| /* |
| * This class provides access to device accelerometer data. |
| * @constructor |
| */ |
| function Accelerometer() { |
| /* |
| * The last known acceleration. |
| */ |
| this.lastAcceleration = null; |
| }; |
| |
| /* |
| * Tells WebOS to put higher priority on accelerometer resolution. Also relaxes the internal garbage collection events. |
| * @param {Boolean} state |
| * Dependencies: Mojo.windowProperties |
| * Example: |
| * navigator.accelerometer.setFastAccelerometer(true) |
| */ |
| Accelerometer.prototype.setFastAccelerometer = function(state) { |
| navigator.windowProperties.fastAccelerometer = state; |
| navigator.window.setWindowProperties(); |
| }; |
| |
| /* |
| * Asynchronously aquires the current acceleration. |
| * @param {Function} successCallback The function to call when the acceleration |
| * data is available |
| * @param {Function} errorCallback The function to call when there is an error |
| * getting the acceleration data. |
| * @param {AccelerationOptions} options The options for getting the accelerometer data |
| * such as timeout. |
| */ |
| |
| Accelerometer.prototype.getCurrentAcceleration = function(successCallback, errorCallback, options) { |
| |
| var referenceTime = 0; |
| if (this.lastAcceleration) |
| referenceTime = this.lastAcceleration.timestamp; |
| else |
| this.start(); |
| |
| var timeout = 20000; |
| var interval = 500; |
| if (typeof(options) == 'object' && options.interval) |
| interval = options.interval; |
| |
| if (typeof(successCallback) != 'function') |
| successCallback = function() {}; |
| if (typeof(errorCallback) != 'function') |
| errorCallback = function() {}; |
| |
| var dis = this; |
| var delay = 0; |
| var timer = setInterval(function() { |
| delay += interval; |
| |
| //if we have a new acceleration, call success and cancel the timer |
| if (typeof(dis.lastAcceleration) == 'object' && dis.lastAcceleration != null && dis.lastAcceleration.timestamp > referenceTime) { |
| successCallback(dis.lastAcceleration); |
| clearInterval(timer); |
| } else if (delay >= timeout) { //else if timeout has occured then call error and cancel the timer |
| errorCallback(); |
| clearInterval(timer); |
| } |
| //else the interval gets called again |
| }, interval); |
| }; |
| |
| |
| /* |
| * Asynchronously aquires the acceleration repeatedly at a given interval. |
| * @param {Function} successCallback The function to call each time the acceleration |
| * data is available |
| * @param {Function} errorCallback The function to call when there is an error |
| * getting the acceleration data. |
| * @param {AccelerationOptions} options The options for getting the accelerometer data |
| * such as timeout. |
| */ |
| |
| Accelerometer.prototype.watchAcceleration = function(successCallback, errorCallback, options) { |
| this.getCurrentAcceleration(successCallback, errorCallback, options); |
| // TODO: add the interval id to a list so we can clear all watches |
| var frequency = (options != undefined)? options.frequency : 10000; |
| var that = this; |
| return setInterval(function() { |
| that.getCurrentAcceleration(successCallback, errorCallback, options); |
| }, frequency); |
| }; |
| |
| /* |
| * Clears the specified accelerometer watch. |
| * @param {String} watchId The ID of the watch returned from #watchAcceleration. |
| */ |
| Accelerometer.prototype.clearWatch = function(watchId) { |
| clearInterval(watchId); |
| }; |
| |
| /* |
| * Starts the native acceleration listener. |
| */ |
| |
| Accelerometer.prototype.start = function() { |
| var that = this; |
| //Mojo.Event.listen(document, "acceleration", function(event) { |
| document.addEventListener("acceleration", function(event) { |
| var accel = new Acceleration(event.accelX, event.accelY, event.accelZ); |
| that.lastAcceleration = accel; |
| }); |
| }; |
| |
| if (typeof navigator.accelerometer == "undefined") navigator.accelerometer = new Accelerometer(); |
| |