react-native/Libraries/Utilities/SceneTracker.js
Sophie Alpert 1490ab12ef Update license headers for MIT license
Summary:
Includes React Native and its dependencies Fresco, Metro, and Yoga. Excludes samples/examples/docs.

find: ^(?:( *)|( *(?:[\*~#]|::))( )? *)?Copyright (?:\(c\) )?(\d{4})\b.+Facebook[\s\S]+?BSD[\s\S]+?(?:this source tree|the same directory)\.$
replace: $1$2$3Copyright (c) $4-present, Facebook, Inc.\n$2\n$1$2$3This source code is licensed under the MIT license found in the\n$1$2$3LICENSE file in the root directory of this source tree.

Reviewed By: TheSavior, yungsters

Differential Revision: D7007050

fbshipit-source-id: 37dd6bf0ffec0923bfc99c260bb330683f35553e
2018-02-16 18:31:53 -08:00

40 lines
863 B
JavaScript

/**
* Copyright (c) 2015-present, Facebook, Inc.
*
* This source code is licensed under the MIT license found in the
* LICENSE file in the root directory of this source tree.
*
* @providesModule SceneTracker
* @flow
*/
'use strict';
type Scene = {name: string};
let _listeners: Array<(scene: Scene) => void> = [];
let _activeScene = {name: 'default'};
const SceneTracker = {
setActiveScene(scene: Scene) {
_activeScene = scene;
_listeners.forEach((listener) => listener(_activeScene));
},
getActiveScene(): Scene {
return _activeScene;
},
addActiveSceneChangedListener(callback: (scene: Scene) => void): {remove: () => void} {
_listeners.push(callback);
return {
remove: () => {
_listeners = _listeners.filter((listener) => callback !== listener);
},
};
},
};
module.exports = SceneTracker;