catching the shift button (GdkButtonEvent) on a gnome app toolbar

[Wayne Schuller <k_wayne linuxpower org>]

hi everyone,

I have a gnome app toolbar with a button with callback function button_cb.

Is there a way I can tell from within button_cb whether the SHIFT button was
pressed when the toolbar button was clicked?

In my own gtk buttons I do this by catching the button_press_event signal, as
the callback looks something like this:
button_press_event_cb (GtkWidget *widget, GdkEventButton *event, gpointer data)

But the gnome app toolbar appears to use the 'clicked' signal, whose callbacks
look like this:
clicked_cb (GtkWidget *widget, gpointer data)

Is there a way I can get the event from within the button_cb function? 

Or can I make the gnome app use the button_press_event instead of the 'clicked'
event?

If possible, I'd like to make this work easily using the gnome_app toolbar.

thanks,
Wayne