JSplitPane Problem Example

import java.awt.Color;
import java.awt.GridLayout;
import java.awt.Menu;
import java.awt.MenuBar;
import java.awt.MenuItem;
import java.awt.Panel;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.JFrame;
import javax.swing.JSplitPane;


@SuppressWarnings("serial")
public class Frame extends JFrame implements ActionListener{

    private JSplitPane splitPaneRight, splitPaneLeft;

    public Frame()
    {
        setSize(1280, 720);
        setLayout(new GridLayout(1, 1));

        MenuBar mb = new MenuBar();
        Menu m = new Menu("ResetLayout");
        MenuItem mi = new MenuItem("ResetLayout");
        m.add(mi);
        mb.add(m);

        setMenuBar(mb);

        mi.addActionListener(this);

        Panel p = new Panel(); p.setBackground(Color.gray);

        splitPaneRight = new JSplitPane(JSplitPane.HORIZONTAL_SPLIT, p /*Center panel*/, new Panel() /*Right panel*/);
        splitPaneLeft = new JSplitPane(JSplitPane.HORIZONTAL_SPLIT, new Panel() /*Left panel*/, splitPaneRight);

        splitPaneRight.setResizeWeight(1);

        splitPaneLeft.setDividerLocation(165);
        splitPaneRight.setDividerLocation(830);

        add(splitPaneLeft);

        setVisible(true);
    }

    public void actionPerformed(ActionEvent ev)
    {
        setSize(1280, 720);
        splitPaneLeft.setDividerLocation(165);
        splitPaneRight.setDividerLocation(830);
    }

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