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/**
* Copyright (c) Facebook, Inc. and its affiliates.
*
* This source code is licensed under the MIT license found in the
* LICENSE file in the root directory of this source tree.
*
* @format
* @flow strict-local
*/
'use strict';
const AnimatedImplementation = require('../../Animated/src/AnimatedImplementation');
const Platform = require('../../Utilities/Platform');
const React = require('react');
const ReactNative = require('../../Renderer/shims/ReactNative');
require('../../Renderer/shims/ReactNative'); // Force side effects to prevent T55744311
const ScrollResponder = require('../ScrollResponder');
const ScrollViewStickyHeader = require('./ScrollViewStickyHeader');
const StyleSheet = require('../../StyleSheet/StyleSheet');
const View = require('../View/View');
const dismissKeyboard = require('../../Utilities/dismissKeyboard');
const flattenStyle = require('../../StyleSheet/flattenStyle');
const invariant = require('invariant');
const processDecelerationRate = require('./processDecelerationRate');
const requireNativeComponent = require('../../ReactNative/requireNativeComponent');
const resolveAssetSource = require('../../Image/resolveAssetSource');
const splitLayoutProps = require('../../StyleSheet/splitLayoutProps');
import type {EdgeInsetsProp} from '../../StyleSheet/EdgeInsetsPropType';
import type {PointProp} from '../../StyleSheet/PointPropType';
import type {ViewStyleProp} from '../../StyleSheet/StyleSheet';
import type {ColorValue} from '../../StyleSheet/StyleSheetTypes';
import type {
PressEvent,
ScrollEvent,
LayoutEvent,
} from '../../Types/CoreEventTypes';
import type {HostComponent} from '../../Renderer/shims/ReactNativeTypes';
import type {State as ScrollResponderState} from '../ScrollResponder';
import type {ViewProps} from '../View/ViewPropTypes';
import type {Props as ScrollViewStickyHeaderProps} from './ScrollViewStickyHeader';
import ScrollViewNativeComponent from './ScrollViewNativeComponent';
import ScrollContentViewNativeComponent from './ScrollContentViewNativeComponent';
import AndroidHorizontalScrollViewNativeComponent from './AndroidHorizontalScrollViewNativeComponent';
import AndroidHorizontalScrollContentViewNativeComponent from './AndroidHorizontalScrollContentViewNativeComponent';
let AndroidScrollView;
let AndroidHorizontalScrollContentView;
let AndroidHorizontalScrollView;
let RCTScrollView;
let RCTScrollContentView;
if (Platform.OS === 'android') {
AndroidScrollView = ScrollViewNativeComponent;
AndroidHorizontalScrollView = AndroidHorizontalScrollViewNativeComponent;
AndroidHorizontalScrollContentView = AndroidHorizontalScrollContentViewNativeComponent;
} else if (Platform.OS === 'ios') {
RCTScrollView = ScrollViewNativeComponent;
RCTScrollContentView = ScrollContentViewNativeComponent;
} else {
RCTScrollView = requireNativeComponent('RCTScrollView');
RCTScrollContentView = requireNativeComponent('RCTScrollContentView');
}
export type ScrollResponderType = {
// We'd like to do ...ScrollView here, however Flow doesn't seem
// to see the imperative methods of ScrollView that way. Workaround the
// issue by specifying them manually.
getScrollableNode: $PropertyType<ScrollView, 'getScrollableNode'>,
getInnerViewNode: $PropertyType<ScrollView, 'getInnerViewNode'>,
getInnerViewRef: $PropertyType<ScrollView, 'getInnerViewRef'>,
getNativeScrollRef: $PropertyType<ScrollView, 'getNativeScrollRef'>,
setNativeProps: $PropertyType<ScrollView, 'setNativeProps'>,
scrollTo: $PropertyType<ScrollView, 'scrollTo'>,
flashScrollIndicators: $PropertyType<ScrollView, 'flashScrollIndicators'>,
...typeof ScrollResponder.Mixin,
...
