A GtkSpinButton is a widget offering a displayed
numerical value which can be incremented or decremented within a pre-set
range by the user's clicking on one of two arrow buttons, or by using the
Up and Down arrow keys.
The display area is a GtkEntry; the spinbutton
object currently provides the only built-in means of masking input in
GTK+. If you want to restrict the user to the values displayed rather
than allowing keyboard input, call
set_editable() from the spinbutton.
See also: GtkAdjustment,