framework/js/accelerometer.js

/*
 * PhoneGap is available under *either* the terms of the modified BSD license *or* the
 * MIT License (2008). See http://opensource.org/licenses/alphabetical for full text.
 *
 * Copyright (c) 2005-2011, Nitobi Software Inc.
 * Copyright (c) 2010-2011, IBM Corporation
 * Copyright (c) 2011, Microsoft Corporation
 */

if (!PhoneGap.hasResource("accelerometer")) 
{
PhoneGap.addResource("accelerometer");

/** @constructor */
var Acceleration = function(x, y, z) {
  this.x = x;
  this.y = y;
  this.z = z;
  this.timestamp = new Date().getTime();
};

/**
 * This class provides access to device accelerometer data.
 * @constructor
 */
var Accelerometer = function() {

    /**
     * The last known acceleration.  type=Acceleration()
     */
    this.lastAcceleration = null;

    /**
     * List of accelerometer watch timers
     */
    this.timers = {};
};

Accelerometer.ERROR_MSG = ["Not running", "Starting", "", "Failed to start"];

/**
 * 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. (OPTIONAL)
 * @param {AccelerationOptions} options The options for getting the accelerometer data such as timeout. (OPTIONAL)
 */
Accelerometer.prototype.getCurrentAcceleration = function(successCallback, errorCallback, options) {

    // successCallback required
    if (typeof successCallback !== "function") {
        console.log("Accelerometer Error: successCallback is not a function");
        return;
    }

    // errorCallback optional
    if (errorCallback && (typeof errorCallback !== "function")) {
        console.log("Accelerometer Error: errorCallback is not a function");
        return;
    }
	
	var self = this;
	
	var onSuccess = function(result)
	{
		var accResult = JSON.parse(result);
		console.log("Accel x = " + accResult.x);
		self.lastAcceleration = new Acceleration(accResult.x,accResult.y,accResult.z);
		successCallback(self.lastAcceleration);
	}
	
	var onError = function(err)
	{
		errorCallback(err);
	}

    // Get acceleration
    PhoneGap.exec(onSuccess, onError, "Accelerometer", "getAcceleration",options);
};


/**
 * 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. (OPTIONAL)
 * @param {AccelerationOptions} options The options for getting the accelerometer data such as timeout. (OPTIONAL)
 * @return String                       The watch id that must be passed to #clearWatch to stop watching.
 */
Accelerometer.prototype.watchAcceleration = function(successCallback, errorCallback, options) 
{

    // successCallback required
    if (typeof successCallback !== "function") {
        console.log("Accelerometer Error: successCallback is not a function");
        return;
    }

    // errorCallback optional
    if (errorCallback && (typeof errorCallback !== "function")) {
        console.log("Accelerometer Error: errorCallback is not a function");
        return;
    }
	
    var onSuccess = function (result) {
        var accResult = JSON.parse(result);
        console.log("Accel x = " + accResult.x);
        self.lastAcceleration = new Acceleration(accResult.x, accResult.y, accResult.z);
        successCallback(self.lastAcceleration);
    }

    var onError = function (err) {
        errorCallback(err);
    }

    var id = PhoneGap.createUUID();

    var params = new Object();
    params.id = id;
    // Default interval (10 sec)
    params.frequency = (options && options.frequency) ? options.frequency : 10000;

    PhoneGap.exec(onSuccess, onError, "Accelerometer", "startWatch", params);

    return id; 
};

/**
 * Clears the specified accelerometer watch.
 *
 * @param {String} id       The id of the watch returned from #watchAcceleration.
 */
Accelerometer.prototype.clearWatch = function(id) {

    PhoneGap.exec(null, null, "Accelerometer", "stopWatch", { id: id });
};

PhoneGap.addConstructor(
function()
{
    if (!navigator.accelerometer) 
	{
		console.log("Installing accelerometer");
        navigator.accelerometer = new Accelerometer();
    }
});
}