};
type IOSProps = $ReadOnly<{|
/**
* 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?: ?boolean,
/**
* 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?: ?EdgeInsetsProp,
/**
* Used to manually set the starting scroll offset.
* The default value is `{x: 0, y: 0}`.
* @platform ios
*/
contentOffset?: ?PointProp,
/**
* 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?: ?boolean,
/**
* By default, ScrollView has an active pan responder that hijacks panresponders
* deeper in the render tree in order to prevent accidental touches while scrolling.
* However, in certain occasions (such as when using snapToInterval) in a vertical scrollview
* You may want to disable this behavior in order to prevent the ScrollView from blocking touches
*/
disableScrollViewPanResponder?: ?boolean,
/**
* 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?: ?boolean,
/**
* 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?: ?boolean,
/**
* 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?: ?boolean,
/**
* 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?: ?boolean,
/**
* 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?: ?('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?: ?boolean,
/**
* When false, once tracking starts, won't try to drag if the touch moves.
* The default value is true.
* @platform ios
*/
canCancelContentTouches?: ?boolean,
/**
* When set, the scroll view will adjust the scroll position so that the first child that is
* currently visible and at or beyond `minIndexForVisible` will not change position. This is
* useful for lists that are loading content in both directions, e.g. a chat thread, where new
* messages coming in might otherwise cause the scroll position to jump. A value of 0 is common,
* but other values such as 1 can be used to skip loading spinners or other content that should
* not maintain position.
*
* The optional `autoscrollToTopThreshold` can be used to make the content automatically scroll
* to the top after making the adjustment if the user was within the threshold of the top before
* the adjustment was made. This is also useful for chat-like applications where you want to see
* new messages scroll into place, but not if the user has scrolled up a ways and it would be
* disruptive to scroll a bunch.
*
* Caveat 1: Reordering elements in the scrollview with this enabled will probably cause
* jumpiness and jank. It can be fixed, but there are currently no plans to do so. For now,
* don't re-order the content of any ScrollViews or Lists that use this feature.
*
* Caveat 2: This simply uses `contentOffset` and `frame.origin` in native code to compute
* visibility. Occlusion, transforms, and other complexity won't be taken into account as to
* whether content is "visible" or not.
*
* @platform ios
*/
maintainVisibleContentPosition?: ?$ReadOnly<{|
minIndexForVisible: number,
autoscrollToTopThreshold?: ?number,
|}>,
/**
* The maximum allowed zoom scale. The default value is 1.0.
* @platform ios
*/
maximumZoomScale?: ?number,
/**
* The minimum allowed zoom scale. The default value is 1.0.
* @platform ios
*/
minimumZoomScale?: ?number,
/**
* When true, ScrollView allows use of pinch gestures to zoom in and out.
* The default value is true.
* @platform ios
*/
pinchGestureEnabled?: ?boolean,
/**
* 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.
*
* Values between 0 and 17ms indicate 60fps updates are needed and throttling
* will be disabled.
*
* 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?: ?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?: ?EdgeInsetsProp,
/**
* When true, the scroll view can be programmatically scrolled beyond its
* content size. The default value is false.
* @platform ios
*/
scrollToOverflowEnabled?: ?boolean,
/**
* When true, the scroll view scrolls to top when the status bar is tapped.
* The default value is true.
* @platform ios
*/
scrollsToTop?: ?boolean,
/**
* Fires when the scroll view scrolls to top after the status bar has been tapped
* @platform ios
*/
onScrollToTop?: (event: ScrollEvent) => void,
/**
* When true, shows a horizontal scroll indicator.
* The default value is true.
*/
showsHorizontalScrollIndicator?: ?boolean,
/**
* 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?: ?('start' | 'center' | 'end'),
/**
* The current scale of the scroll view content. The default value is 1.0.
