Overlays / Popups

ratatui itself has no builtin facilities for widgets that render as overlay over other widgets.

For widgets that are only rendered as overlay, the solution is straight forward: render them after all widgets that should be below have been rendered.

That leaves widget that are only partial overlays, such as Menubar and Split. They solve this, by not implementing any widget trait, instead they act as widget-builders, and have a method into_widgets() that return two widgets. One for the base-rendering and one for the popup. Only those are ratatui-widgets, and they have no further configuration methods.

Event Handling

Event-handling can be structured similarly.