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

656 lines
24 KiB
JavaScript

/**
* Copyright (c) 2013-present, Facebook, Inc.
* All rights reserved.
*
* This source code is licensed under the BSD-style license found in the
* LICENSE file in the root directory of this source tree. An additional grant
* of patent rights can be found in the PATENTS file in the same directory.
*
* 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 ReactNative = require('ReactNative');
var RCTScrollViewManager = require('NativeModules').ScrollViewManager;
var ScrollView = require('ScrollView');
var ScrollResponder = require('ScrollResponder');
var StaticRenderer = require('StaticRenderer');
var TimerMixin = require('react-timer-mixin');
var cloneReferencedElement = require('react-clone-referenced-element');
var isEmpty = require('isEmpty');
var merge = require('merge');
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;
/**
* 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 rowHasChanged 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, highlightRow);
* - renderSectionHeader(sectionData, sectionID);
*/
propTypes: {
...ScrollView.propTypes,
dataSource: PropTypes.instanceOf(ListViewDataSource).isRequired,
/**
* (sectionID, rowID, adjacentRowHighlighted) => renderable
*
* If provided, a renderable component to be rendered as the separator
* below each row but not the last row if there is a section header below.
* Take a sectionID and rowID of the row above and whether its adjacent row
* is highlighted.
*/
renderSeparator: PropTypes.func,
/**
* (rowData, sectionID, rowID, highlightRow) => 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. ListView can be notified when a row is
* being highlighted by calling highlightRow function. The separators above and
* below will be hidden when a row is highlighted. The highlighted state of
* a row can be reset by calling highlightRow(null).
*/
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 appears 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 (virtual, not physical) for calling onEndReached.
*/
onEndReachedThreshold: PropTypes.number,
/**
* Number of rows to render per event loop. Note: if your 'rows' are actually
* cells, i.e. they don't span the full width of your view (as in the
* ListViewGridLayoutExample), you should set the pageSize to be a multiple
* of the number of cells per row, otherwise you're likely to see gaps at
* the edge of the ListView as new pages are loaded.
*/
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,
/**
* (props) => renderable
*
* A function that returns the scrollable component in which the list rows
* are rendered. Defaults to returning a ScrollView with the given props.
*/
renderScrollComponent: React.PropTypes.func.isRequired,
/**
* 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,
/**
* A performance optimization for improving scroll perf of
* large lists, used in conjunction with overflow: 'hidden' on the row
* containers. This is enabled by default.
*/
removeClippedSubviews: React.PropTypes.bool,
/**
* An array of child indices determining which children get docked to the
* top of the screen when scrolling. For example, passing
* `stickyHeaderIndices={[0]}` will cause the first child to be fixed to the
* top of the scroll view. This property is not supported in conjunction
* with `horizontal={true}`.
* @platform ios
*/
stickyHeaderIndices: PropTypes.arrayOf(PropTypes.number),
/**
* Flag indicating whether empty section headers should be rendered. In the future release
* empty section headers will be rendered by default, and the flag will be deprecated.
* If empty sections are not desired to be rendered their indices should be excluded from sectionID object.
*/
enableEmptySections: PropTypes.bool,
},
/**
* Exports some data, e.g. for perf investigations or analytics.
*/
getMetrics: function() {
return {
contentLength: this.scrollProperties.contentLength,
totalRows: (this.props.enableEmptySections ? this.props.dataSource.getRowAndSectionCount() : this.props.dataSource.getRowCount()),
renderedRows: this.state.curRenderedRowsCount,
visibleRows: Object.keys(this._visibleRows).length,
};
},
/**
* Provides a handle to the underlying scroll responder.
* Note that `this._scrollComponent` might not be a `ScrollView`, so we
* need to check that it responds to `getScrollResponder` before calling it.
*/
getScrollResponder: function() {
if (this._scrollComponent && this._scrollComponent.getScrollResponder) {
return this._scrollComponent.getScrollResponder();
}
},
/**
* Scrolls to a given x, y offset, either immediately or with a smooth animation.
*
* See `ScrollView#scrollTo`.
*/
scrollTo: function(...args) {
if (this._scrollComponent && this._scrollComponent.scrollTo) {
this._scrollComponent.scrollTo(...args);
}
},
setNativeProps: function(props) {
if (this._scrollComponent) {
this._scrollComponent.setNativeProps(props);
}
},
/**
* React life cycle hooks.
