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 forwardWheel()
method starts forwarding wheel
events fired on the referenced element to the viewport of an associated captured display surface.
The forwardWheel()
method must be invoked via transient activation. Specifically, the only events that can successfully invoke it are click
and input
. In addition, the user is asked for permission to share tabs when screen capture is first attempted; if the user grants permission, this also includes permission to scroll captured tabs. If the relevant permission is already "granted"
, transient activation is not needed.
element
A reference to the element whose wheel
events you want to forward to the associated captured display surface.
A Promise
that fulfills with undefined
.
InvalidStateError
DOMException
Thrown when:
MediaStream
returned by the originating MediaDevices.getDisplayMedia()
call is no longer capturing, for example because the associated MediaStreamTrack
objects have had stop()
called on them.forwardWheel()
without transient activation, when permission to use it has not been granted by the user.NotAllowedError
DOMException
Thrown when:
captured-surface-control
Permissions Policy does not permit the page to use the Captured Surface Control API.NotSupportedError
DOMException
The surface type being captured is not a browser tab.
forwardWheel()
usage
In our live demo, explained in Using the Captured Surface Control API, we call a function called startForwarding()
after the capturing getDisplayMedia()
promise fulfills:
// Create controller and start capture
const controller = new CaptureController();
videoElem.srcObject = await navigator.mediaDevices.getDisplayMedia({
controller,
});
// ...
startForwarding();
This function calls the forwardWheel()
method, passing it a reference to the <video>
element the captured stream is being displayed in:
async function startForwarding() {
try {
await controller.forwardWheel(videoElem);
} catch (e) {
console.log(e);
}
}
This results in the wheel
events fired on the referenced element being forwarded to the captured display surface, allowing the capturing app to scroll it.
RetroSearch is an open source project built by @garambo | Open a GitHub Issue
Search and Browse the WWW like it's 1997 | Search results from DuckDuckGo
HTML:
3.2
| Encoding:
UTF-8
| Version:
0.7.4