Q:

Java Swing Responsive Absolute Positioning

I am newby to java swing gui and I cannot figure out this problem 
Lets assume I Have a Jframe size 100,100 I have 4 button positions 
        left top widht height
button1 0    0   10    10 // left up
button2 90   0   10    10 // right up
button3 45   45  10    10 // middle
button4 0    90  10    10 // left down
button5 90   90  10    10 // right down

All of left top width height sized scaled from 100,100.
I need using Absolute positioning (Becaouse my real situation different left,top,width,height) But responsiveness I consider maybe I can use factors to multiple the left,right,width,height values 
For example after running gui if I change frame to 400,200 then new positions should be 
button1 0    0   40   20 // left up
button2 360  0   40   20 // right up
button3 180  90  40   20 // middle
button4 0    180 40   20 // left down
button5 360  180 40   20 // right down

x factor = 400/100=4 and y factor = 200/100=2
How can I listen Jframe's changes from 100,100 to 400,200 and develop above approach. Any information appreciated.
EDIT
I get left top width height from different service and my example could be like 
        left top widht height
button1 01   04  11    14  
button2 91   0   10    10    
button3 44   45  9     14  
button4 0    90  10    10 
button5 90   90  1     1 

A:

I need using Absolute positioning

When ever you think you need "absolute positioning", you don't.  Seriously, I've never had a need to use one which wasn't solved through some other means, either an existing layout or a custom layout.
The layout management API is designed to do exactly what you're asking, better to make use of it and save your hair.
This is a pretty simple example using GridBagLayout and yes, if the buttons had different heights, it would still cope

import java.awt.EventQueue;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;

public class Test {

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

    public Test() {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                try {
                    UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
                } catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
                    ex.printStackTrace();
                }

                JFrame frame = new JFrame("Testing");
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                frame.add(new TestPane());
                frame.pack();
                frame.setLocationRelativeTo(null);
                frame.setVisible(true);
            }
        });
    }

    public class TestPane extends JPanel {

        public TestPane() {
            setLayout(new GridBagLayout());

            GridBagConstraints gbc = new GridBagConstraints();
            // Common properties...
            gbc.weightx = 0.5;
            gbc.weighty = 0.333;
            // Top/left
            gbc.gridx = 0;
            gbc.gridy = 0;
            gbc.anchor = GridBagConstraints.NORTHWEST;
            add(new JButton("Top left is all mine"), gbc);
            // Top/right
            gbc.gridx = 2;
            gbc.gridy = 0;
            gbc.anchor = GridBagConstraints.NORTHEAST;
            add(new JButton("Top right mine, keep out"), gbc);

            // middle
            gbc.gridx = 1;
            gbc.gridy = 1;
            gbc.anchor = GridBagConstraints.CENTER;
            add(new JButton("My precious"), gbc);

            // bottom/left
            gbc.gridx = 0;
            gbc.gridy = 2;
            gbc.anchor = GridBagConstraints.SOUTHWEST;
            add(new JButton("Got this space covered"), gbc);
            // bottom/right
            gbc.gridx = 2;
            gbc.gridy = 2;
            gbc.anchor = GridBagConstraints.SOUTHEAST;
            add(new JButton("Why is every one so unfriendly?"), gbc);
        }

    }

}

Got high buttons...

Got that covered, automatically

