GWT in Action, Second Edition

4.5. Creating a composite

Composite widgets are just what they sound like—a composite of widgets acting together as if they’re one. The internal structure of a composite is usually hidden from the outside world, and you typically can’t add or remove components unless you build it to be explicitly hidden—a composite is essentially a façade.

You may have already used a composite without knowing about it. TabPanel, which we used in the last chapter’s example, is composed of two separate widgets. There’s a TabBar that contains the tabs you click and a DeckPanel that holds the contents (see figure 4.11). When you click one of the tabs in the TabBar, you want the appropriate widget in the Deck-Panel to be displayed. TabPanel was made as a composite ...