* @platform ios
*/
zoomScale?: ?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?: ?(
| 'automatic'
| 'scrollableAxes'
| 'never'
| 'always'
),
/**
* 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?: ?boolean,
|}>;
type AndroidProps = $ReadOnly<{|
/**
* Enables nested scrolling for Android API level 21+.
* Nested scrolling is supported by default on iOS
* @platform android
*/
nestedScrollEnabled?: ?boolean,
/**
* 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?: ?ColorValue,
/**
* 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?: ?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?: ?('auto' | 'always' | 'never'),
/**
* Causes the scrollbars not to turn transparent when they are not in use.
* The default value is false.
*
* @platform android
*/
persistentScrollbar?: ?boolean,
/**
* Fades out the edges of the the scroll content.
*
* If the value is greater than 0, the fading edges will be set accordingly
* to the current scroll direction and position,
* indicating if there is more content to show.
*
* The default value is 0.
*
* @platform android
*/
fadingEdgeLength?: ?number,
|}>;
type VRProps = $ReadOnly<{|
/**
* Optionally an image can be used for the scroll bar thumb. This will
* override the color. While the image is loading or the image fails to
* load the color will be used instead. Use an alpha of 0 in the color
* to avoid seeing it while the image is loading.
*
* - `uri` - a string representing the resource identifier for the image, which
* should be either a local file path or the name of a static image resource
* - `number` - Opaque type returned by something like
* `import IMAGE from './image.jpg'`.
* @platform vr
*/
scrollBarThumbImage?: ?($ReadOnly<{||}> | number), // Opaque type returned by import IMAGE from './image.jpg'
|}>;
type StickyHeaderComponentType = React.AbstractComponent<
ScrollViewStickyHeaderProps,
$ReadOnly<{setNextHeaderY: number => void, ...}>,
>;
export type Props = $ReadOnly<{|
...ViewProps,
...IOSProps,
...AndroidProps,
...VRProps,
/**
* 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?: ?ViewStyleProp,
/**
* When true, the scroll view stops on the next index (in relation to scroll
* position at release) regardless of how fast the gesture is. This can be
* used for horizontal pagination when the page is less than the width of
* the ScrollView. The default value is false.
*/
disableIntervalMomentum?: ?boolean,
/**
* 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 on iOS, 0.985 on Android (the default)
* - `'fast'`: 0.99 on iOS, 0.9 on Android
*/
decelerationRate?: ?('fast' | 'normal' | 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?: ?boolean,
/**
* If sticky headers should stick at the bottom instead of the top of the
* ScrollView. This is usually used with inverted ScrollViews.
*/
invertStickyHeaders?: ?boolean,
/**
* 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?: ?// default
(| 'none' // cross-platform
| 'on-drag'
| '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?: ?('always' | 'never' | 'handled' | true | false),
/**
* Called when the momentum scroll starts (scroll which occurs as the ScrollView glides to a stop).
*/
onMomentumScrollBegin?: ?(event: ScrollEvent) => void,
/**
* Called when the momentum scroll ends (scroll which occurs as the ScrollView glides to a stop).
*/
onMomentumScrollEnd?: ?(event: ScrollEvent) => void,
/**
* Fires at most once per frame during scrolling. The frequency of the
* events can be controlled using the `scrollEventThrottle` prop.
*/
onScroll?: ?(event: ScrollEvent) => void,
/**
* Called when the user begins to drag the scroll view.
*/
onScrollBeginDrag?: ?(event: ScrollEvent) => void,
/**
* Called when the user stops dragging the scroll view and it either stops
* or begins to glide.
*/
onScrollEndDrag?: ?(event: ScrollEvent) => void,
/**
* 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?: (contentWidth: number, contentHeight: number) => void,
onKeyboardDidShow?: (event: PressEvent) => void,
/**
* 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?: ?boolean,
/**
* When false, the view cannot be scrolled via touch interaction.
* The default value is true.
*
* Note that the view can always be scrolled by calling `scrollTo`.
