react-native/Libraries/Components/ScrollView/ScrollView.js

865 lines
31 KiB
JavaScript

/**
* Copyright (c) 2015-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.
*
* @providesModule ScrollView
* @flow
*/
'use strict';
const Animated = require('Animated');
const ColorPropType = require('ColorPropType');
const EdgeInsetsPropType = require('EdgeInsetsPropType');
const Platform = require('Platform');
const PointPropType = require('PointPropType');
const PropTypes = require('prop-types');
const React = require('React');
const ReactNative = require('ReactNative');
const ScrollResponder = require('ScrollResponder');
const ScrollViewStickyHeader = require('ScrollViewStickyHeader');
const StyleSheet = require('StyleSheet');
const StyleSheetPropType = require('StyleSheetPropType');
const View = require('View');
const ViewPropTypes = require('ViewPropTypes');
const ViewStylePropTypes = require('ViewStylePropTypes');
const createReactClass = require('create-react-class');
const dismissKeyboard = require('dismissKeyboard');
const flattenStyle = require('flattenStyle');
const invariant = require('fbjs/lib/invariant');
const processDecelerationRate = require('processDecelerationRate');
const requireNativeComponent = require('requireNativeComponent');
const warning = require('fbjs/lib/warning');
import type {NativeMethodsMixinType} from 'ReactNativeTypes';
/**
* Component that wraps platform ScrollView while providing
* integration with touch locking "responder" system.
*
* Keep in mind that ScrollViews must have a bounded height in order to work,
* since they contain unbounded-height children into a bounded container (via
* a scroll interaction). In order to bound the height of a ScrollView, either
* set the height of the view directly (discouraged) or make sure all parent
* views have bounded height. Forgetting to transfer `{flex: 1}` down the
* view stack can lead to errors here, which the element inspector makes
* easy to debug.
*
* Doesn't yet support other contained responders from blocking this scroll
* view from becoming the responder.
*
*
* `<ScrollView>` vs [`<FlatList>`](/react-native/docs/flatlist.html) - which one to use?
*
* `ScrollView` simply renders all its react child components at once. That
* makes it very easy to understand and use.
*
* On the other hand, this has a performance downside. Imagine you have a very
* long list of items you want to display, maybe several screens worth of
* content. Creating JS components and native views for everything all at once,
* much of which may not even be shown, will contribute to slow rendering and
* increased memory usage.
*
* This is where `FlatList` comes into play. `FlatList` renders items lazily,
* just when they are about to appear, and removes items that scroll way off
* screen to save memory and processing time.
*
* `FlatList` is also handy if you want to render separators between your items,
* multiple columns, infinite scroll loading, or any number of other features it
* supports out of the box.
*/
// $FlowFixMe(>=0.41.0)
const ScrollView = createReactClass({
displayName: 'ScrollView',
propTypes: {
...ViewPropTypes,
/**
* Controls whether iOS should automatically adjust the content inset
* for scroll views that are placed behind a navigation bar or
* tab bar/ toolbar. The default value is true.
* @platform ios
*/
automaticallyAdjustContentInsets: PropTypes.bool,
/**
* The amount by which the scroll view content is inset from the edges
* of the scroll view. Defaults to `{top: 0, left: 0, bottom: 0, right: 0}`.
* @platform ios
*/
contentInset: EdgeInsetsPropType,
/**
* Used to manually set the starting scroll offset.
* The default value is `{x: 0, y: 0}`.
* @platform ios
*/
contentOffset: PointPropType,
/**
* When true, the scroll view bounces when it reaches the end of the
* content if the content is larger then the scroll view along the axis of
* the scroll direction. When false, it disables all bouncing even if
* the `alwaysBounce*` props are true. The default value is true.
* @platform ios
*/
bounces: PropTypes.bool,
/**
* When true, gestures can drive zoom past min/max and the zoom will animate
* to the min/max value at gesture end, otherwise the zoom will not exceed
* the limits.
* @platform ios
*/
bouncesZoom: PropTypes.bool,
/**
* When true, the scroll view bounces horizontally when it reaches the end
* even if the content is smaller than the scroll view itself. The default
* value is true when `horizontal={true}` and false otherwise.
