keep focus on the modal

When I have two pages, one for a modal

	pages := tview.NewPages()
	pages.AddPage("background", background, true, true)
	pages.AddPage("modal", modal(edit, 50, 20), true, true)

I can still switch focus with the mouse and access the controls that are in the background. Is there an easy way to disable this?

I know I could use HidePage() before I open the modal but I would like to still have the background visible - just not accessible.