MediaTrackConstraints: logicalSurface property
The MediaTrackConstraints
dictionary's logicalSurface
property is a ConstrainDOMString
describing the requested or mandatory constraints placed upon the value of the logicalSurface
constrainable property.
This is used to specify whether or
not getDisplayMedia()
should allow the
user to choose display surfaces which are not necessarily fully visible on the screen,
such as occluded windows or the complete content of windows which are large enough to
require scrolling to see their entire contents.
If needed, you can determine whether or not this constraint is supported by checking
the value of MediaTrackSupportedConstraints.logicalSurface
as returned by
a call to MediaDevices.getSupportedConstraints()
. However, typically this
is unnecessary since browsers will ignore any constraints they're unfamiliar with.
Value
A ConstrainBoolean
which is true
if logical surfaces should be permitted among the selections available to the user.
Usage notes
You can check the setting selected by the user agent after the display media has been
created by getDisplayMedia()
by calling
getSettings()
on the display media's
video MediaStreamTrack
, then checking the value of the returned
MediaTrackSettings
object's
logicalSurface
object.
For example, if your app needs to know if the selected display surface is a logical one:
js
let isLogicalSurface = displayStream
.getVideoTracks()[0]
.getSettings().logicalSurface;
Following this code, isLogicalSurface
is true
if the display
surface contained in the stream is a logical surface; that is, one which may not be
entirely onscreen, or may even be entirely offscreen.
Specifications
Specification |
---|
Screen Capture # dom-mediatrackconstraintset-logicalsurface |
Browser compatibility
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