CaptureController: resetZoomLevel() method

The CaptureController interface's resetZoomLevel() method resets the captured display surface's zoom to its initial level, which is 100.

The resetZoomLevel() method must be invoked via transient activation. In addition, the user is asked for permission to share tabs when screen capture is first attempted; if the user denies permission the zoom level cannot be changed even with transient activation.

Syntax

resetZoomLevel()

Parameters

None.

Return value

A Promise that fulfills with undefined.

Exceptions

InvalidStateError DOMException

An attempt is made to invoke resetZoomLevel() without transient activation.

NotAllowedError DOMException

Thrown when:

• The page's captured-surface-control Permissions Policy does not permit the page to use the Captured Surface Control API.
• Permission to capture the display surface is explicitly denied by the user.

Examples

Basic resetZoomLevel() usage

The following snippet adds an event listener to a button so that when it is clicked, the resetZoom() function is called. This in turn calls the resetZoomLevel() method, resetting the captured surface's zoom level to 100.

// Create controller and start capture
const controller = new CaptureController();
videoElem.srcObject = await navigator.mediaDevices.getDisplayMedia({
  controller,
});

// ...

resetBtn.addEventListener("click", resetZoom);

async function resetZoom() {
  await controller.resetZoomLevel();
}

See Using the Captured Surface Control API for a full working example.

Specifications

Browser compatibility

See also

• Screen Capture API
• MediaDevices.getDisplayMedia()
• Using the Captured Surface Control API