W3cubDocs

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 — The VRDisplay has detected that the user has put it on (or it has been otherwise activated).
navigation — 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 — The user agent has requested that VR presentation mode be started. This allows user agents to include a consistent UI to enter VR across diferent sites.
unmounted — 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) {
  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 compatibilityUpdate compatibility data on GitHub

	Desktop
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari
Basic support	No	15	55 55 Windows support was enabled in Firefox 55. 63 macOS support was enabled in Firefox 63.	No	?	?

	Mobile
	Android webview	Chrome for Android	Edge Mobile	Firefox for Android	Opera for Android	iOS Safari	Samsung Internet
Basic support	No	56 Disabled 56 Disabled Only works in an experimental version of Chrome. (Other builds won't return any devices when `Navigator.getVRDisplays()` is invoked.) Daydream View supported in Chrome 56. 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.	?	?	?	?	6.0

VRDisplayEvent.reason

Syntax

Value

Examples

Specifications

Browser compatibilityUpdate compatibility data on GitHub

See also