How to differentiate between mouse and keyboard

[Igor Korot <ikorot01 gmail com>]

Hi, ALL,
>From the GTK+ docs:
http://developer.gnome.org/gtk3/stable/GtkComboBox.html#GtkComboBox-popup

"The ::popup signal is a keybinding signal which gets emitted to popup
the combo box list.

The default binding for this signal is Alt+Down."

Is it possible to know if the user pressed the keys combination or
clicked the mouse
on the button arrow?

Thank you.