egui menus (Ui::menu_button) and context menus (Response::context_menu) are implemented using the egui::menu module.

There are also tooltips (Response::on_hover_ui etc) and ComboBox popups, both implemented using egui::containers::popup.

It would be nice to unify these systems.

Things I would like to accomplish:

• Being able to open a popup on:
  • hover (tooltip)
  • click (menu)
  • right-click or long-press (context menu)
• Nest sub-menus everywhere (currently not possible in tooltips)
• Call ui.close_menu to close a tooltip and popup (currently only works for menus)

At the same time it would be great to take a naming pass on all these things, and look up what they are commonly called in other ui libraries.