# Titanium.Accelerometer

The top-level Accelerometer module, used to determine the device's physical position.

Availability
0.8
0.8
9.2.0
4.1.0

# Overview

An accelerometer is a hardware unit integrated into a mobile device, that detects when the device has moved, and returns its new orientation in a three-dimensional space. With its single update event, this module provides an interface to access the output positional data.

An accelerometer needs to be switched on in order for it to report to the operating system, which consumes a lot of power that will deplete the battery over time. This is why it is recommended that the accelerometer is switched off when not in use.

The accelerometer may be switched on and off by simply adding and removing the update event listener function. See the example for a demonstration.

# Examples

# Basic Accelerometer Event

Adds an accelerometer update event listener, and displays the x, y and z axis in the window when the device is moved. On Android, the accelerometer is switched off and on when the application is paused and resumed.

var win = Ti.UI.createWindow({
  backgroundColor: 'white',
  exitOnClose:true,
  layout: 'vertical'
});

opts = {
  color:'black',
  font:{fontSize:20},
  text:'-',
  top:20, left:10,
  width:300
};
var labelTimestamp = Ti.UI.createLabel(opts);
win.add(labelTimestamp);
var labelx = Ti.UI.createLabel(opts);
win.add(labelx);
var labely = Ti.UI.createLabel(opts);
win.add(labely);
var labelz = Ti.UI.createLabel(opts);
win.add(labelz);
win.open();

var accelerometerCallback = function(e) {
  labelTimestamp.text = 'timestamp: ' + e.timestamp;
  labelx.text = 'x: ' + e.x;
  labely.text = 'y: ' + e.y;
  labelz.text = 'z: ' + e.z;
};

if (Ti.Platform.model === 'Simulator' || Ti.Platform.model.indexOf('sdk') !== -1 ) {
  alert('Accelerometer does not work on a virtual device');
} else {
  Ti.Accelerometer.addEventListener('update', accelerometerCallback);
  if (Ti.Platform.name === 'android') {
    win.addEventListener("open", function(e) {
      win.activity.addEventListener("pause", function() {
        Ti.API.info("removing accelerometer callback on pause");
        Ti.Accelerometer.removeEventListener('update', accelerometerCallback);
      });
      win.activity.addEventListener("resume", function() {
        Ti.API.info("adding accelerometer callback on resume");
        Ti.Accelerometer.addEventListener('update', accelerometerCallback);
      });
    });
  }
}

# Events

# update

Availability
0.8
0.8
9.2.0
4.1.0

Fired when the accelerometer changes.

Properties

Name Type Description
timestamp Number

Reference timestamp since the previous change. This is not a valid timestamp and should simply be used to determine the number of milliseconds between events.

y Number

Current y axis of the device.

x Number

Current x axis of the device.

z Number

Current z axis of the device.

bubbles Boolean

True if the event will try to bubble up if possible.

cancelBubble Boolean

Set to true to stop the event from bubbling.

source Object

Source object that fired the event.

type String

Name of the event fired.