visibilityState property
DocumentVisibilityState
get
visibilityState
The Document.visibilityState
read-only property returns the visibility of the document. It can be used
to check whether the document is in the background or in a minimized
window, or is otherwise not visible to the user.
When the value of this property changes, the
Document.visibilitychange_event
event is sent to the Document.
The Document.hidden property provides an alternative way to determine whether the page is hidden.
Implementation
external DocumentVisibilityState get visibilityState;