*/
scrollEnabled?: ?boolean,
/**
* When true, shows a vertical scroll indicator.
* The default value is true.
*/
showsVerticalScrollIndicator?: ?boolean,
/**
* 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?: ?$ReadOnlyArray<number>,
/**
* A React Component that will be used to render sticky headers.
* To be used together with `stickyHeaderIndices` or with `SectionList`, defaults to `ScrollViewStickyHeader`.
* You may need to set this if your sticky header uses custom transforms (eg. translation),
* for example when you want your list to have an animated hidable header.
*/
StickyHeaderComponent?: StickyHeaderComponentType,
/**
* 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.
*/
snapToInterval?: ?number,
/**
* When set, causes the scroll view to stop at the defined offsets.
* This can be used for paginating through variously sized children
* that have lengths smaller than the scroll view. Typically used in
* combination with `decelerationRate="fast"`.
*
* Overrides less configurable `pagingEnabled` and `snapToInterval` props.
*/
snapToOffsets?: ?$ReadOnlyArray<number>,
/**
* Use in conjunction with `snapToOffsets`. By default, the beginning
* of the list counts as a snap offset. Set `snapToStart` to false to disable
* this behavior and allow the list to scroll freely between its start and
* the first `snapToOffsets` offset.
* The default value is true.
*/
snapToStart?: ?boolean,
/**
* Use in conjunction with `snapToOffsets`. By default, the end
* of the list counts as a snap offset. Set `snapToEnd` to false to disable
* this behavior and allow the list to scroll freely between its end and
* the last `snapToOffsets` offset.
* The default value is true.
*/
snapToEnd?: ?boolean,
/**
* 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?: ?boolean,
/**
* 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).
*/
// $FlowFixMe - how to handle generic type without existential operator?
refreshControl?: ?React.Element<any>,
children?: React.Node,
|}>;
type State = {|
layoutHeight: ?number,
...ScrollResponderState,
|};
function createScrollResponder(
node: React.ElementRef<typeof ScrollView>,
): typeof ScrollResponder.Mixin {
const scrollResponder = {...ScrollResponder.Mixin};
for (const key in scrollResponder) {
if (typeof scrollResponder[key] === 'function') {
scrollResponder[key] = scrollResponder[key].bind(node);
}
}
return scrollResponder;
}
type ContextType = {|horizontal: boolean|} | null;
const Context = React.createContext<ContextType>(null);
const standardHorizontalContext: ContextType = Object.freeze({
horizontal: true,
});
const standardVerticalContext: ContextType = Object.freeze({horizontal: false});
/**
* 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.
*/
class ScrollView extends React.Component<Props, State> {
static Context: React$Context<ContextType> = Context;
/**
* Part 1: Removing ScrollResponder.Mixin:
*
* 1. Mixin methods should be flow typed. That's why we create a
* copy of ScrollResponder.Mixin and attach it to this._scrollResponder.
* Otherwise, we'd have to manually declare each method on the component
* class and assign it a flow type.
* 2. Mixin methods can call component methods, and access the component's
* props and state. So, we need to bind all mixin methods to the
* component instance.
* 3. Continued...
*/
_scrollResponder: typeof ScrollResponder.Mixin = createScrollResponder(this);
constructor(props: Props) {
super(props);
/**
* Part 2: Removing ScrollResponder.Mixin
*
* 3. Mixin methods access other mixin methods via dynamic dispatch using
* this. Since mixin methods are bound to the component instance, we need
* to copy all mixin methods to the component instance. This is also
* necessary because getScrollResponder() is a public method that returns
* an object that can be used to execute all scrollResponder methods.
* Since the object returned from that method is the ScrollView instance,
* we need to bind all mixin methods to the ScrollView instance.
