CheckBox, shown in Figure 9.3, is a familiar control. But wait a minute...aren’t we in the middle of talking about buttons? Yes, but consider the characteristics of a
It has a single piece of externally supplied content (so the standard check box doesn’t count).
It has a notion of being clicked by pointer or keyboard.
It retains a state of being checked or unchecked when clicked.
It supports a three-state mode, where the state ...