public JFrame() throws HeadlessException 
{
        frameInit();
}

Constructs a new frame with an empty title which is initially invisible.

Throws:

HeadlessException - - when GraphicsEnvironment.isHeadless() returns true

 public JFrame(String title) throws HeadlessException 
{
        super(title);
        frameInit();
}

Constructs a new frame with the specified title which is initially invisible.

Parameters:

title - - title of the frame; if title is null, an empty title is assumed

Throws:

HeadlessException - - when GraphicsEnvironment.isHeadless() returns true

 public JFrame(GraphicsConfiguration gc) 
{
        super(gc);
        frameInit();
}

Constructs a new frame in the specified GraphicsConfiguration and an empty title.

Parameters:

gc - - the GraphicsConfiguration to construct the frame; if gc is null, the system default GraphicsConfiguration is assumed

 public JFrame(String title,
    GraphicsConfiguration gc) 
{
        super(title, gc);
        frameInit();
}

Constructs a new frame in the specified GraphicsConfiguration and the specified title.

Parameters:

title - - title of the frame; if title is null, an empty title is assumed

gc - - the GraphicsConfiguration to construct the frame; if gc is null, the system default GraphicsConfiguration is assumed

 protected  void addImpl(Component comp,
    Object constraints,
    int index) 
{
        if (isRootPaneCheckingEnabled()) {
            getContentPane().add(comp, constraints, index);
            return;
        }
        super.addImpl(comp, constraints, index);
}

 protected JRootPane createRootPane() 
{
        return new JRootPane();
}

Called by the constructors to create the default rootPane property.

 protected  void frameInit() 
{
        setRootPaneCheckingEnabled(true);
        setRootPane(createRootPane());
        setLocale(JComponent.getDefaultLocale());
        // check isDefaultLookAndFeelDecorated()
        if (isDefaultLookAndFeelDecorated()) {
            setUndecorated(Utilities.lookAndFeelSupportsWindowDecorations());
            getRootPane().setWindowDecorationStyle(JRootPane.FRAME);
        }
        setBackground(getContentPane().getBackground());
        // enable events
        enableEvents(AWTEvent.WINDOW_EVENT_MASK);
        enableEvents(AWTEvent.KEY_EVENT_MASK);
        setFocusTraversalPolicy(KeyboardFocusManager.getCurrentKeyboardFocusManager()
                .getDefaultFocusTraversalPolicy());
}

Called by the constructors to init JFrame

 public AccessibleContext getAccessibleContext() 
{
        if (accessibleContext == null) {
            accessibleContext = new AccessibleJFrame();
        }
        return accessibleContext;
}

Returns the accessible context for the frame.

 public Container getContentPane() 
{
        return getRootPane().getContentPane();
}

Returns the contentPane property.

 public int getDefaultCloseOperation() 
{
        return defaultCloseOperation;
}

Returns defaultCloseOperation value.

 public Component getGlassPane() 
{
        return getRootPane().getGlassPane();
}

Returns glassPane property.

 public JMenuBar getJMenuBar() 
{
        return getRootPane().getJMenuBar();
}

Returns the menu bar for the frame

 public JLayeredPane getLayeredPane() 
{
        return getRootPane().getLayeredPane();
}

Returns layeredPane property.

 public JRootPane getRootPane() 
{
        return rootPane;
}

Get rootPane property.

 static Frame getSharedOwner() 
{
        if (sharedFrame == null) {
            sharedFrame = new Frame();
        }
        return sharedFrame;
}

Returns the frame that is used as a default shared owner for JDialog and JWindow.

 public static boolean isDefaultLookAndFeelDecorated() 
{
        return defaultLookAndFeelDecorated;
}

 protected boolean isRootPaneCheckingEnabled() 
{
        return rootPaneCheckingEnabled;
}

Returns rootPaneCheckingEnabled value.

