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 increaseZoomLevel()
method increases the captured display surface's zoom level by one increment.
The increaseZoomLevel()
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.
None.
Return valueA Promise
that fulfills with undefined
.
InvalidStateError
DOMException
Thrown when:
increaseZoomLevel()
without transient activation.NotAllowedError
DOMException
Thrown when:
captured-surface-control
Permissions Policy does not permit the page to use the Captured Surface Control API.increaseZoomLevel()
usage
The following snippet adds an event listener to a button so that when it is clicked, the increaseZoom()
function is called. This in turn calls the increaseZoomLevel()
method, zooming the captured surface in.
// Create controller and start capture
const controller = new CaptureController();
videoElem.srcObject = await navigator.mediaDevices.getDisplayMedia({
controller,
});
// ...
incBtn.addEventListener("click", increaseZoom);
async function increaseZoom() {
try {
await controller.increaseZoomLevel();
} catch (e) {
console.log(e);
}
}
It is generally a best practice to call increaseZoomLevel()
from within a try...catch
block because the zoom level could be changed asynchronously by an entity other than the application, which might lead to an error being thrown. For example, the user might directly interact with the captured surface to zoom in or out.
See Using the Captured Surface Control API for a full working example.
Specifications Browser compatibility See alsoRetroSearch is an open source project built by @garambo | Open a GitHub Issue
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HTML:
3.2
| Encoding:
UTF-8
| Version:
0.7.4