25. What is the advantage of the event-delegation model over the earlier event-inheritance model?

Answer
The event-delegation model has two advantages over the event-inheritance model. First, it enables event handling to be handled by objects other than the ones that generate the events (or their containers). This allows a clean separation between a component's design and its use. The other advantage of the event-delegation model is that it performs much better in applications where many events are generated. This performance improvement is due to the fact that the event-delegation model does not have to repeatedly process unhandled events, as is the case of the event-inheritance model.

26. How can a GUI component handle its own events?

Answer
A component can handle its own events by implementing the required event-listener interface and adding itself as its own event listener.

27. How are the elements of a GridBagLayout organized?

Answer

The elements of a GridBagLayout are organized according to a grid. However, the elements are of different sizes and may occupy more than one row or column of the grid. In addition, the rows and columns may have different sizes

28. What advantage do Java's layout managers provide over traditional windowing systems?

Answer
Java uses layout managers to lay out components in a consistent manner across all windowing platforms. Since Java's layout managers aren't tied to absolute sizing and positioning, they are able to accomodate platform-specific differences among windowing systems.

29. What is the difference between a Choice and a List?

Answer
A Choice is displayed in a compact form that requires you to pull it down to see the list of available choices. Only one item may be selected from a Choice. A List may be displayed in such a way that several List items are visible. A List supports the selection of one or more List items

30. What Checkbox method allows you to tell if a Checkbox is checked?

Answer
getState()

31. What is the purpose of the enableEvents() method?

Answer
The enableEvents() method is used to enable an event for a particular object. Normally, an event is enabled when a listener is added to an object for a particular event. The enableEvents() method is used by objects that handle events by overriding their event-dispatch methods.