Function rerun::external::eframe::egui::menu::menu_custom_button

pub fn menu_custom_button<R>(
    ui: &mut Ui,
    button: Button<'_>,
    add_contents: impl FnOnce(&mut Ui) -> R
) -> InnerResponse<Option<R>>

Construct a top level menu with a custom button in a menu bar.

Responds to primary clicks.

Returns None if the menu is not open.