* @platform ios
*/
alwaysBounceHorizontal: PropTypes.bool,
/**
* When true, the scroll view bounces vertically when it reaches the end
* even if the content is smaller than the scroll view itself. The default
* value is false when `horizontal={true}` and true otherwise.
* @platform ios
*/
alwaysBounceVertical: PropTypes.bool,
/**
* When true, the scroll view automatically centers the content when the
* content is smaller than the scroll view bounds; when the content is
* larger than the scroll view, this property has no effect. The default
* value is false.
* @platform ios
*/
centerContent: PropTypes.bool,
/**
* These styles will be applied to the scroll view content container which
* wraps all of the child views. Example:
*
* ```
* return (
* <ScrollView contentContainerStyle={styles.contentContainer}>
* </ScrollView>
* );
* ...
* const styles = StyleSheet.create({
* contentContainer: {
* paddingVertical: 20
* }
* });
* ```
*/
contentContainerStyle: StyleSheetPropType(ViewStylePropTypes),
/**
* A floating-point number that determines how quickly the scroll view
* decelerates after the user lifts their finger. You may also use string
* shortcuts `"normal"` and `"fast"` which match the underlying iOS settings
* for `UIScrollViewDecelerationRateNormal` and
* `UIScrollViewDecelerationRateFast` respectively.
*
* - `'normal'`: 0.998 (the default)
* - `'fast'`: 0.99
*
* @platform ios
*/
decelerationRate: PropTypes.oneOfType([
PropTypes.oneOf(['fast', 'normal']),
PropTypes.number,
]),
/**
* When true, the scroll view's children are arranged horizontally in a row
* instead of vertically in a column. The default value is false.
*/
horizontal: PropTypes.bool,
/**
* The style of the scroll indicators.
*
* - `'default'` (the default), same as `black`.
* - `'black'`, scroll indicator is black. This style is good against a light background.
* - `'white'`, scroll indicator is white. This style is good against a dark background.
*
* @platform ios
*/
indicatorStyle: PropTypes.oneOf([
'default', // default
'black',
'white',
]),
/**
* When true, the ScrollView will try to lock to only vertical or horizontal
* scrolling while dragging. The default value is false.
* @platform ios
*/
directionalLockEnabled: PropTypes.bool,
/**
* When false, once tracking starts, won't try to drag if the touch moves.
* The default value is true.
* @platform ios
*/
canCancelContentTouches: PropTypes.bool,
/**
* Determines whether the keyboard gets dismissed in response to a drag.
*
* *Cross platform*
*
* - `'none'` (the default), drags do not dismiss the keyboard.
* - `'on-drag'`, the keyboard is dismissed when a drag begins.
*
* *iOS Only*
*
* - `'interactive'`, the keyboard is dismissed interactively with the drag and moves in
* synchrony with the touch; dragging upwards cancels the dismissal.
* On android this is not supported and it will have the same behavior as 'none'.
*/
keyboardDismissMode: PropTypes.oneOf([
'none', // default
'on-drag', // Cross-platform
'interactive', // iOS-only
]),
/**
* Determines when the keyboard should stay visible after a tap.
*
* - `'never'` (the default), tapping outside of the focused text input when the keyboard
* is up dismisses the keyboard. When this happens, children won't receive the tap.
* - `'always'`, the keyboard will not dismiss automatically, and the scroll view will not
* catch taps, but children of the scroll view can catch taps.
* - `'handled'`, the keyboard will not dismiss automatically when the tap was handled by
* a children, (or captured by an ancestor).
* - `false`, deprecated, use 'never' instead
* - `true`, deprecated, use 'always' instead
*/
keyboardShouldPersistTaps: PropTypes.oneOf(['always', 'never', 'handled', false, true]),
/**
* The maximum allowed zoom scale. The default value is 1.0.
* @platform ios
*/
maximumZoomScale: PropTypes.number,
/**
* The minimum allowed zoom scale. The default value is 1.0.
