react-native/docs/accessibilityinfo.md
Héctor Ramos e11d496e9d Additional markdown adjustments
Summary:
Follow up to 9ec95673909beac7798f589e0e9821b4225f8fa9
Closes https://github.com/facebook/react-native/pull/16759

Differential Revision: D6285219

Pulled By: hramos

fbshipit-source-id: 7012d257a5a6cff06cb2d94203a9379e4b7e3c4e
2017-11-09 09:55:05 -08:00

3.1 KiB

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accessibilityinfo AccessibilityInfo docs APIs docs/accessibilityinfo.html actionsheetios webview

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 ScreenReaderStatusExample extends React.Component {
  state = {
    screenReaderEnabled: false,
  }

  componentDidMount() {
    AccessibilityInfo.addEventListener(
      'change',
      this._handleScreenReaderToggled
    );
    AccessibilityInfo.fetch().done((isEnabled) => {
      this.setState({
        screenReaderEnabled: isEnabled
      });
    });
  }

  componentWillUnmount() {
    AccessibilityInfo.removeEventListener(
      'change',
      this._handleScreenReaderToggled
    );
  }

  _handleScreenReaderToggled = (isEnabled) => {
    this.setState({
      screenReaderEnabled: isEnabled,
    });
  }

  render() {
    return (
      <View>
        <Text>
          The screen reader is {this.state.screenReaderEnabled ? 'enabled' : 'disabled'}.
        </Text>
      </View>
    );
  }
}

Methods


Reference

Methods

fetch()

AccessibilityInfo.fetch()

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()

AccessibilityInfo.addEventListener(eventName, handler)

Add an event handler. Supported events:

  • change: Fires when the state of the screen reader changes. The argument to the event handler is a boolean. The boolean is true when a screen reader is enabled and false 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()

AccessibilityInfo.setAccessibilityFocus(reactTag)

iOS-Only. Set accessibility focus to a react component.


announceForAccessibility()

AccessibilityInfo.announceForAccessibility(announcement)

iOS-Only. Post a string to be announced by the screen reader.


removeEventListener()

AccessibilityInfo.removeEventListener(eventName, handler)

Remove an event handler.