react-native/Libraries/Components/AccessibilityInfo/AccessibilityInfo.android.js

77 lines
1.9 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 AccessibilityInfo
* @flow
*/
'use strict';
var NativeModules = require('NativeModules');
var RCTDeviceEventEmitter = require('RCTDeviceEventEmitter');
var RCTAccessibilityInfo = NativeModules.AccessibilityInfo;
var TOUCH_EXPLORATION_EVENT = 'touchExplorationDidChange';
type ChangeEventName = $Enum<{
change: string,
}>;
var _subscriptions = new Map();
/**
* 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.
*
* See http://facebook.github.io/react-native/docs/accessibilityinfo.html
*/
var AccessibilityInfo = {
fetch: function(): Promise {
return new Promise((resolve, reject) => {
RCTAccessibilityInfo.isTouchExplorationEnabled(
function(resp) {
resolve(resp);
}
);
});
},
addEventListener: function (
eventName: ChangeEventName,
handler: Function
): void {
var listener = RCTDeviceEventEmitter.addListener(
TOUCH_EXPLORATION_EVENT,
(enabled) => {
handler(enabled);
}
);
_subscriptions.set(handler, listener);
},
removeEventListener: function(
eventName: ChangeEventName,
handler: Function
): void {
var listener = _subscriptions.get(handler);
if (!listener) {
return;
}
listener.remove();
_subscriptions.delete(handler);
},
};
module.exports = AccessibilityInfo;