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.
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.