void Gtk_ScrollingLabel::setStartSignal (
setStartSignal() will make the event box listen for the
$signal and will envoke
startScroll() when ever it is heard. The signal should
be a signal that GtkEventBox listens for normally
or a button press event.
The Gtk signal to connect to startScroll().
returns The handler id for the connection.
This function can not be called statically.