Swing Overlapping components

Question

I have two AWT components in a Frame, Panel A and Panel B. I would like panel A to be sized to the height width of the frame (and maintain that size on frame resize), but I

Answer 1

Maybe I'm missing something. If B is fixed size and is at (0,0) and A runs the full width what's the use of having B overlap A? You will never see anything that is placed under B.

I can't think of any of the default layout managers, but Orielly has this one you can use: relative layout manager (see source code link) with documentation. I haven't used it in a long while, but it should beat managing the layout yourself.

Answer 2

Take a look at JLayeredPanes. Here is a tutorial.

edit:

If panelA is an AWT component, you will be hard pressed to get panelB to overlap. From Sun's article entitled Mixing Heavy and Light Components:

Do not mix lightweight (Swing) and heavyweight (AWT) components within a container where the lightweight component is expected to overlap the heavyweight one.

However, if you are looking to have panelA fill the Frame completely, why not add panelB as a component of panelA?

Edit2:

If you can make panelB a heavyweight component, then you can use the JLayeredPane.

Here is a quick mockup that shows how:

public static void main(String[] args){
    new GUITest();
}

public GUITest() {
    frame = new JFrame("test");
    frame.setSize(300,300);
    addStuffToFrame();
    SwingUtilities.invokeLater(new Runnable(){
        public void run() {
            frame.setVisible(true);
        }
    });

}       

private void addStuffToFrame() {    
    Panel awtPanel = new Panel();
    awtPanel.setBackground(Color.blue);
    //here you can fool around with the pane:
    //first, you can see how the layered pane works by switching the 
    //DEFUALT_LAYER and PALLETTE_LAYER back and forth between the two panels
    //and re-compiling to see the results
    awtPanel.setSize(200,300);
    frame.getLayeredPane().add(awtPanel, JLayeredPane.DEFAULT_LAYER);
    //next you comment out the above two lines and 
    //uncomment the following line. this will give you the desired effect of
    //awtPanel filling in the entire frame, even on a resize. 
    //frame.add(awtPanel);

    Panel awtPanel2 = new Panel();
    awtPanel2.setBackground(Color.red);
    awtPanel2.setSize(300,200);
    frame.getLayeredPane().add(awtPanel2,JLayeredPane.PALETTE_LAYER);
}   

Answer 3

Your best bet is to have your own LayoutManager. The easiest way is probably to extend or proxy BorderLayout, and have a specific case to layout panel B.