VRDisplayEvent.reason

This is an experimental technology
Check the Browser compatibility table carefully before using this in production.

The reason read-only property of the VRDisplayEvent interface returns a human-readable reason why the event was fired.

Syntax

var myReason = vrDisplayEventInstance.reason;

Value

A string representing the reason why the event was fired. The available reasons are defined in the VRDisplayEventReason enum, and are as follows:

  • mounted ā€” The VRDisplay has detected that the user has put it on (or it has been otherwise activated).
  • navigation ā€” The page has been navigated to from a context that allows this page to begin presenting immediately, such as from another site that was already in VR presentation mode.
  • requested ā€” The user agent has requested that VR presentation mode be started. This allows user agents to include a consistent UI to enter VR across different sites.
  • unmounted ā€” The VRDisplay has detected that the user has taken it off (or it has been otherwise slept/put on standby).

Examples

window.addEventListener('vrdisplaypresentchange', function(e) {
Ā  console.log('Display ' + e.display.displayId + ' presentation has changed. Reason given: ' + e.reason + '.');
})

Specifications

Specification Status Comment
WebVR 1.1
The definition of 'reason' in that specification.
Draft Initial definition

Browser compatibility

Update compatibility data on GitHub
DesktopMobile
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidFirefox for AndroidOpera for AndroidSafari on iOSSamsung Internet
reason
ExperimentalDeprecated
Chrome No support NoEdge Full support 15Firefox Full support 55
Notes
Full support 55
Notes
Notes Windows support was enabled in Firefox 55.
Full support 64
Notes
Notes macOS support was enabled in Firefox 64.
IE No support NoOpera ? Safari ? WebView Android No support NoChrome Android Full support 56
Notes Disabled
Full support 56
Notes Disabled
Notes Only works in an experimental version of Chrome. (Other builds won't return any devices when Navigator.getVRDisplays() is invoked.)
Notes Daydream View supported in Chrome 56.
Notes Google Cardboard supported in Chrome 57.
Disabled From version 56: this feature is behind the WebVR preference. To change preferences in Chrome, visit chrome://flags.
Firefox Android Full support 55Opera Android ? Safari iOS ? Samsung Internet Android Full support 6.0

Legend

Full support Ā 
Full support
No support Ā 
No support
Compatibility unknown Ā 
Compatibility unknown
Experimental. Expect behavior to change in the future.
Experimental. Expect behavior to change in the future.
Deprecated. Not for use in new websites.
Deprecated. Not for use in new websites.
See implementation notes.
See implementation notes.
User must explicitly enable this feature.
User must explicitly enable this feature.

See also