Skip to main content

Proximity

The proximity sensor is a sensor that lets you determine how close the face of a device is to an object (known as the proximity sensor). Most commonly this is used to detect if the user is holding the device to their face (eg during a phone call) so that the device can deactivate the screen and controls.

The proximity sensor is accessed through the proximity property on the SensorManager singleton:

SensorManager.service.proximity

This object dispatches events and provides the interface for you to access the proximity sensor.

Monitoring Proximity​

In order to start monitoring proximity you need to call startMonitoring(). This function will initiate proximity detection.

SensorManager.service.proximity.startMonitoring();

After this has been called ProximityEvent.CHANGED events will be dispatched whenever the proximity state changes.

SensorManager.service.proximity.addEventListener( ProximityEvent.CHANGED, proximity_changedHandler );


function proximity_changedHandler( event:ProximityEvent ):void
{
    trace( "proximity changed: " + event.state );
}

You can also directly access the current state at any time using the proximityState property:

var state:String = SensorManager.service.proximity.proximityState;

The values of the proximity state are definded in the ProximityState class:

  • ProximityState.UNKNOWN: The state has yet to be determined or is unavailable;
  • ProximityState.NEAR: The user is near to the device;
  • ProximityState.FAR: The user is far from the device;
caution

On iOS the screen will be automatically dimmed when the proximity sensor is enabled and the proximity state is determined to be "near" (close to the user).

Stop Monitoring​

To stop proximity monitoring you call the stopMonitoring() function.

SensorManager.service.proximity.startMonitoring();

After calling this the proximity state will be invalid.

You should also remove any proximity event listeners you may have added.

SensorManager.service.proximity.removeEventListener( ProximityEvent.CHANGED, proximity_changedHandler );