This is an experimental technology
Because this technology's specification has not stabilized, check the compatibility table for usage in various browsers. Also note that the syntax and behavior of an experimental technology is subject to change in future versions of browsers as the specification changes.
The proximity events are a handy way to know when a user is close to a device. These events make it possible to react to such a change, for example by shutting down the screen of a smartphone when the user is having a phone call with the device close to their ear.
Note: Obviously, the API requires the device to have a proximity sensor, which are mostly available only on mobile devices. Devices without such a sensor may support those events but will never fire them.
Proximity Events
When the device proximity sensor detects a change between the device and an object, it notifies the browser of that change. When the browser gets such a notification, it fires a DeviceProximityEvent
for any change, and a UserProximityEvent
event in the case of a more rough change.
This event can be captured at the window
object level by using the addEventListener
method (using the deviceproximity
or userproximity
event name) or by attaching an event handler to the window.ondeviceproximity
or window.onuserproximity
properties.
Once captured, the event object gives access to different kinds of information:
- The
DeviceProximityEvent
event provides an exact match for the distance between the device and the object through itsvalue
property. It also provides the closest and farthest distance the device is able to detect something through itsmin
andmax
properties. - The
UserProximityEvent
event provides a rough approximation of the distance, expressed through a boolean. TheUserProximityEvent.near
property istrue
if the object is close orfalse
if the object is far.
Example
window.addEventListener('userproximity', function(event) { if (event.near) { // let's power off the screen navigator.mozPower.screenEnabled = false; } else { // Otherwise, let's power on the screen navigator.mozPower.screenEnabled = true; } });
Specifications
Specification | Status | Comment |
---|---|---|
Proximity Events The definition of 'Proximity Events' in that specification. |
Working Draft | Initial specification |
Browser compatibility
Feature | Chrome | Firefox (Gecko) | Internet Explorer | Opera | Safari |
---|---|---|---|---|---|
DeviceProximityEvent |
No support | (Yes) | No support | No support | No support |
UserProximityEvent |
No support | (Yes) | No support | No support | No support |
Feature | Android | Chrome for Android | Firefox Mobile (Gecko) | IE Mobile | Opera Mobile | Safari Mobile |
---|---|---|---|---|---|---|
DeviceProximityEvent |
No support | No support | 15.0 (15.0) | No support | No support | No support |
UserProximityEvent |
No support | No support | (Yes) | No support | No support | No support |