The populate_popup signal gets emitted before showing the context menu of the entry.
If you need to add items to the context menu, connect to this signal and append your items to the
widget, which will be a
Menu in this case.
If populate_all is true, this signal
will also be emitted to populate touch popups. In this case,
widget will be a different container, e.g. a
Toolbar. The signal handler should not make assumptions about the type of
the container that is being populated