react-native/Libraries/CustomComponents/ListView/ListView.js

497 lines
16 KiB
JavaScript

/**
* Copyright (c) 2015, Facebook, Inc. All rights reserved.
*
* Facebook, Inc. (“Facebook”) owns all right, title and interest, including
* all intellectual property and other proprietary rights, in and to the React
* Native CustomComponents software (the “Software”). Subject to your
* compliance with these terms, you are hereby granted a non-exclusive,
* worldwide, royalty-free copyright license to (1) use and copy the Software;
* and (2) reproduce and distribute the Software as part of your own software
* (“Your Software”). Facebook reserves all rights not expressly granted to
* you in this license agreement.
*
* THE SOFTWARE AND DOCUMENTATION, IF ANY, ARE PROVIDED "AS IS" AND ANY EXPRESS
* OR IMPLIED WARRANTIES (INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE) ARE DISCLAIMED.
* IN NO EVENT SHALL FACEBOOK OR ITS AFFILIATES, OFFICERS, DIRECTORS OR
* EMPLOYEES BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
* OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
* OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THE SOFTWARE, EVEN IF
* ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* @providesModule ListView
*/
'use strict';
var ListViewDataSource = require('ListViewDataSource');
var React = require('React');
var RCTUIManager = require('NativeModules').UIManager;
var ScrollView = require('ScrollView');
var ScrollResponder = require('ScrollResponder');
var StaticRenderer = require('StaticRenderer');
var TimerMixin = require('react-timer-mixin');
var logError = require('logError');
var merge = require('merge');
var isEmpty = require('isEmpty');
var PropTypes = React.PropTypes;
var DEFAULT_PAGE_SIZE = 1;
var DEFAULT_INITIAL_ROWS = 10;
var DEFAULT_SCROLL_RENDER_AHEAD = 1000;
var DEFAULT_END_REACHED_THRESHOLD = 1000;
var DEFAULT_SCROLL_CALLBACK_THROTTLE = 50;
var RENDER_INTERVAL = 20;
var SCROLLVIEW_REF = 'listviewscroll';
/**
* ListView - A core component designed for efficient display of vertically
* scrolling lists of changing data. The minimal API is to create a
* `ListView.DataSource`, populate it with a simple array of data blobs, and
* instantiate a `ListView` component with that data source and a `renderRow`
* callback which takes a blob from the data array and returns a renderable
* component.
*
* Minimal example:
*
* ```
* getInitialState: function() {
* var ds = new ListView.DataSource({rowHasChanged: (r1, r2) => r1 !== r2});
* return {
* dataSource: ds.cloneWithRows(['row 1', 'row 2']),
* };
* },
*
* render: function() {
* return (
* <ListView
* dataSource={this.state.dataSource}
* renderRow={(rowData) => <Text>{rowData}</Text>}
* />
* );
* },
* ```
*
* ListView also supports more advanced features, including sections with sticky
* section headers, header and footer support, callbacks on reaching the end of
* the available data (`onEndReached`) and on the set of rows that are visible
* in the device viewport change (`onChangeVisibleRows`), and several
* performance optimizations.
*
* There are a few performance operations designed to make ListView scroll
* smoothly while dynamically loading potentially very large (or conceptually
* infinite) data sets:
*
* * Only re-render changed rows - the hasRowChanged function provided to the
* data source tells the ListView if it needs to re-render a row because the
* source data has changed - see ListViewDataSource for more details.
*
* * Rate-limited row rendering - By default, only one row is rendered per
* event-loop (customizable with the `pageSize` prop). This breaks up the
* work into smaller chunks to reduce the chance of dropping frames while
* rendering rows.
*/
var ListView = React.createClass({
mixins: [ScrollResponder.Mixin, TimerMixin],
statics: {
DataSource: ListViewDataSource,
},
/**
* You must provide a renderRow function. If you omit any of the other render
* functions, ListView will simply skip rendering them.
*
* - renderRow(rowData, sectionID, rowID);
* - renderSectionHeader(sectionData, sectionID);
*/
propTypes: {
...ScrollView.propTypes,
dataSource: PropTypes.instanceOf(ListViewDataSource).isRequired,
/**
* (rowData, sectionID, rowID) => renderable
* Takes a data entry from the data source and its ids and should return
* a renderable component to be rendered as the row. By default the data
* is exactly what was put into the data source, but it's also possible to
* provide custom extractors.
*/
renderRow: PropTypes.func.isRequired,
/**
* How many rows to render on initial component mount. Use this to make
* it so that the first screen worth of data apears at one time instead of
* over the course of multiple frames.
*/
initialListSize: PropTypes.number,
/**
* Called when all rows have been rendered and the list has been scrolled
* to within onEndReachedThreshold of the bottom. The native scroll
* event is provided.
