forked from github/cordova-android
97 lines
2.9 KiB
JavaScript
97 lines
2.9 KiB
JavaScript
/**
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* This class provides access to device Compass data.
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* @constructor
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*/
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function Compass() {
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/**
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* The last known Compass position.
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*/
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this.lastHeading = null;
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this.lastError = null;
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this.callbacks = {
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onHeadingChanged: [],
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onError: []
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};
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};
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/**
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* Asynchronously aquires the current heading.
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* @param {Function} successCallback The function to call when the heading
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* data is available
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* @param {Function} errorCallback The function to call when there is an error
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* getting the heading data.
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* @param {PositionOptions} options The options for getting the heading data
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* such as timeout.
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*/
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Compass.prototype.getCurrentHeading = function(successCallback, errorCallback, options) {
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if (this.lastHeading == null) {
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CompassHook.start();
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}
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else
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if (typeof successCallback == "function") {
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successCallback(this.lastHeading);
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}
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};
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/**
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* Asynchronously aquires the heading repeatedly at a given interval.
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* @param {Function} successCallback The function to call each time the heading
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* data is available
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* @param {Function} errorCallback The function to call when there is an error
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* getting the heading data.
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* @param {HeadingOptions} options The options for getting the heading data
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* such as timeout and the frequency of the watch.
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*/
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Compass.prototype.watchHeading= function(successCallback, errorCallback, options) {
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// Invoke the appropriate callback with a new Position object every time the implementation
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// determines that the position of the hosting device has changed.
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this.getCurrentHeading(successCallback, errorCallback, options);
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var frequency = 100;
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if (typeof(options) == 'object' && options.frequency)
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frequency = options.frequency;
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var self = this;
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return setInterval(function() {
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self.getCurrentHeading(successCallback, errorCallback, options);
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}, frequency);
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};
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/**
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* Clears the specified heading watch.
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* @param {String} watchId The ID of the watch returned from #watchHeading.
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*/
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Compass.prototype.clearWatch = function(watchId) {
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clearInterval(watchId);
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};
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/**
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* Called by the geolocation framework when the current heading is found.
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* @param {HeadingOptions} position The current heading.
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*/
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Compass.prototype.setHeading = function(heading) {
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this.lastHeading = heading;
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for (var i = 0; i < this.callbacks.onHeadingChanged.length; i++) {
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var f = this.callbacks.onHeadingChanged.shift();
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f(heading);
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}
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};
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/**
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* Called by the geolocation framework when an error occurs while looking up the current position.
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* @param {String} message The text of the error message.
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*/
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Compass.prototype.setError = function(message) {
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this.lastError = message;
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for (var i = 0; i < this.callbacks.onError.length; i++) {
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var f = this.callbacks.onError.shift();
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f(message);
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}
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};
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PhoneGap.addConstructor(function() {
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if (typeof navigator.compass == "undefined") navigator.compass = new Compass();
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});
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