*/
for (const key in ScrollResponder.Mixin) {
if (
typeof ScrollResponder.Mixin[key] === 'function' &&
key.startsWith('scrollResponder')
) {
// $FlowFixMe - dynamically adding properties to a class
(this: any)[key] = ScrollResponder.Mixin[key].bind(this);
}
}
/**
* Part 3: Removing ScrollResponder.Mixin
*
* 4. Mixins can initialize properties and use properties on the component
* instance.
*/
Object.keys(ScrollResponder.Mixin)
.filter(key => typeof ScrollResponder.Mixin[key] !== 'function')
.forEach(key => {
// $FlowFixMe - dynamically adding properties to a class
(this: any)[key] = ScrollResponder.Mixin[key];
});
}
_scrollAnimatedValue: AnimatedImplementation.Value = new AnimatedImplementation.Value(
0,
);
_scrollAnimatedValueAttachment: ?{detach: () => void, ...} = null;
_stickyHeaderRefs: Map<
string,
React.ElementRef<StickyHeaderComponentType>,
> = new Map();
_headerLayoutYs: Map<string, number> = new Map();
state: State = {
layoutHeight: null,
...ScrollResponder.Mixin.scrollResponderMixinGetInitialState(),
};
UNSAFE_componentWillMount() {
this._scrollResponder.UNSAFE_componentWillMount();
this._scrollAnimatedValue = new AnimatedImplementation.Value(
this.props.contentOffset ? this.props.contentOffset.y : 0,
);
this._scrollAnimatedValue.setOffset(
this.props.contentInset ? this.props.contentInset.top || 0 : 0,
);
this._stickyHeaderRefs = new Map();
this._headerLayoutYs = new Map();
}
UNSAFE_componentWillReceiveProps(nextProps: Props) {
const currentContentInsetTop = this.props.contentInset
? this.props.contentInset.top
: 0;
const nextContentInsetTop = nextProps.contentInset
? nextProps.contentInset.top
: 0;
if (currentContentInsetTop !== nextContentInsetTop) {
this._scrollAnimatedValue.setOffset(nextContentInsetTop || 0);
}
}
componentDidMount() {
this._updateAnimatedNodeAttachment();
}
componentDidUpdate() {
this._updateAnimatedNodeAttachment();
}
componentWillUnmount() {
this._scrollResponder.componentWillUnmount();
if (this._scrollAnimatedValueAttachment) {
this._scrollAnimatedValueAttachment.detach();
}
}
setNativeProps(props: {[key: string]: mixed, ...}) {
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(): ScrollResponderType {
// $FlowFixMe - overriding type to include ScrollResponder.Mixin
return ((this: any): ScrollResponderType);
}
getScrollableNode(): ?number {
return ReactNative.findNodeHandle(this._scrollViewRef);
}
getInnerViewNode(): ?number {
return ReactNative.findNodeHandle(this._innerViewRef);
}
getInnerViewRef(): ?React.ElementRef<HostComponent<mixed>> {
return this._innerViewRef;
}
getNativeScrollRef(): ?React.ElementRef<HostComponent<mixed>> {
return this._scrollViewRef;
}
/**
* 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(
options?:
| {
x?: number,
y?: number,
animated?: boolean,
...
}
| number,
deprecatedX?: number,
deprecatedAnimated?: boolean,
) {
let x, y, animated;
if (typeof options === 'number') {
console.warn(
'`scrollTo(y, x, animated)` is deprecated. Use `scrollTo({x: 5, y: 5, ' +
'animated: true})` instead.',
);
y = options;
x = deprecatedX;
animated = deprecatedAnimated;
} else if (options) {
y = options.y;
x = options.x;
animated = options.animated;
}
this._scrollResponder.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(options?: ?{animated?: boolean, ...}) {
// Default to true
const animated = (options && options.animated) !== false;
this._scrollResponder.scrollResponderScrollToEnd({
animated: animated,
});
}
/**
* Displays the scroll indicators momentarily.
