Gtk.AppChooserWidget::populate-popup

function callback(app_chooser_widget, menu:Gtk.Menu, application:Gio.AppInfo, ):void;

Emitted when a context menu is about to popup over an application item. Clients can insert menu items into the provided Gtk.Menu object in the callback of this signal; the context menu will be shown over the item if at least one item has been added to the menu.