A SpinBox allows you to display, in sequence, a ring of choices. The SpinBox consists of a non-editable text area where a single choice is displayed; there are two arrow buttons next to the the text area, one on each side, for cycling through the choices. (See Figure 3-29.)
Figure 31. A SpinBox.
To use a SpinBox to change the displayed choice:
One arrow acts as the increment arrow, and the other as the decrement arrow. The increment arrow lets you progress through the list of choices or increase the numeric value. For example, if the SpinBox displays a date, the increment arrow changes "March" to "April." If the SpinBox displays a numeric value (for example, a quantity), the increment arrow increases the value. Similarly, the decrement arrow lets you back up through the list (from "March" to "February"), or decrease the numeric value.
If you have clicked on SpinBox arrows or text, or if you have tabbed to the SpinBox via the keyboard, the SpinBox has input focus. You can then press the arrow keys on the keyboard to spin the choices, instead of pressing Button 1 on a displayed arrow.