Java Reference
In-Depth Information
public JFrame()
Constructor that creates an object of the class JFrame .
public JFrame(String title)
Constructor that creates an object of the class JFrame with the title given as the argument.
public Component add(Component componentAdded)
Adds componentAdded to the JFrame. Typically used as a void method.
public Container getContentPane()
Returns the content pane of the calling JFrame object. Container is a class in the package
java.awt .
To set the color of a JFrame , use
getContentPane().setBackground(Color c)
If you use setBackground without the getContentPane() , you will not get any error
messages, but you will probably not see the color.
public void setDefaultCloseOperation( int operation)
Sets the action that will happen by default when the user clicks the close-window button.
The argument should be one of the following defi ned constants:
JFrame.DO_NOTHING_ON_CLOSE: Do nothing. The JFrame does nothing, but if there are any
registered window listeners, they are invoked. (Window listeners are explained in Chapter 18.)
JFrame.HIDE_ON_CLOSE: Hide the frame after invoking any registered WindowListener
objects.
JFrame.DISPOSE_ON_CLOSE: Hide and dispose the frame after invoking any registered win-
dow listeners. When a window is disposed , it is eliminated but the program does not end. To
end the programs, use the next constant as an argument to setDefaultCloseOperation .
JFrame.EXIT_ON_CLOSE: Exit the application using the System exit method. (Do not
use this for frames in applets. Applets are discussed on the accompanying CD.)
If no action is specifi ed using the method setDefaultCloseOperation , then the default
action taken is JFrame.HIDE_ON_CLOSE.
Throws:
IllegalArgumentException if the argument is not one of the values listed previously.
SecurityException if the argument is JFrame.EXIT_ON_CLOSE and the Security Manager
will not allow the caller to invoke System.exit . (You are not likely to encounter this case.)
public void setLayout(LayoutManager manager)
Makes manager the layout manager for the JFrame .
public void setSize( int width, int height)
Sets the size of the calling frame so that it has the width and height specifi ed. Pixels are the
units of length used.
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