CaptureController: setFocusBehavior() method

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) and no-focus-change (keep focus on the capturing app).

Return value

None (undefined).

Exceptions

InvalidStateError DOMException

Thrown if:

The capture stream has been stopped.
The user chose to share a screen (displaySurface type monitor) rather than a browser tab or window — you can't focus a monitor. In this case the exception is thrown after the MediaDevices.getDisplayMedia() Promise resolves.
Enough time has elapsed after the MediaDevices.getDisplayMedia() Promise fulfills that the focus behavior has been finalized.

Examples

undefined

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

Screen Capture