*/
onEndReached: PropTypes.func,
/**
* Threshold in pixels for onEndReached.
*/
onEndReachedThreshold: PropTypes.number,
/**
* Number of rows to render per event loop.
*/
pageSize: PropTypes.number,
/**
* () => renderable
*
* The header and footer are always rendered (if these props are provided)
* on every render pass. If they are expensive to re-render, wrap them
* in StaticContainer or other mechanism as appropriate. Footer is always
* at the bottom of the list, and header at the top, on every render pass.
*/
renderFooter: PropTypes.func,
renderHeader: PropTypes.func,
/**
* (sectionData, sectionID) => renderable
*
* If provided, a sticky header is rendered for this section. The sticky
* behavior means that it will scroll with the content at the top of the
* section until it reaches the top of the screen, at which point it will
* stick to the top until it is pushed off the screen by the next section
* header.
*/
renderSectionHeader: PropTypes.func,
/**
* How early to start rendering rows before they come on screen, in
* pixels.
*/
scrollRenderAheadDistance: React.PropTypes.number,
/**
* (visibleRows, changedRows) => void
*
* Called when the set of visible rows changes. `visibleRows` maps
* { sectionID: { rowID: true }} for all the visible rows, and
* `changedRows` maps { sectionID: { rowID: true | false }} for the rows
* that have changed their visibility, with true indicating visible, and
* false indicating the view has moved out of view.
*/
onChangeVisibleRows: React.PropTypes.func,
/**
* An experimental performance optimization for improving scroll perf of
* large lists, used in conjunction with overflow: 'hidden' on the row
* containers. Use at your own risk.
*/
removeClippedSubviews: React.PropTypes.bool,
},
/**
* Exports some data, e.g. for perf investigations or analytics.
*/
getMetrics: function() {
return {
contentHeight: this.scrollProperties.contentHeight,
totalRows: this.props.dataSource.getRowCount(),
renderedRows: this.state.curRenderedRowsCount,
visibleRows: Object.keys(this._visibleRows).length,
};
},
/**
* Provides a handle to the underlying scroll responder to support operations
* such as scrollTo.
*/
getScrollResponder: function() {
return this.refs[SCROLLVIEW_REF];
},
setNativeProps: function(props) {
this.refs[SCROLLVIEW_REF].setNativeProps(props);
},
/**
* React life cycle hooks.
*/
getDefaultProps: function() {
return {
initialListSize: DEFAULT_INITIAL_ROWS,
pageSize: DEFAULT_PAGE_SIZE,
scrollRenderAheadDistance: DEFAULT_SCROLL_RENDER_AHEAD,
onEndReachedThreshold: DEFAULT_END_REACHED_THRESHOLD,
};
},
getInitialState: function() {
return {
curRenderedRowsCount: this.props.initialListSize,
prevRenderedRowsCount: 0,
};
},
componentWillMount: function() {
// this data should never trigger a render pass, so don't put in state
this.scrollProperties = {
visibleHeight: null,
contentHeight: null,
offsetY: 0
};
this._childFrames = [];
this._visibleRows = {};
},
componentDidMount: function() {
// do this in animation frame until componentDidMount actually runs after
// the component is laid out
this.requestAnimationFrame(() => {
this._measureAndUpdateScrollProps();
this.setInterval(this._renderMoreRowsIfNeeded, RENDER_INTERVAL);
});
},
componentWillReceiveProps: function(nextProps) {
if (this.props.dataSource !== nextProps.dataSource) {
this.setState({prevRenderedRowsCount: 0});
}
},
render: function() {
var bodyComponents = [];
var dataSource = this.props.dataSource;
var allRowIDs = dataSource.rowIdentities;
var rowCount = 0;
var sectionHeaderIndices = [];
var header = this.props.renderHeader && this.props.renderHeader();
var footer = this.props.renderFooter && this.props.renderFooter();
var totalIndex = header ? 1 : 0;
for (var sectionIdx = 0; sectionIdx < allRowIDs.length; sectionIdx++) {
var sectionID = dataSource.sectionIdentities[sectionIdx];
var rowIDs = allRowIDs[sectionIdx];
if (rowIDs.length === 0) {
continue;
}
if (this.props.renderSectionHeader) {
var shouldUpdateHeader = rowCount >= this.state.prevRenderedRowsCount &&
dataSource.sectionHeaderShouldUpdate(sectionIdx);
bodyComponents.push(
<StaticRenderer
key={'s_' + sectionID}
