import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Component;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Rectangle;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.lang.reflect.Field;
import java.util.LinkedList;

import javax.swing.BoxLayout;
import javax.swing.ButtonGroup;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JRadioButton;
import javax.swing.border.LineBorder;

public class PaintOrderDemo extends JFrame implements ActionListener
{
  private int onTopIndex = 2;

  public static void main(String[] args) throws Exception
  {
    EventQueue.invokeLater(new Runnable()
    {
      public void run()
      {
        new PaintOrderDemo();
      }
    });
  }

  public PaintOrderDemo()
  {
    JPanel p = new ColorBoxContainer();
    p.setLayout(new BoxLayout(p, BoxLayout.LINE_AXIS));
    add(p);
    
    p.add(new ColorBox(Color.RED));
    p.add(new ColorBox(Color.GREEN));
    p.add(new ColorBox(Color.BLUE));

    JPanel optionsPanel = new JPanel();
    JRadioButton rb1 = new JRadioButton("red", false);
    rb1.setActionCommand("0");
    rb1.addActionListener(this);
    JRadioButton rb2 = new JRadioButton("green", false);
    rb2.setActionCommand("1");
    rb2.addActionListener(this);
    JRadioButton rb3 = new JRadioButton("blue", true);
    rb3.setActionCommand("2");
    rb3.addActionListener(this);
    ButtonGroup group = new ButtonGroup();
    group.add(rb1);
    group.add(rb2);
    group.add(rb3);
    optionsPanel.add(rb1);
    optionsPanel.add(rb2);
    optionsPanel.add(rb3);    
    add(optionsPanel, BorderLayout.SOUTH);
    
    setTitle(getClass().getSimpleName());
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    pack();
    setLocationRelativeTo(null);
    setVisible(true);
  }

  class ColorBox extends JPanel
  {
    private Color color;
    
    public ColorBox(Color color)
    {
      this.color = color;
      setOpaque(false);
      setPreferredSize(new Dimension(160, 160));
      setBorder(new LineBorder(color, 4));
    }
    
    @Override
    protected void paintComponent(Graphics g)
    {
      g.setColor(new Color(0x80FFFFFF & color.getRGB(), true));
      g.fillRect(0, 0, getWidth(), getHeight());
    }

    @Override
    public void setBounds(int x, int y, int width, int height)
    {
      int index = 0;
      for (Component c : getParent().getComponents())
      {
        if (c == this)
          break;
        index++;
      }
      //overlap 25 pixels
      x += index * -25;
      super.setBounds(x, y, width, height);
    }
  }

  class ColorBoxContainer extends JPanel
  {
    @Override
    public boolean isOptimizedDrawingEnabled()
    {
      return false;
    }
    
    private LinkedList<Component> arrangeChildComponents()
    {
      LinkedList<Component> components = new LinkedList<Component>();
      for (int k = 0; k < getComponentCount(); k++)
      {
        if (k == onTopIndex)
          components.addFirst(getComponent(k));
        else
          components.add(getComponent(k));
      }
      return components;
    }
    
    @Override
    protected void paintChildren(Graphics g)
    {
      final int ANCESTOR_USING_BUFFER = 1;
      final int IS_PAINTING_TILE = 2;

      synchronized (getTreeLock())
      {
        int i = getComponentCount() - 1;
        if (i < 0)
          return;

        Rectangle clipBounds = g.getClipBounds();
        if (clipBounds == null)
          clipBounds = new Rectangle(0, 0, getWidth(), getHeight());

        //create list - the first item in the list will be painted on top 
        LinkedList<Component> components = arrangeChildComponents();

        for (; i >= 0; i--)
        {
          Component comp = components.get(i);

          if (!(comp instanceof JComponent) || !comp.isVisible())
            continue;

          JComponent c = (JComponent) comp;
          Rectangle cr = c.getBounds(new Rectangle());
          if (!clipBounds.intersects(cr))
            continue;

          Graphics cg = g.create(cr.x, cr.y, cr.width, cr.height);
          cg.setColor(c.getForeground());
          cg.setFont(c.getFont());
          boolean resetFlag = false;

          if (getFlag(ANCESTOR_USING_BUFFER))
          {
            setFlag(c, ANCESTOR_USING_BUFFER, true);
            resetFlag = true;
          }

          if (getFlag(IS_PAINTING_TILE))
          {
            setFlag(c, IS_PAINTING_TILE, true);            
            resetFlag = true;
          }

          c.paint(cg);
          cg.dispose();
          
          if (resetFlag)
          {
            setFlag(c, ANCESTOR_USING_BUFFER, false);
            setFlag(c, IS_PAINTING_TILE, false);
          }
        }
      }
    }

    private boolean getFlag(int aFlag)
    {
      int flags = 0;
      try
      {
        Field field = JComponent.class.getDeclaredField("flags");
        field.setAccessible(true);
        flags = (Integer) field.get(this);
      }
      catch (Exception e)
      {
        throw new RuntimeException(e);
      }

      int mask = (1 << aFlag);
      return ((flags & mask) == mask);
    }

    private void setFlag(JComponent c, int aFlag, boolean aValue)
    {
      int flags = 0;
      try
      {
        Field field = JComponent.class.getDeclaredField("flags");
        field.setAccessible(true);
        flags = (Integer) field.get(c);
      }
      catch (Exception e)
      {
        throw new RuntimeException(e);
      }

      if (aValue)
        flags |= (1 << aFlag);
      else
        flags &= ~(1 << aFlag);

      try
      {
        Field field = JComponent.class.getDeclaredField("flags");
        field.setAccessible(true);
        field.set(c, flags);
      }
      catch (Exception e)
      {
        throw new RuntimeException(e);
      }
    }
  }

  public void actionPerformed(ActionEvent evt)
  {
    onTopIndex = Integer.parseInt(evt.getActionCommand());
    repaint();
  }

}