AccessibilityInfo
Sometimes it's useful to know whether or not the device has a screen reader that is currently active. The AccessibilityInfo
API is designed for this purpose. You can use it to query the current state of the screen reader as well as to register to be notified when the state of the screen reader changes.
Here's a small example illustrating how to use AccessibilityInfo
:
class AccessibilityStatusExample extends React.Component { state = { reduceMotionEnabled: false, screenReaderEnabled: false };
componentDidMount() { AccessibilityInfo.addEventListener( 'reduceMotionChanged', this._handleReduceMotionToggled ); AccessibilityInfo.addEventListener( 'screenReaderChanged', this._handleScreenReaderToggled );
AccessibilityInfo.isReduceMotionEnabled().then( (reduceMotionEnabled) => { this.setState({ reduceMotionEnabled }); } ); AccessibilityInfo.isScreenReaderEnabled().then( (screenReaderEnabled) => { this.setState({ screenReaderEnabled }); } ); }
componentWillUnmount() { AccessibilityInfo.removeEventListener( 'reduceMotionChanged', this._handleReduceMotionToggled );
AccessibilityInfo.removeEventListener( 'screenReaderChanged', this._handleScreenReaderToggled ); }
_handleReduceMotionToggled = (reduceMotionEnabled) => { this.setState({ reduceMotionEnabled }); };
_handleScreenReaderToggled = (screenReaderEnabled) => { this.setState({ screenReaderEnabled }); };
render() { return ( <View> <Text> The reduce motion is{' '} {this.state.reduceMotionEnabled ? 'enabled' : 'disabled'} . </Text> <Text> The screen reader is{' '} {this.state.screenReaderEnabled ? 'enabled' : 'disabled'} . </Text> </View> ); }}
Reference
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MethodsisBoldTextEnabled()
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static isBoldTextEnabled()
iOS-Only. Query whether a bold text is currently enabled. Returns a promise which resolves to a boolean. The result is true
when bold text is enabled and false
otherwise.
isGrayscaleEnabled()
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static isGrayscaleEnabled()
iOS-Only. Query whether grayscale is currently enabled. Returns a promise which resolves to a boolean. The result is true
when grayscale is enabled and false
otherwise.
isInvertColorsEnabled()
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static isInvertColorsEnabled()
iOS-Only. Query whether invert colors is currently enabled. Returns a promise which resolves to a boolean. The result is true
when invert colors is enabled and false
otherwise.
isReduceMotionEnabled()
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static isReduceMotionEnabled()
Query whether reduce motion is currently enabled. Returns a promise which resolves to a boolean. The result is true
when reduce motion is enabled and false
otherwise.
isReduceTransparencyEnabled()
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static isReduceTransparencyEnabled()
iOS-Only. Query whether reduce transparency is currently enabled. Returns a promise which resolves to a boolean. The result is true
when a reduce transparency is enabled and false
otherwise.
isScreenReaderEnabled()
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static isScreenReaderEnabled()
Query whether a screen reader is currently enabled. Returns a promise which resolves to a boolean. The result is true
when a screen reader is enabled and false
otherwise.
addEventListener()
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static addEventListener(eventName, handler)
Add an event handler. Supported events:
boldTextChanged
: iOS-only event. Fires when the state of the bold text toggle changes. The argument to the event handler is a boolean. The boolean istrue
when bold text is enabled andfalse
otherwise.grayscaleChanged
: iOS-only event. Fires when the state of the gray scale toggle changes. The argument to the event handler is a boolean. The boolean istrue
when a gray scale is enabled andfalse
otherwise.invertColorsChanged
: iOS-only event. Fires when the state of the invert colors toggle changes. The argument to the event handler is a boolean. The boolean istrue
when invert colors is enabled andfalse
otherwise.reduceMotionChanged
: Fires when the state of the reduce motion toggle changes. The argument to the event handler is a boolean. The boolean istrue
when a reduce motion is enabled (or when "Transition Animation Scale" in "Developer options" is "Animation off") andfalse
otherwise.screenReaderChanged
: Fires when the state of the screen reader changes. The argument to the event handler is a boolean. The boolean istrue
when a screen reader is enabled andfalse
otherwise.reduceTransparencyChanged
: iOS-only event. Fires when the state of the reduce transparency toggle changes. The argument to the event handler is a boolean. The boolean istrue
when reduce transparency is enabled andfalse
otherwise.announcementFinished
: iOS-only event. Fires when the screen reader has finished making an announcement. The argument to the event handler is a dictionary with these keys:announcement
: The string announced by the screen reader.success
: A boolean indicating whether the announcement was successfully made.
setAccessibilityFocus()
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static setAccessibilityFocus(reactTag)
Set accessibility focus to a React component. On Android, this is equivalent to UIManager.sendAccessibilityEvent(reactTag, UIManager.AccessibilityEventTypes.typeViewFocused);
.
announceForAccessibility()
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static announceForAccessibility(announcement)
Post a string to be announced by the screen reader.
removeEventListener()
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static removeEventListener(eventName, handler)
Remove an event handler.