react-native/Libraries/CustomComponents/Navigator/Navigation/NavigationContext.js

97 lines
3.2 KiB
JavaScript

/**
* Copyright (c) 2015, Facebook, Inc. All rights reserved.
*
* Facebook, Inc. (“Facebook”) owns all right, title and interest, including
* all intellectual property and other proprietary rights, in and to the React
* Native CustomComponents software (the “Software”). Subject to your
* compliance with these terms, you are hereby granted a non-exclusive,
* worldwide, royalty-free copyright license to (1) use and copy the Software;
* and (2) reproduce and distribute the Software as part of your own software
* (“Your Software”). Facebook reserves all rights not expressly granted to
* you in this license agreement.
*
* THE SOFTWARE AND DOCUMENTATION, IF ANY, ARE PROVIDED "AS IS" AND ANY EXPRESS
* OR IMPLIED WARRANTIES (INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE) ARE DISCLAIMED.
* IN NO EVENT SHALL FACEBOOK OR ITS AFFILIATES, OFFICERS, DIRECTORS OR
* EMPLOYEES BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
* OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
* OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THE SOFTWARE, EVEN IF
* ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* @providesModule NavigationContext
*/
'use strict';
var NavigationEventEmitter = require('NavigationEventEmitter');
var emptyFunction = require('emptyFunction');
var invariant = require('invariant');
import type * as NavigationEvent from 'NavigationEvent';
import type * as EventSubscription from 'EventSubscription';
/**
* Class that contains the info and methods for app navigation.
*/
class NavigationContext {
_eventEmitter: ?NavigationEventEmitter;
_currentRoute: any;
constructor() {
this._eventEmitter = new NavigationEventEmitter(this);
this._currentRoute = null;
this.addListener('willfocus', this._onFocus, this);
this.addListener('didfocus', this._onFocus, this);
}
// TODO: @flow does not like this getter. Will add @flow check back once
// getter/setter is supported.
get currentRoute(): any {
return this._currentRoute;
}
addListener(
eventType: string,
listener: Function,
context: ?Object
): EventSubscription {
var emitter = this._eventEmitter;
if (emitter) {
return emitter.addListener(eventType, listener, context);
} else {
return {remove: emptyFunction};
}
}
emit(eventType: String, data: any): void {
var emitter = this._eventEmitter;
if (emitter) {
emitter.emit(eventType, data);
}
}
dispose(): void {
var emitter = this._eventEmitter;
if (emitter) {
// clean up everything.
emitter.removeAllListeners();
this._eventEmitter = null;
this._currentRoute = null;
}
}
_onFocus(event: NavigationEvent): void {
invariant(
event.data && event.data.hasOwnProperty('route'),
'didfocus event should provide route'
);
this._currentRoute = event.data.route;
}
}
module.exports = NavigationContext;