* @platform ios
*/
minimumZoomScale: PropTypes.number,
/**
* Called when the momentum scroll starts (scroll which occurs as the ScrollView glides to a stop).
*/
onMomentumScrollBegin: PropTypes.func,
/**
* Called when the momentum scroll ends (scroll which occurs as the ScrollView glides to a stop).
*/
onMomentumScrollEnd: PropTypes.func,
/**
* Fires at most once per frame during scrolling. The frequency of the
* events can be controlled using the `scrollEventThrottle` prop.
*/
onScroll: PropTypes.func,
/**
* Called when scrollable content view of the ScrollView changes.
*
* Handler function is passed the content width and content height as parameters:
* `(contentWidth, contentHeight)`
*
* It's implemented using onLayout handler attached to the content container
* which this ScrollView renders.
*/
onContentSizeChange: PropTypes.func,
/**
* When true, the scroll view stops on multiples of the scroll view's size
* when scrolling. This can be used for horizontal pagination. The default
* value is false.
*
* Note: Vertical pagination is not supported on Android.
*/
pagingEnabled: PropTypes.bool,
/**
* When false, the view cannot be scrolled via touch interaction.
* The default value is true.
*
* Note that the view can be always be scrolled by calling `scrollTo`.
*/
scrollEnabled: PropTypes.bool,
/**
* This controls how often the scroll event will be fired while scrolling
* (as a time interval in ms). A lower number yields better accuracy for code
* that is tracking the scroll position, but can lead to scroll performance
* problems due to the volume of information being send over the bridge.
* You will not notice a difference between values set between 1-16 as the
* JS run loop is synced to the screen refresh rate. If you do not need precise
* scroll position tracking, set this value higher to limit the information
* being sent across the bridge. The default value is zero, which results in
* the scroll event being sent only once each time the view is scrolled.
* @platform ios
*/
scrollEventThrottle: PropTypes.number,
/**
* The amount by which the scroll view indicators are inset from the edges
* of the scroll view. This should normally be set to the same value as
* the `contentInset`. Defaults to `{0, 0, 0, 0}`.
* @platform ios
*/
scrollIndicatorInsets: EdgeInsetsPropType,
/**
* When true, the scroll view scrolls to top when the status bar is tapped.
* The default value is true.
* @platform ios
*/
scrollsToTop: PropTypes.bool,
/**
* When true, shows a horizontal scroll indicator.
* The default value is true.
*/
showsHorizontalScrollIndicator: PropTypes.bool,
/**
* When true, shows a vertical scroll indicator.
* The default value is true.
*/
showsVerticalScrollIndicator: 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}`.
*/
stickyHeaderIndices: PropTypes.arrayOf(PropTypes.number),
style: StyleSheetPropType(ViewStylePropTypes),
/**
* When set, causes the scroll view to stop at multiples of the value of
* `snapToInterval`. This can be used for paginating through children
* that have lengths smaller than the scroll view. Typically used in
* combination with `snapToAlignment` and `decelerationRate="fast"`.
* Overrides less configurable `pagingEnabled` prop.
*
* @platform ios
*/
snapToInterval: PropTypes.number,
/**
* When `snapToInterval` is set, `snapToAlignment` will define the relationship
* of the snapping to the scroll view.
*
* - `'start'` (the default) will align the snap at the left (horizontal) or top (vertical)
* - `'center'` will align the snap in the center
* - `'end'` will align the snap at the right (horizontal) or bottom (vertical)
*
* @platform ios
*/
snapToAlignment: PropTypes.oneOf([
'start', // default
'center',
'end',
]),
/**
* Experimental: When true, offscreen child views (whose `overflow` value is
* `hidden`) are removed from their native backing superview when offscreen.
* This can improve scrolling performance on long lists. The default value is
* true.
*/
removeClippedSubviews: PropTypes.bool,
/**
* The current scale of the scroll view content. The default value is 1.0.
* @platform ios
*/
zoomScale: PropTypes.number,
/**
* This property specifies how the safe area insets are used to modify the
* content area of the scroll view. The default value of this property is
* "never". Available on iOS 11 and later.
