files/en-us/web/api/mediatracksupportedconstraints/displaysurface/index.md
{{APIRef("Media Capture and Streams")}}
The {{domxref("MediaTrackSupportedConstraints")}} dictionary's displaySurface property indicates whether or not the {{domxref("MediaTrackConstraints.displaySurface", "displaySurface")}} 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()")}}.
A Boolean value which is true if the {{domxref("MediaTrackConstraints.displaySurface", "displaySurface")}} constraint is supported by the device and user agent.
This method sets up the constraints object specifying the options for the call to
{{domxref("MediaDevices.getDisplayMedia", "getDisplayMedia()")}}. It adds the
displaySurface constraint (requesting that only fullscreen sharing be
allowed) 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.
async function capture() {
let supportedConstraints = navigator.mediaDevices.getSupportedConstraints();
let displayMediaOptions = {
video: {},
audio: false,
};
if (supportedConstraints.displaySurface) {
displayMediaOptions.video.displaySurface = "monitor";
}
try {
videoElem.srcObject =
await navigator.mediaDevices.getDisplayMedia(displayMediaOptions);
} catch (err) {
/* handle the error */
}
}
{{Specifications}}
{{Compat}}