*
* @platform ios
*/
flashScrollIndicators() {
this._scrollResponder.scrollResponderFlashScrollIndicators();
}
_getKeyForIndex(index, childArray) {
const child = childArray[index];
return child && child.key;
}
_updateAnimatedNodeAttachment() {
if (this._scrollAnimatedValueAttachment) {
this._scrollAnimatedValueAttachment.detach();
}
if (
this.props.stickyHeaderIndices &&
this.props.stickyHeaderIndices.length > 0
) {
this._scrollAnimatedValueAttachment = AnimatedImplementation.attachNativeEvent(
this._scrollViewRef,
'onScroll',
[{nativeEvent: {contentOffset: {y: this._scrollAnimatedValue}}}],
);
}
}
_setStickyHeaderRef(
key: string,
ref: ?React.ElementRef<StickyHeaderComponentType>,
) {
if (ref) {
this._stickyHeaderRefs.set(key, ref);
} else {
this._stickyHeaderRefs.delete(key);
}
}
_onStickyHeaderLayout(index, event, key) {
const {stickyHeaderIndices} = this.props;
if (!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 = stickyHeaderIndices.indexOf(index);
const previousHeaderIndex = stickyHeaderIndices[indexOfIndex - 1];
if (previousHeaderIndex != null) {
const previousHeader = this._stickyHeaderRefs.get(
this._getKeyForIndex(previousHeaderIndex, childArray),
);
previousHeader &&
previousHeader.setNextHeaderY &&
previousHeader.setNextHeaderY(layoutY);
}
}
_handleScroll = (e: ScrollEvent) => {
if (__DEV__) {
if (
this.props.onScroll &&
this.props.scrollEventThrottle == null &&
Platform.OS === 'ios'
) {
console.log(
'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' &&
this.state.isTouching
) {
dismissKeyboard();
}
}
this._scrollResponder.scrollResponderHandleScroll(e);
};
_handleLayout = (e: LayoutEvent) => {
if (this.props.invertStickyHeaders === true) {
this.setState({layoutHeight: e.nativeEvent.layout.height});
}
if (this.props.onLayout) {
this.props.onLayout(e);
}
};
_handleContentOnLayout = (e: LayoutEvent) => {
const {width, height} = e.nativeEvent.layout;
this.props.onContentSizeChange &&
this.props.onContentSizeChange(width, height);
};
_scrollViewRef: ?React.ElementRef<HostComponent<mixed>> = null;
_setScrollViewRef = (ref: ?React.ElementRef<HostComponent<mixed>>) => {
this._scrollViewRef = ref;
};
_innerViewRef: ?React.ElementRef<HostComponent<mixed>> = null;
_setInnerViewRef = (ref: ?React.ElementRef<HostComponent<mixed>>) => {
this._innerViewRef = ref;
};
render(): React.Node | React.Element<string> {
let ScrollViewClass;
let ScrollContentContainerViewClass;
if (Platform.OS === 'android') {
if (this.props.horizontal === true) {
ScrollViewClass = AndroidHorizontalScrollView;
ScrollContentContainerViewClass = AndroidHorizontalScrollContentView;
} else {
ScrollViewClass = AndroidScrollView;
ScrollContentContainerViewClass = View;
}
} else {
ScrollViewClass = RCTScrollView;
ScrollContentContainerViewClass = RCTScrollContentView;
}
invariant(
ScrollViewClass !== undefined,
'ScrollViewClass must not be undefined',
);
invariant(
ScrollContentContainerViewClass !== undefined,
'ScrollContentContainerViewClass must not be undefined',
);
const contentContainerStyle = [
this.props.horizontal === true && styles.contentContainerHorizontal,
this.props.contentContainerStyle,
];
if (__DEV__ && this.props.style !== undefined) {
const style = flattenStyle(this.props.style);
const childLayoutProps = ['alignItems', 'justifyContent'].filter(
prop => style && style[prop] !== undefined,
);
C2B
invariant(
childLayoutProps.length === 0,
'ScrollView child layout (' +