Java Swing, 2nd Edition

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.

The WindowConstants Interface

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

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 .