* @platform ios
*/
contentInsetAdjustmentBehavior: PropTypes.oneOf([
'automatic',
'scrollableAxes',
'never', // default
'always',
]),
/**
* A RefreshControl component, used to provide pull-to-refresh
* functionality for the ScrollView. Only works for vertical ScrollViews
* (`horizontal` prop must be `false`).
*
* See [RefreshControl](docs/refreshcontrol.html).
*/
refreshControl: PropTypes.element,
/**
* Sometimes a scrollview takes up more space than its content fills. When this is
* the case, this prop will fill the rest of the scrollview with a color to avoid setting
* a background and creating unnecessary overdraw. This is an advanced optimization
* that is not needed in the general case.
* @platform android
*/
endFillColor: ColorPropType,
/**
* Tag used to log scroll performance on this scroll view. Will force
* momentum events to be turned on (see sendMomentumEvents). This doesn't do
* anything out of the box and you need to implement a custom native
* FpsListener for it to be useful.
* @platform android
*/
scrollPerfTag: PropTypes.string,
/**
* Used to override default value of overScroll mode.
*
* Possible values:
*
* - `'auto'` - Default value, allow a user to over-scroll
* this view only if the content is large enough to meaningfully scroll.
* - `'always'` - Always allow a user to over-scroll this view.
* - `'never'` - Never allow a user to over-scroll this view.
*
* @platform android
*/
overScrollMode: PropTypes.oneOf([
'auto',
'always',
'never',
]),
/**
* When true, ScrollView will emit updateChildFrames data in scroll events,
* otherwise will not compute or emit child frame data. This only exists
* to support legacy issues, `onLayout` should be used instead to retrieve
* frame data.
* The default value is false.
* @platform ios
*/
DEPRECATED_sendUpdatedChildFrames: PropTypes.bool,
},
mixins: [ScrollResponder.Mixin],
_scrollAnimatedValue: (new Animated.Value(0): Animated.Value),
_scrollAnimatedValueAttachment: (null: ?{detach: () => void}),
_stickyHeaderRefs: (new Map(): Map<number, ScrollViewStickyHeader>),
_headerLayoutYs: (new Map(): Map<string, number>),
getInitialState: function() {
return this.scrollResponderMixinGetInitialState();
},
componentWillMount: function() {
this._scrollAnimatedValue = new Animated.Value(0);
this._stickyHeaderRefs = new Map();
this._headerLayoutYs = new Map();
},
componentDidMount: function() {
this._updateAnimatedNodeAttachment();
},
componentDidUpdate: function() {
this._updateAnimatedNodeAttachment();
},
componentWillUnmount: function() {
if (this._scrollAnimatedValueAttachment) {
this._scrollAnimatedValueAttachment.detach();
}
},
setNativeProps: function(props: Object) {
this._scrollViewRef && this._scrollViewRef.setNativeProps(props);
},
/**
* Returns a reference to the underlying scroll responder, which supports
* operations like `scrollTo`. All ScrollView-like components should
* implement this method so that they can be composed while providing access
* to the underlying scroll responder's methods.
*/
getScrollResponder: function(): ScrollView {
return this;
},
getScrollableNode: function(): any {
return ReactNative.findNodeHandle(this._scrollViewRef);
},
getInnerViewNode: function(): any {
return ReactNative.findNodeHandle(this._innerViewRef);
},
/**
* Scrolls to a given x, y offset, either immediately or with a smooth animation.
*
* Example:
*
* `scrollTo({x: 0, y: 0, animated: true})`
*
* Note: The weird function signature is due to the fact that, for historical reasons,
* the function also accepts separate arguments as an alternative to the options object.
* This is deprecated due to ambiguity (y before x), and SHOULD NOT BE USED.
*/
scrollTo: function(
y?: number | { x?: number, y?: number, animated?: boolean },
x?: number,
animated?: boolean
) {
if (typeof y === 'number') {
console.warn('`scrollTo(y, x, animated)` is deprecated. Use `scrollTo({x: 5, y: 5, ' +
'animated: true})` instead.');
} else {
({x, y, animated} = y || {});
}
this.getScrollResponder().scrollResponderScrollTo(
{x: x || 0, y: y || 0, animated: animated !== false}
);
},
/**
* If this is a vertical ScrollView scrolls to the bottom.
