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/** | |
* 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 RCTScrollViewManager = require('NativeModules').ScrollViewManager; | |
var ScrollView = require('ScrollView'); | |
var ScrollResponder = require('ScrollResponder'); | |
var StaticRenderer = require('StaticRenderer'); | |
var TimerMixin = require('react-timer-mixin'); | |
var View = require('View'); | |
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 = 1; | |
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 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 the view in `SCROLLVIEW_REF` may not be a `ScrollView`, so we | |
* need to check that it responds to `getScrollResponder` before calling it. | |
*/ | |
getScrollResponder: function() { | |
return this.refs[SCROLLVIEW_REF] && | |
this.refs[SCROLLVIEW_REF].getScrollResponder && | |
this.refs[SCROLLVIEW_REF].getScrollResponder(); | |
}, | |
scrollTo: function(...args) { | |
this.refs[SCROLLVIEW_REF] && | |
this.refs[SCROLLVIEW_REF].scrollTo && | |
this.refs[SCROLLVIEW_REF].scrollTo(...args); | |
}, | |
setNativeProps: function(props) { | |
this.refs[SCROLLVIEW_REF] && | |
this.refs[SCROLLVIEW_REF].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: [], | |
childSizes: [] | |
}; | |
}, | |
getInitialState: function() { | |
return { | |
curRenderedRowsCount: this.props.initialListSize, | |
highlightedRow: {}, | |
}; | |
}, | |
getInnerViewNode: function() { | |
return this.refs[SCROLLVIEW_REF].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 isVisible = ( | |
!this._childFrames[totalIndex] || ( | |
this._visibleRows[sectionID] && | |
this._visibleRows[sectionID][rowID] | |
) | |
); | |
if (isVisible) { | |
// console.log('renderiing visible row', totalIndex) | |
var row = | |
<StaticRenderer | |
key={'r_' + comboID} | |
shouldUpdate={!!shouldUpdateRow} | |
render={this.props.renderRow.bind( | |
null, | |
dataSource.getRowData(sectionIdx, rowIdx), | |
sectionID, | |
rowID, | |
this.onRowHighlighted | |
)} | |
/>; | |
} else { | |
// console.log('renderiing offscreen row', totalIndex, this._childFrames[totalIndex]) | |
var row = <View key={'r_' + comboID} style={{height: this._childFrames[rowIdx].height, width: this._childFrames[rowIdx].width}} /> | |
} | |
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, | |
}); | |
// TODO(ide): Use function refs so we can compose with the scroll | |
// component's original ref instead of clobbering it | |
return React.cloneElement(renderScrollComponent(props), { | |
ref: SCROLLVIEW_REF, | |
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( | |
React.findNodeHandle(scrollComponent), | |
this._updateVisibleRows, | |
); | |
}, | |
_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() { | |
var updatedFrames = []; | |
if (this.props.withOptimizations !== false && this.props.dataSource._dataBlob.s1) { | |
let ySum = 0; | |
for (var i = 0; i < this.props.dataSource._dataBlob.s1.length; i++) { | |
let height; | |
if (this.props.childSizes[i]) { | |
// console.log('pushing layout', this.props.childSizes[i]) | |
updatedFrames.push({...this.props.childSizes[i], index: i}); | |
} else if (typeof this.props.defaultRowSize === 'number') { | |
updatedFrames.push({ | |
index: i, | |
x: 0, | |
y: ySum, | |
width: height, | |
height | |
}); | |
ySum += height; | |
} else if (typeof this.props.defaultRowSize === 'function') { | |
updatedFrames.push(this.props.defaultRowSize(i)); | |
} else { | |
// console.log('not including', i) | |
} | |
} | |
} | |
// if (!this.props.onChangeVisibleRows) { | |
// return; // No need to compute visible rows if there is no callback | |
// } | |
// console.log('updating visible', updatedFrames) | |
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 - this.scrollProperties.visibleLength; | |
var visibleMax = this.scrollProperties.offset + 2 * 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); | |
// console.log(visibleMin) | |
if (min > visibleMax || max < visibleMin) { | |
// console.log('outside of bounds', rowIdx, rowVisible) | |
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]; | |
} | |
} | |
if (visibilityChanged) { | |
// console.log('VISIBILITY CHANGES', this._visibleRows) | |
this.forceUpdate(); | |
} | |
visibilityChanged && this.props.onChangeVisibleRows && 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' | |
]; | |
// call this with e.nativeEvent.updatedChildFrames when ios | |
this._updateVisibleRows(); | |
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; |
@rturk a variant of this implementation is being used in this app, so probably yes https://github.com/terrysahaidak/GitterMobile/tree/master/libs/ListView
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Hi @sampurcell93 this looks great. The code is approx. 3month old, do you think it still valid? tks