onShowRequested property

Called when a request is made to show the overlay.

This callback is triggered when AnchorController.show is called.

After a show request is intercepted, the showOverlay callback should be called when the overlay is ready to be shown. This can occur immediately (the default behavior), or after a delay or animation setup. Calling showOverlay makes the overlay visible in the widget tree.

If showOverlay is not called, the overlay will stay hidden.

Defaults to a callback that immediately shows the overlay.