* If this is a horizontal ScrollView scrolls to the right.
*
* Use `scrollToEnd({animated: true})` for smooth animated scrolling,
* `scrollToEnd({animated: false})` for immediate scrolling.
* If no options are passed, `animated` defaults to true.
*/
scrollToEnd: function(
options?: { animated?: boolean },
) {
// Default to true
const animated = (options && options.animated) !== false;
this.getScrollResponder().scrollResponderScrollToEnd({
animated: animated,
});
},
/**
* Deprecated, use `scrollTo` instead.
*/
scrollWithoutAnimationTo: function(y: number = 0, x: number = 0) {
console.warn('`scrollWithoutAnimationTo` is deprecated. Use `scrollTo` instead');
this.scrollTo({x, y, animated: false});
},
/**
* Displays the scroll indicators momentarily.
*
* @platform ios
*/
flashScrollIndicators: function() {
this.getScrollResponder().scrollResponderFlashScrollIndicators();
},
_getKeyForIndex: function(index, childArray) {
const child = childArray[index];
return child && child.key;
},
_updateAnimatedNodeAttachment: function() {
if (this._scrollAnimatedValueAttachment) {
this._scrollAnimatedValueAttachment.detach();
}
if (this.props.stickyHeaderIndices && this.props.stickyHeaderIndices.length > 0) {
this._scrollAnimatedValueAttachment = Animated.attachNativeEvent(
this._scrollViewRef,
'onScroll',
[{nativeEvent: {contentOffset: {y: this._scrollAnimatedValue}}}]
);
}
},
_setStickyHeaderRef: function(key, ref) {
if (ref) {
this._stickyHeaderRefs.set(key, ref);
} else {
this._stickyHeaderRefs.delete(key);
}
},
_onStickyHeaderLayout: function(index, event, key) {
if (!this.props.stickyHeaderIndices) {
return;
}
const childArray = React.Children.toArray(this.props.children);
if (key !== this._getKeyForIndex(index, childArray)) {
// ignore stale layout update
return;
}
const layoutY = event.nativeEvent.layout.y;
this._headerLayoutYs.set(key, layoutY);
const indexOfIndex = this.props.stickyHeaderIndices.indexOf(index);
const previousHeaderIndex = this.props.stickyHeaderIndices[indexOfIndex - 1];
if (previousHeaderIndex != null) {
const previousHeader = this._stickyHeaderRefs.get(
this._getKeyForIndex(previousHeaderIndex, childArray)
);
previousHeader && previousHeader.setNextHeaderY(layoutY);
}
},
_handleScroll: function(e: Object) {
if (__DEV__) {
if (this.props.onScroll && this.props.scrollEventThrottle == null && Platform.OS === 'ios') {
console.log( // eslint-disable-line no-console-disallow
'You specified `onScroll` on a <ScrollView> but not ' +
'`scrollEventThrottle`. You will only receive one event. ' +
'Using `16` you get all the events but be aware that it may ' +
'cause frame drops, use a bigger number if you don\'t need as ' +
'much precision.'
);
}
}
if (Platform.OS === 'android') {
if (this.props.keyboardDismissMode === 'on-drag') {
dismissKeyboard();
}
}
this.scrollResponderHandleScroll(e);
},
_handleContentOnLayout: function(e: Object) {
const {width, height} = e.nativeEvent.layout;
this.props.onContentSizeChange && this.props.onContentSizeChange(width, height);
},
_scrollViewRef: (null: ?ScrollView),
_setScrollViewRef: function(ref: ?ScrollView) {
this._scrollViewRef = ref;
},
_innerViewRef: (null: ?NativeMethodsMixinType),
_setInnerViewRef: function(ref: ?NativeMethodsMixinType) {
this._innerViewRef = ref;
},
render: function() {
let ScrollViewClass;
let ScrollContentContainerViewClass;
if (Platform.OS === 'ios') {
ScrollViewClass = RCTScrollView;
ScrollContentContainerViewClass = RCTScrollContentView;
warning(
!this.props.snapToInterval || !this.props.pagingEnabled,
'snapToInterval is currently ignored when pagingEnabled is true.'
