CaptureController: setFocusBehavior() method
Limited availability
This feature is not Baseline because it does not work in some of the most widely-used browsers.
Experimental: This is an experimental technology
Check the Browser compatibility table carefully before using this in production.
Secure context: This feature is available only in secure contexts (HTTPS), in some or all supporting browsers.
The CaptureController interface's setFocusBehavior() method controls whether the captured tab or window will be focused when an associated MediaDevices.getDisplayMedia() Promise fulfills, or whether the focus will remain with the tab containing the capturing app.
You can set this behavior multiple times before the MediaDevices.getDisplayMedia() call, or once immediately after its Promise resolves. After that, the focus behavior is said to be finalized, and can't be changed.
Syntax
setFocusBehavior(focusBehavior)
Parameters
focusBehavior-
An enumerated value that describes whether the user agent should transfer focus to the captured display surface, or keep the capturing app focused. Possible values are
focus-captured-surface(transfer focus) andno-focus-change(keep focus on the capturing app).
Return value
None (undefined).
Exceptions
InvalidStateErrorDOMException-
Thrown if:
- The capture stream has been stopped.
- The user chose to share a screen (
displaySurfacetypemonitor) rather than abrowsertab orwindow— you can't focus a monitor. In this case the exception is thrown after theMediaDevices.getDisplayMedia()Promiseresolves. - Enough time has elapsed after the
MediaDevices.getDisplayMedia()Promisefulfills that the focus behavior has been finalized.
Examples
Basic setFocusBehavior() usage
// Create a new CaptureController instance
const controller = new CaptureController();
// Prompt the user to share a tab, window, or screen.
const stream = await navigator.mediaDevices.getDisplayMedia({ controller });
// Query the displaySurface value of the captured video track
const [track] = stream.getVideoTracks();
const displaySurface = track.getSettings().displaySurface;
if (displaySurface === "browser") {
// Focus the captured tab.
controller.setFocusBehavior("focus-captured-surface");
} else if (displaySurface === "window") {
// Do not move focus to the captured window.
// Keep the capturing page focused.
controller.setFocusBehavior("no-focus-change");
}
Specifications
| Specification |
|---|
| Screen Capture # dom-capturecontroller-setfocusbehavior |
Browser compatibility
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