8.3 Basic RootPaneContainers

For the rest of this chapter, we'll look at some basic containers (JFrame, JWindow, and JApplet) that implement RootPaneContainer and use JRootPane. First, we'll take a quick look at a simple interface called WindowConstants.

8.3.1 The WindowConstants Interface

WindowConstants is a simple interface containing only constants. It is implemented by JFrame, JDialog, and JInternalFrame.

8.3.1.1 Constants

The constants defined in WindowConstants specify possible behaviors in response to a window being closed. These values are shown in Table 8-7.

Table 8-7. JWindowConstants constants

Constant	Type	Description
DISPOSE_ON_CLOSE	int	Disposes window when closed
DO_NOTHING_ON_CLOSE	int	Does nothing when closed
EXIT_ON_CLOSE1.4, *	int	Exits the virtual machine when closed
HIDE_ON_CLOSE	int	Hides window when closed
1.4since 1.4 *This constant was added in 1.4, although a matching constant was defined in the 1.3 JFrame class.

In the next section, we'll look at a strategy for exiting the application in response to a frame being closed .