Programmation Java/swing/Distance

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.border.*;
 
public class Distance extends JFrame implements ActionListener
{
 
	private JLabel textXA,textYA,textXB,textYB,textDistance;
	private JTextField editXA,editXB,editYA,editYB,editDistance;
	private JButton editA,editB;
	private Point A,B;
 
	public static void main(String [] args)
	{
	Distance app=new Distance();
	}
 
	Distance()
	{
		setBounds(10,10,400,300);
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
 
		Container c;
		c=getContentPane();
 
		BorderLayout bl=new BorderLayout();
		c.setLayout(bl);
 
 
		JPanel p=new JPanel();
		p.setLayout(null);
 
		textXA= new JLabel("Abscisse de A : ");
		textXA.setBounds(10,20,100,20);
		p.add(textXA);
 
		textYA= new JLabel("ordonnée de A : ");
		textYA.setBounds(10,50,100,20);
		p.add(textYA);
 
		textXB= new JLabel("Abscisse de B : ");
		textXB.setBounds(10,90,100,20);
		p.add(textXB);
 
		textYB= new JLabel("Ordonnée de B : ");
		textYB.setBounds(10,120,100,20);
		p.add(textYB);
 
		textDistance= new JLabel("La distance AB vaut : ");
		textDistance.setBounds(10,170,150,20);
		p.add(textDistance);
 
		editXA=new JTextField(20);
		editXA.setBounds(120,20,100,20);
		editXA.setEditable(false);
		p.add(editXA);
 
		editYA=new JTextField(20);
		editYA.setBounds(120,50,100,20);
		editYA.setEditable(false);
		p.add(editYA);
 
 
		editXB=new JTextField(20);
		editXB.setBounds(120,90,100,20);
		editXB.setEditable(false);
		p.add(editXB);
 
		editYB=new JTextField(10);
		editYB.setBounds(120,120,100,20);
		editYB.setEditable(false);
		p.add(editYB);
 
		editDistance=new JTextField(20);
		editDistance.setBounds(150,170,150,20);
		editDistance.setEditable(false);
		p.add(editDistance);
 
		Border bord=BorderFactory.createRaisedBevelBorder();
		editA=new JButton("MODIFIER A");
		editA.setActionCommand("EDITA");
		editA.addActionListener(this);
		editA.setBorder(bord);
		editA.setBounds(240,35,100,20);
		p.add(editA);
 
		editB=new JButton("MODIFIER B");
		editB.setActionCommand("EDITB");
		editB.addActionListener(this);
		editB.setBorder(bord);
		editB.setBounds(240,105,100,20);
		p.add(editB);
 
 
 
		c.add(p, BorderLayout.CENTER);
		setVisible(true);
 
		A=new Point();
		B=new Point();
		ShowPoint();
	}
 
 
	void ShowPoint()
	{
	editXA.setText(String.valueOf(A.getX()));	
	editYA.setText(String.valueOf(A.getY()));	
	editXB.setText(String.valueOf(B.getX()));	
	editYB.setText(String.valueOf(B.getY()));	
	editDistance.setText(String.valueOf(A.distance(B)));
	}
 
	public void actionPerformed(ActionEvent e)
	{
 
		if(e.getActionCommand().equals("EDITA"))
		{
        PointDialog dialog=new PointDialog(this,"Modification du point A",A);
	 dialog.setVisible(true);
	 ShowPoint();
		}
		else
		if(e.getActionCommand().equals("EDITB"))
		{
		PointDialog dialog=new PointDialog(this,"Modification du point B",B);
		dialog.setVisible(true);
		ShowPoint();
		}
	}
}

public class Point {
 
	private double x,y;
 
	Point()
	{
	x=0;
	y=0;
	}
 
	public double getX(){return x;}
	double getY(){return y;}
 
	void setXY(double x,double y)
	{
	this.x=x;
	this.y=y;
	}
 
	double distance(Point P)
	{
	double dx,dy;
	dx=x-P.x;
	dy=y-P.y;
	return java.lang.Math.sqrt(dx*dx+dy*dy);
	}
}

import javax.swing.*;
import javax.swing.border.Border;
import java.awt.event.*;
import java.awt.*;
 
public class PointDialog extends JDialog implements ActionListener
{
	private Point P;
	JButton OK,Cancel;
	JLabel textX,textY;
	JTextField editX,editY;
 
	PointDialog(JFrame f,String s,Point P)
	{
    super(f,s,true);
    this.P=P;
    setLocationRelativeTo(f);
    setBounds(500,100,400,200);
    setDefaultCloseOperation(JDialog.DO_NOTHING_ON_CLOSE);
 
    Container c=getContentPane();
    c.setLayout(null);
 
    textX=new JLabel("Abscisse du point :");
    textX.setBounds(10,20,120,20);
    c.add(textX);
 
    textY=new JLabel("Ordonnée du point :");
    textY.setBounds(10,50,120,20);
    c.add(textY);
 
    editX=new JTextField(20);
	editX.setBounds(140,20,100,20);
	c.add(editX);
 
	editY=new JTextField(20);
	editY.setBounds(140,50,100,20);
	c.add(editY);
 
	Border bord=BorderFactory.createRaisedBevelBorder();
	OK=new JButton("OK");
	OK.setActionCommand("OK");
	OK.addActionListener(this);
	OK.setBorder(bord);
	OK.setBounds(260,25,60,20);
	c.add(OK);
 
	Cancel=new JButton("Annuler");
	Cancel.setActionCommand("CANCEL");
	Cancel.addActionListener(this);
	Cancel.setBorder(bord);
	Cancel.setBounds(260,50,60,20);
	c.add(Cancel);
 
	ShowPoint();
	}
 
	private void ShowPoint()
	{
		editX.setText(String.valueOf(P.getX()));	
		editY.setText(String.valueOf(P.getY()));	
	}
 
 
	public void actionPerformed(ActionEvent e)
	{
	double x,y;
	if(e.getActionCommand().equals("OK"))
			{
		boolean ok=true;
 
		if(ok)	{
			 try{
				 x=(new Double(editX.getText())).doubleValue();
				}catch(RuntimeException ex)
				{x=P.getX();editX.setText(String.valueOf(x));ok=false;}
 
				try{
					 y=(new Double(editY.getText())).doubleValue();
					}catch(RuntimeException ex)
					{y=P.getY();editY.setText(String.valueOf(y));ok=false;}
				if(ok)
					{
					P.setXY(x,y);
					dispose();
					}
				}
		}
		else if(e.getActionCommand().equals("CANCEL"))
			{
			dispose();
			}
	}
 
}