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MediaTrackSupportedConstraints: logicalSurface property

files/en-us/web/api/mediatracksupportedconstraints/logicalsurface/index.md

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{{APIRef("Media Capture and Streams")}}

The {{domxref("MediaTrackSupportedConstraints")}} dictionary's logicalSurface property indicates whether or not the {{domxref("MediaTrackConstraints.logicalSurface", "logicalSurface")}} constraint is supported by the user agent and the device on which the content is being used.

The supported constraints list is obtained by calling {{domxref("MediaDevices.getSupportedConstraints","navigator.mediaDevices.getSupportedConstraints()")}}.

Value

A boolean value which is true if the {{domxref("MediaTrackConstraints.logicalSurface", "logicalSurface")}} constraint is supported by the device and user agent.

Example

This method sets up the constraints object specifying the options for the call to {{domxref("MediaDevices.getDisplayMedia", "getDisplayMedia()")}}. It adds the logicalSurface constraint (requesting that only logical display surfaces—those which may not be entirely visible onscreen—be included among the options available to the user) only if it is known to be supported by the browser. Capturing is then started by calling getDisplayMedia() and attaching the returned stream to the video element referenced by the variable videoElem.

js
async function capture() {
  const supportedConstraints = navigator.mediaDevices.getSupportedConstraints();
  const displayMediaOptions = {
    video: {},
    audio: false,
  };

  if (supportedConstraints.logicalSurface) {
    displayMediaOptions.video.logicalSurface = "monitor";
  }

  try {
    videoElem.srcObject =
      await navigator.mediaDevices.getDisplayMedia(displayMediaOptions);
  } catch (err) {
    /* handle the error */
  }
}

Specifications

{{Specifications}}

Browser compatibility

{{Compat}}

See also