web api instance property
Document: fullscreenElement property
The
Document.fullscreenElement read-only
property returns the Element that is currently being presented in
fullscreen mode in this document, or null if fullscreen mode is not
currently in use.
Although this property is read-only, it will not throw if it is modified (even in strict mode); the setter is a no-operation and it will be ignored.
Value
The Element object that’s currently in fullscreen mode; if fullscreen
mode isn’t currently in use by the document, the returned
value is null. If there are multiple elements in fullscreen mode, the topmost (most recently requested) element is returned.
Examples
This example presents a function, isVideoInFullscreen(), which looks at
the value returned by fullscreenElement; if the document is in fullscreen
mode (fullscreenElement isn’t null) and the fullscreen
element’s nodeName is VIDEO, indicating a
<video> element, the function returns true, indicating
that the video is in fullscreen mode.
function isVideoInFullscreen() {
if (document.fullscreenElement?.nodeName === "VIDEO") {
return true;
}
return false;
}