shouldUpdate={!!shouldUpdateHeader}
render={this.props.renderSectionHeader.bind(
null,
dataSource.getSectionHeaderData(sectionIdx),
sectionID
)}
/>
);
sectionHeaderIndices.push(totalIndex++);
}
for (var rowIdx = 0; rowIdx < rowIDs.length; rowIdx++) {
var rowID = rowIDs[rowIdx];
var comboID = sectionID + rowID;
var shouldUpdateRow = rowCount >= this.state.prevRenderedRowsCount &&
dataSource.rowShouldUpdate(sectionIdx, rowIdx);
var row =
<StaticRenderer
key={'r_' + comboID}
shouldUpdate={!!shouldUpdateRow}
render={this.props.renderRow.bind(
null,
dataSource.getRowData(sectionIdx, rowIdx),
sectionID,
rowID
)}
/>;
bodyComponents.push(row);
totalIndex++;
if (++rowCount === this.state.curRenderedRowsCount) {
break;
}
}
if (rowCount >= this.state.curRenderedRowsCount) {
break;
}
}
var props = merge(
this.props, {
onScroll: this._onScroll,
stickyHeaderIndices: sectionHeaderIndices,
}
);
if (!props.scrollEventThrottle) {
props.scrollEventThrottle = DEFAULT_SCROLL_CALLBACK_THROTTLE;
}
return (
<ScrollView {...props}
ref={SCROLLVIEW_REF}>
{header}
{bodyComponents}
{footer}
</ScrollView>
);
},
/**
* Private methods
*/
_measureAndUpdateScrollProps: function() {
RCTUIManager.measureLayout(
this.refs[SCROLLVIEW_REF].getInnerViewNode(),
React.findNodeHandle(this.refs[SCROLLVIEW_REF]),
logError,
this._setScrollContentHeight
);
RCTUIManager.measureLayoutRelativeToParent(
React.findNodeHandle(this.refs[SCROLLVIEW_REF]),
logError,
this._setScrollVisibleHeight
);
},
_setScrollContentHeight: function(left, top, width, height) {
this.scrollProperties.contentHeight = height;
},
_setScrollVisibleHeight: function(left, top, width, height) {
this.scrollProperties.visibleHeight = height;
this._updateVisibleRows();
},
_renderMoreRowsIfNeeded: function() {
if (this.scrollProperties.contentHeight === null ||
this.scrollProperties.visibleHeight === null ||
this.state.curRenderedRowsCount === this.props.dataSource.getRowCount()) {
return;
}
var distanceFromEnd = this._getDistanceFromEnd(this.scrollProperties);
if (distanceFromEnd < this.props.scrollRenderAheadDistance) {
this._pageInNewRows();
}
},
_pageInNewRows: function() {
var rowsToRender = Math.min(
this.state.curRenderedRowsCount + this.props.pageSize,
this.props.dataSource.getRowCount()
);
this.setState(
{
prevRenderedRowsCount: this.state.curRenderedRowsCount,
curRenderedRowsCount: rowsToRender
},
() => {
this._measureAndUpdateScrollProps();
this.setState({
prevRenderedRowsCount: this.state.curRenderedRowsCount,
});
}
);
},
_getDistanceFromEnd: function(scrollProperties) {
return scrollProperties.contentHeight -
scrollProperties.visibleHeight -
scrollProperties.offsetY;
},
_updateVisibleRows: function(e) {
if (!this.props.onChangeVisibleRows) {
return; // No need to compute visible rows if there is no callback
}
var updatedFrames = e && e.nativeEvent.updatedChildFrames;
if (updatedFrames) {
updatedFrames.forEach((frame) => {
this._childFrames[frame.index] = merge(frame);
});
}
var dataSource = this.props.dataSource;
var visibleTop = this.scrollProperties.offsetY;
var visibleBottom = visibleTop + this.scrollProperties.visibleHeight;
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 (!frame) {
break;
}
var rowVisible = visibleSection[rowID];
var top = frame.y;
var bottom = top + frame.height;
if (top > visibleBottom || bottom < visibleTop) {
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) {
this.scrollProperties.visibleHeight = e.nativeEvent.layoutMeasurement.height;
this.scrollProperties.contentHeight = e.nativeEvent.contentSize.height;
this.scrollProperties.offsetY = e.nativeEvent.contentOffset.y;
this._updateVisibleRows(e);
var nearEnd = this._getDistanceFromEnd(this.scrollProperties) < this.props.onEndReachedThreshold;
if (nearEnd &&
this.props.onEndReached &&
this.scrollProperties.contentHeight !== this._sentEndForContentHeight &&
this.state.curRenderedRowsCount === this.props.dataSource.getRowCount()) {
this._sentEndForContentHeight = this.scrollProperties.contentHeight;
this.props.onEndReached(e);
} else {
this._renderMoreRowsIfNeeded();
}
this.props.onScroll && this.props.onScroll(e);
},
});
module.exports = ListView;