# Titanium.Accelerometer

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

Availability

0.8

9.2.0

Extends

Titanium.Module

# 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);
      });
    });
  }
}

# Properties

# apiName READONLY

Availability

3.2.0

9.2.0

apiName :String

The name of the API that this proxy corresponds to.

The value of this property is the fully qualified name of the API. For example, Titanium.UI.Button returns Ti.UI.Button.

# bubbleParent

Availability

3.0.0

9.2.0

bubbleParent :Boolean

Indicates if the proxy will bubble an event to its parent.

Some proxies (most commonly views) have a relationship to other proxies, often established by the add() method. For example, for a button added to a window, a click event on the button would bubble up to the window. Other common parents are table sections to their rows, table views to their sections, and scrollable views to their views. Set this property to false to disable the bubbling to the proxy's parent.

Default: true

# lifecycleContainer

Availability

3.6.0

lifecycleContainer :Titanium.UI.Window | Titanium.UI.TabGroup

The Window or TabGroup whose Activity lifecycle should be triggered on the proxy.

If this property is set to a Window or TabGroup, then the corresponding Activity lifecycle event callbacks will also be called on the proxy. Proxies that require the activity lifecycle will need this property set to the appropriate containing Window or TabGroup.

# Methods

# addEventListener

Availability

0.8

9.2.0

addEventListener(name, callback) → void

Adds the specified callback as an event listener for the named event.

Parameters

Name	Type	Description
`name`	String	Name of the event.
`callback`	Callback<Titanium.Event>	Callback function to invoke when the event is fired.

Returns

Type: void

# applyProperties

Availability

3.0.0

9.2.0

applyProperties(props) → void

Applies the properties to the proxy.

Properties are supplied as a dictionary. Each key-value pair in the object is applied to the proxy such that myproxy[key] = value.

Parameters

Name	Type	Description
`props`	Dictionary	A dictionary of properties to apply.

Returns

Type: void

# fireEvent

Availability

0.8

9.2.0

fireEvent(name[, event]) → void

Fires a synthesized event to any registered listeners.

Parameters

Name	Type	Description
`name`	String	Name of the event.
`event`	Dictionary	A dictionary of keys and values to add to the Titanium.Event object sent to the listeners.

Returns

Type: void

# removeEventListener

Availability

0.8

9.2.0

removeEventListener(name, callback) → void

Removes the specified callback as an event listener for the named event.

Multiple listeners can be registered for the same event, so the callback parameter is used to determine which listener to remove.

When adding a listener, you must save a reference to the callback function in order to remove the listener later:

var listener = function() { Ti.API.info("Event listener called."); }
window.addEventListener('click', listener);

To remove the listener, pass in a reference to the callback function:

window.removeEventListener('click', listener);

Parameters

Name	Type	Description
`name`	String	Name of the event.
`callback`	Callback<Titanium.Event>	Callback function to remove. Must be the same function passed to `addEventListener`.

Returns

Type: void

# Events

# update

Availability

0.8

9.2.0

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.
source	Object	Source object that fired the event.
type	String	Name of the event fired.
bubbles	Boolean	True if the event will try to bubble up if possible.
cancelBubble	Boolean	Set to true to stop the event from bubbling.