);
} else if (Platform.OS === 'android') {
if (this.props.horizontal) {
ScrollViewClass = AndroidHorizontalScrollView;
} else {
ScrollViewClass = AndroidScrollView;
}
ScrollContentContainerViewClass = View;
}
invariant(
ScrollViewClass !== undefined,
'ScrollViewClass must not be undefined'
);
invariant(
ScrollContentContainerViewClass !== undefined,
'ScrollContentContainerViewClass must not be undefined'
);
const contentContainerStyle = [
this.props.horizontal && styles.contentContainerHorizontal,
this.props.contentContainerStyle,
];
let style, childLayoutProps;
if (__DEV__ && this.props.style) {
style = flattenStyle(this.props.style);
childLayoutProps = ['alignItems', 'justifyContent']
.filter((prop) => style && style[prop] !== undefined);
invariant(
childLayoutProps.length === 0,
'ScrollView child layout (' + JSON.stringify(childLayoutProps) +
') must be applied through the contentContainerStyle prop.'
);
}
let contentSizeChangeProps = {};
if (this.props.onContentSizeChange) {
contentSizeChangeProps = {
onLayout: this._handleContentOnLayout,
};
}
const {stickyHeaderIndices} = this.props;
const hasStickyHeaders = stickyHeaderIndices && stickyHeaderIndices.length > 0;
const childArray = hasStickyHeaders && React.Children.toArray(this.props.children);
const children = hasStickyHeaders ?
childArray.map((child, index) => {
const indexOfIndex = child ? stickyHeaderIndices.indexOf(index) : -1;
if (indexOfIndex > -1) {
const key = child.key;
const nextIndex = stickyHeaderIndices[indexOfIndex + 1];
return (
<ScrollViewStickyHeader
key={key}
ref={(ref) => this._setStickyHeaderRef(key, ref)}
nextHeaderLayoutY={
this._headerLayoutYs.get(this._getKeyForIndex(nextIndex, childArray))
}
onLayout={(event) => this._onStickyHeaderLayout(index, event, key)}
scrollAnimatedValue={this._scrollAnimatedValue}>
{child}
</ScrollViewStickyHeader>
);
} else {
return child;
}
}) :
this.props.children;
const contentContainer =
<ScrollContentContainerViewClass
{...contentSizeChangeProps}
ref={this._setInnerViewRef}
style={contentContainerStyle}
removeClippedSubviews={
// Subview clipping causes issues with sticky headers on Android and
// would be hard to fix properly in a performant way.
Platform.OS === 'android' && hasStickyHeaders ?
false :
this.props.removeClippedSubviews
}
collapsable={false}>
{children}
</ScrollContentContainerViewClass>;
const alwaysBounceHorizontal =
this.props.alwaysBounceHorizontal !== undefined ?
this.props.alwaysBounceHorizontal :
this.props.horizontal;
const alwaysBounceVertical =
this.props.alwaysBounceVertical !== undefined ?