 protected String paramString() 
{
        String result = super.paramString();
        if (getRootPane() != null) {
            result += ",rootPane=" + getRootPane().toString();
        } else {
            result += ",rootPane=null";
        }
        return result;
}

Returns string representation of this frame.

 protected  void processWindowEvent(WindowEvent e) 
{
        super.processWindowEvent(e);
        if (e.getID() == WindowEvent.WINDOW_CLOSING) {
            switch (getDefaultCloseOperation()) {
                case DISPOSE_ON_CLOSE: // dispose
                    dispose();
                    break;
                case HIDE_ON_CLOSE: // hide
                    setVisible(false);
                    break;
                case DO_NOTHING_ON_CLOSE: // do nothing
                    break;
                case EXIT_ON_CLOSE: // exit
                    System.exit(0);
                    break;
            }
        }
}

Implements actions depending on defaultCloseOperation property.

 public  void remove(Component comp) 
{
        // Note: differs from JInternalFrame's behavior,
        // how titlePane is removed?
        if (comp == getRootPane()) {
            // remove directly from JDialog
            super.remove(comp);
        } else {
            getContentPane().remove(comp);
        }
}

 public  void setContentPane(Container contentPane) 
{
        getRootPane().setContentPane(contentPane);
}

Sets contentPane property.

 public  void setDefaultCloseOperation(int operation) 
{
        int oldOperation = getDefaultCloseOperation();
        switch (operation) {
            case DO_NOTHING_ON_CLOSE:
            case HIDE_ON_CLOSE:
            case DISPOSE_ON_CLOSE:
                defaultCloseOperation = operation;
                break;
            case EXIT_ON_CLOSE:
                SecurityManager security = System.getSecurityManager();
                if (security != null) {
                    security.checkExit(0);
                }
                defaultCloseOperation = operation;
                break;
            default:
                throw new IllegalArgumentException(
                    Messages.getString("swing.B2","defaultCloseOperation", //$NON-NLS-1$ //$NON-NLS-2$
                        "DO_NOTHING_ON_CLOSE, HIDE_ON_CLOSE, DISPOSE_ON_CLOSE, EXIT_ON_CLOSE")); //$NON-NLS-1$ 
        }
        firePropertyChange("defaultCloseOperation", oldOperation, operation);
}

Sets defaultCloseOperation property. This is a bound property.

 public static  void setDefaultLookAndFeelDecorated(boolean defaultLookAndFeelDecorated) 
{
        JFrame.defaultLookAndFeelDecorated = defaultLookAndFeelDecorated;
}

 public  void setGlassPane(Component glassPane) 
{
        getRootPane().setGlassPane(glassPane);
}

Set glassPane property.

 public  void setIconImage(Image image) 
{
        Image oldValue = getIconImage();
        super.setIconImage(image);
        firePropertyChange(StringConstants.ICON_IMAGE_PROPERTY, oldValue, image);
}

 public  void setJMenuBar(JMenuBar menuBar) 
{
        getRootPane().setJMenuBar(menuBar);
}

Sets the menu bar for the frame.

 public  void setLayeredPane(JLayeredPane layeredPane) 
{
        getRootPane().setLayeredPane(layeredPane);
}

Sets layeredPane property.

 public  void setLayout(LayoutManager layout) 
{
        if (isRootPaneCheckingEnabled()) {
            getContentPane().setLayout(layout);
        } else {
            super.setLayout(layout);
        }
}

 protected  void setRootPane(JRootPane root) 
{
        if (rootPane != null) {
            remove(rootPane);
        }
        rootPane = root;
        if (root != null) {
            super.addImpl(root, null, 0);
        }
}

Set rootPane property.

 protected  void setRootPaneCheckingEnabled(boolean enabled) 
{
        rootPaneCheckingEnabled = enabled;
}

Sets rootPaneCheckingEnabled.

 public  void update(Graphics g) 
{
        paint(g);
}

Just calls paint(g). This method was overridden to prevent an unnecessary call to clear the background.