openmct/platform/commonUI/browse/src/navigation/NavigationService.js

89 lines
3.2 KiB
JavaScript

/*****************************************************************************
* Open MCT, Copyright (c) 2014-2016, United States Government
* as represented by the Administrator of the National Aeronautics and Space
* Administration. All rights reserved.
*
* Open MCT is licensed under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
* http://www.apache.org/licenses/LICENSE-2.0.
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
* Open MCT includes source code licensed under additional open source
* licenses. See the Open Source Licenses file (LICENSES.md) included with
* this source code distribution or the Licensing information page available
* at runtime from the About dialog for additional information.
*****************************************************************************/
/**
* Module defining NavigationService. Created by vwoeltje on 11/10/14.
*/
define(
[],
function () {
/**
* The navigation service maintains the application's current
* navigation state, and allows listening for changes thereto.
* @memberof platform/commonUI/browse
* @constructor
*/
function NavigationService() {
this.navigated = undefined;
this.callbacks = [];
}
/**
* Get the current navigation state.
* @returns {DomainObject} the object that is navigated-to
*/
NavigationService.prototype.getNavigation = function () {
return this.navigated;
};
/**
* Set the current navigation state. This will invoke listeners.
* @param {DomainObject} domainObject the domain object to navigate to
*/
NavigationService.prototype.setNavigation = function (value) {
if (this.navigated !== value) {
this.navigated = value;
this.callbacks.forEach(function (callback) {
callback(value);
});
}
return true;
};
/**
* Listen for changes in navigation. The passed callback will
* be invoked with the new domain object of navigation when
* this changes.
* @param {function} callback the callback to invoke when
* navigation state changes
*/
NavigationService.prototype.addListener = function (callback) {
this.callbacks.push(callback);
};
/**
* Stop listening for changes in navigation state.
* @param {function} callback the callback which should
* no longer be invoked when navigation state
* changes
*/
NavigationService.prototype.removeListener = function (callback) {
this.callbacks = this.callbacks.filter(function (cb) {
return cb !== callback;
});
};
return NavigationService;
}
);