this.props.alwaysBounceVertical :
!this.props.horizontal;
const DEPRECATED_sendUpdatedChildFrames =
!!this.props.DEPRECATED_sendUpdatedChildFrames;
const baseStyle = this.props.horizontal ? styles.baseHorizontal : styles.baseVertical;
const props = {
...this.props,
alwaysBounceHorizontal,
alwaysBounceVertical,
style: ([baseStyle, this.props.style]: ?Array<any>),
// Override the onContentSizeChange from props, since this event can
// bubble up from TextInputs
onContentSizeChange: null,
onMomentumScrollBegin: this.scrollResponderHandleMomentumScrollBegin,
onMomentumScrollEnd: this.scrollResponderHandleMomentumScrollEnd,
onResponderGrant: this.scrollResponderHandleResponderGrant,
onResponderReject: this.scrollResponderHandleResponderReject,
onResponderRelease: this.scrollResponderHandleResponderRelease,
onResponderTerminate: this.scrollResponderHandleTerminate,
onResponderTerminationRequest: this.scrollResponderHandleTerminationRequest,
onScroll: this._handleScroll,
onScrollBeginDrag: this.scrollResponderHandleScrollBeginDrag,
onScrollEndDrag: this.scrollResponderHandleScrollEndDrag,
onScrollShouldSetResponder: this.scrollResponderHandleScrollShouldSetResponder,
onStartShouldSetResponder: this.scrollResponderHandleStartShouldSetResponder,
onStartShouldSetResponderCapture: this.scrollResponderHandleStartShouldSetResponderCapture,
onTouchEnd: this.scrollResponderHandleTouchEnd,
onTouchMove: this.scrollResponderHandleTouchMove,
onTouchStart: this.scrollResponderHandleTouchStart,
scrollEventThrottle: hasStickyHeaders ? 1 : this.props.scrollEventThrottle,
sendMomentumEvents: (this.props.onMomentumScrollBegin || this.props.onMomentumScrollEnd) ?
true : false,
DEPRECATED_sendUpdatedChildFrames,
};
const { decelerationRate } = this.props;
if (decelerationRate) {
props.decelerationRate = processDecelerationRate(decelerationRate);
}
const refreshControl = this.props.refreshControl;
if (refreshControl) {
if (Platform.OS === 'ios') {
// On iOS the RefreshControl is a child of the ScrollView.
// tvOS lacks native support for RefreshControl, so don't include it in that case
return (
<ScrollViewClass {...props} ref={this._setScrollViewRef}>
{Platform.isTVOS ? null : refreshControl}
{contentContainer}
</ScrollViewClass>
);
} else if (Platform.OS === 'android') {
// On Android wrap the ScrollView with a AndroidSwipeRefreshLayout.
// Since the ScrollView is wrapped add the style props to the
// AndroidSwipeRefreshLayout and use flex: 1 for the ScrollView.
// Note: we should only apply props.style on the wrapper
// however, the ScrollView still needs the baseStyle to be scrollable
return React.cloneElement(
refreshControl,
{style: props.style},
<ScrollViewClass {...props} style={baseStyle} ref={this._setScrollViewRef}>
{contentContainer}
</ScrollViewClass>
);
}
}
return (
<ScrollViewClass {...props} ref={this._setScrollViewRef}>
{contentContainer}
</ScrollViewClass>
);
}
});
const styles = StyleSheet.create({
baseVertical: {
flexGrow: 1,
flexShrink: 1,
flexDirection: 'column',
overflow: 'scroll',
},
baseHorizontal: {
flexGrow: 1,
flexShrink: 1,
flexDirection: 'row',
overflow: 'scroll',
},
contentContainerHorizontal: {
flexDirection: 'row',
},
});
let nativeOnlyProps,
AndroidScrollView,
AndroidHorizontalScrollView,
RCTScrollView,
RCTScrollContentView;
if (Platform.OS === 'android') {
nativeOnlyProps = {
nativeOnly: {
sendMomentumEvents: true,
}
};
AndroidScrollView = requireNativeComponent(
'RCTScrollView',
(ScrollView: ReactClass<any>),
nativeOnlyProps
);
AndroidHorizontalScrollView = requireNativeComponent(
'AndroidHorizontalScrollView',
(ScrollView: ReactClass<any>),
nativeOnlyProps
);
} else if (Platform.OS === 'ios') {
nativeOnlyProps = {
nativeOnly: {
onMomentumScrollBegin: true,
onMomentumScrollEnd : true,
onScrollBeginDrag: true,
onScrollEndDrag: true,
}
};
RCTScrollView = requireNativeComponent(
'RCTScrollView',
(ScrollView: ReactClass<any>),
nativeOnlyProps,
);
// $FlowFixMe (bvaughn) Update ComponentInterface in ViewPropTypes to include a string type (for Fiber host components) in a follow-up.
RCTScrollContentView = requireNativeComponent('RCTScrollContentView', View);
}
module.exports = ScrollView;