*/
getDefaultProps: function() {
return {
initialListSize: DEFAULT_INITIAL_ROWS,
pageSize: DEFAULT_PAGE_SIZE,
renderScrollComponent: props => <ScrollView {...props} />,
scrollRenderAheadDistance: DEFAULT_SCROLL_RENDER_AHEAD,
onEndReachedThreshold: DEFAULT_END_REACHED_THRESHOLD,
stickyHeaderIndices: [],
};
},
getInitialState: function() {
return {
curRenderedRowsCount: this.props.initialListSize,
highlightedRow: {},
};
},
getInnerViewNode: function() {
return this._scrollComponent.getInnerViewNode();
},
componentWillMount: function() {
// this data should never trigger a render pass, so don't put in state
this.scrollProperties = {
visibleLength: null,
contentLength: null,
offset: 0
};
this._childFrames = [];
this._visibleRows = {};
this._prevRenderedRowsCount = 0;
this._sentEndForContentLength = null;
},
componentDidMount: function() {
// do this in animation frame until componentDidMount actually runs after
// the component is laid out
this.requestAnimationFrame(() => {
this._measureAndUpdateScrollProps();
});
},
componentWillReceiveProps: function(nextProps) {
if (this.props.dataSource !== nextProps.dataSource ||
this.props.initialListSize !== nextProps.initialListSize) {
this.setState((state, props) => {
this._prevRenderedRowsCount = 0;
return {
curRenderedRowsCount: Math.min(
Math.max(
state.curRenderedRowsCount,
props.initialListSize
),
props.enableEmptySections ? props.dataSource.getRowAndSectionCount() : props.dataSource.getRowCount()
),
};
}, () => this._renderMoreRowsIfNeeded());
}
},
componentDidUpdate: function() {
this.requestAnimationFrame(() => {
this._measureAndUpdateScrollProps();
});
},
_onRowHighlighted: function(sectionID, rowID) {
this.setState({highlightedRow: {sectionID, rowID}});
},
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) {
if (this.props.enableEmptySections === undefined) {
var warning = require('fbjs/lib/warning');
warning(false, 'In next release empty section headers will be rendered.'
+ ' In this release you can use \'enableEmptySections\' flag to render empty section headers.');
continue;
} else {
var invariant = require('fbjs/lib/invariant');
invariant(
this.props.enableEmptySections,
'In next release \'enableEmptySections\' flag will be deprecated, empty section headers will always be rendered.'
+ ' If empty section headers are not desirable their indices should be excluded from sectionIDs object.'
+ ' In this release \'enableEmptySections\' may only have value \'true\' to allow empty section headers rendering.');
}
}
if (this.props.renderSectionHeader) {
var shouldUpdateHeader = rowCount >= this._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._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,
this._onRowHighlighted
)}
/>;
bodyComponents.push(row);
totalIndex++;
if (this.props.renderSeparator &&
(rowIdx !== rowIDs.length - 1 || sectionIdx === allRowIDs.length - 1)) {
var adjacentRowHighlighted =
this.state.highlightedRow.sectionID === sectionID && (
this.state.highlightedRow.rowID === rowID ||
this.state.highlightedRow.rowID === rowIDs[rowIdx + 1]
);
var separator = this.props.renderSeparator(
sectionID,
rowID,
adjacentRowHighlighted
);
if (separator) {
bodyComponents.push(separator);
totalIndex++;
}
}
if (++rowCount === this.state.curRenderedRowsCount) {
break;
}
}
if (rowCount >= this.state.curRenderedRowsCount) {
break;
}
}
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(sectionHeaderIndices),
// 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,
}, 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) {
this._scrollComponent = scrollComponent;
},
_onContentSizeChange: function(width, height) {
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) {
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) {
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) {
return scrollProperties.contentLength - scrollProperties.visibleLength - scrollProperties.offset;
},
_updateVisibleRows: function(updatedFrames) {
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 (!frame) {
break;
}
var rowVisible = visibleSection[rowID];
var min = isVertical ? frame.y : frame.x;
var max = min + (isVertical ? frame.height : frame.width);
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) {
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;