|
position: 'absolute',
|
|
left: removedXOffset,
|
|
right: -removedXOffset,
|
|
opacity: DEBUG ? 0.1 : 0,
|
|
},
|
|
});
|
|
|
|
module.exports = WindowedListView;
|