Urgent help need on swing problem

Question

Dear friends,
I met a problem and need urgent help from guru here, I am Swing newbie,
I have following code and hope to draw lines between any two components at RUN-TIME, not at design time
Please throw some skeleton code, Thanks so much!!
code:
package com.swing.test;
import java.awt.*;
import java.awt.event.*;
import java.awt.geom.*;
import javax.swing.*;
import javax.swing.event.*;
public class LongguConnectLineCommponent
    public static void main(String[] args)
        JFrame f = new JFrame("Connecting Lines");
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        f.getContentPane().add(new ConnectionPanel());
        f.setSize(400,300);
        f.setLocation(200,200);
        f.setVisible(true);
class ConnectionPanel extends JPanel
    JLabel label1, label2, label3, label4;
    JLabel[] labels;
    JLabel selectedLabel;
    int cx, cy;
    public ConnectionPanel()
        setLayout(null);
        addLabels();
        label1.setBounds( 25,  50, 125, 25);
        label2.setBounds(225,  50, 125, 25);
        label3.setBounds( 25, 175, 125, 25);
        label4.setBounds(225, 175, 125, 25);
        determineCenterOfComponents();
        ComponentMover mover = new ComponentMover();
        addMouseListener(mover);
        addMouseMotionListener(mover);
    public void paintComponent(Graphics g)
        super.paintComponent(g);
        Graphics2D g2 = (Graphics2D)g;
        g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
                            RenderingHints.VALUE_ANTIALIAS_ON);
        Point[] p;
        for(int i = 0; i < labels.length; i++)
            for(int j = i + 1; j < labels.length; j++)
                p = getEndPoints(labels, labels[j]);
//g2.draw(new Line2D.Double(p[0], p[1]));
private Point[] getEndPoints(Component c1, Component c2)
Point
p1 = new Point(),
p2 = new Point();
Rectangle
r1 = c1.getBounds(),
r2 = c2.getBounds();
int direction = r1.outcode(r2.x, r2.y);
switch(direction) // r2 located < direction > of r1
case (Rectangle.OUT_LEFT): // West
p1.x = r1.x;
p1.y = r1.y;
p2.x = r2.x + r2.width;
p2.y = r2.y;
if(r1.y > cy)
p1.y = r1.y + r1.height;
p2.y = r2.y + r2.height;
break;
case (Rectangle.OUT_TOP): // North
p1.x = r1.x;
p1.y = r1.y;
p2.x = r2.x;
p2.y = r2.y + r2.height;
if(r1.x > cx && r2.x > cx)
p1.x = r1.x + r1.width;
p2.x = r2.x + r2.width;
break;
case (Rectangle.OUT_LEFT + Rectangle.OUT_TOP): // NW
p1.x = r1.x;
p1.y = r1.y;
p2.x = r2.x + r2.width;
p2.y = r2.y;
if(r1.y > r2.y + r2.height)
p2.y = r2.y + r2.height;
break;
case (Rectangle.OUT_RIGHT): // East
p1.x = r1.x + r1.width;
p1.y = r1.y;
p2.x = r2.x;
p2.y = r2.y;
if(r1.y > cy)
p1.y = r1.y + r1.height;
p2.y = r2.y + r2.height;
break;
case (Rectangle.OUT_TOP + Rectangle.OUT_RIGHT): // NE
p1.x = r1.x + r1.width;
p1.y = r1.y;
p2.x = r2.x;
p2.y = r2.y;
if(r1.y > cy)
p1.y = r1.y + r1.height;
p2.y = r2.y + r2.height;
if(r1.y > r2.y + r2.height)
p1.y = r1.y;
else
if(r1.y > r2.y + r2.height)
p2.y = r2.y + r2.height;
break;
case (Rectangle.OUT_BOTTOM): // South
p1.x = r1.x;
p1.y = r1.y + r1.height;
p2.x = r2.x;
p2.y = r2.y;
if(r1.x > cx && r2.x > cx)
p1.x = r1.x + r1.width;
p2.x = r2.x + r2.width;
break;
case (Rectangle.OUT_RIGHT + Rectangle.OUT_BOTTOM): // SE
p1.x = r1.x + r1.width;
p1.y = r1.y + r1.height;
p2.x = r2.x;
p2.y = r2.y;
break;
case (Rectangle.OUT_BOTTOM + Rectangle.OUT_LEFT): // SW
p1.x = r1.x;
p1.y = r1.y + r1.height;
p2.x = r2.x;
p2.y = r2.y;
if(r1.x > r2.x + r2.width)
p2.x = r2.x + r2.width;
if(r1.x > cx && r2.x > cx)
p1.x = r1.x + r1.width;
p2.x = r2.x + r2.width;
return new Point[] {p1, p2};
private void determineCenterOfComponents()
int
xMin = Integer.MAX_VALUE,
yMin = Integer.MAX_VALUE,
xMax = 0,
yMax = 0;
for(int i = 0; i < labels.length; i++)
Rectangle r = labels[i].getBounds();
if(r.x < xMin)
xMin = r.x;
if(r.y < yMin)
yMin = r.y;
if(r.x + r.width > xMax)
xMax = r.x + r.width;
if(r.y + r.height > yMax)
yMax = r.y + r.height;
cx = xMin + (xMax - xMin)/2;
cy = yMin + (yMax - yMin)/2;
private class ComponentMover extends MouseInputAdapter
Point offsetP = new Point();
boolean dragging;
public void mousePressed(MouseEvent e)
Point p = e.getPoint();
for(int i = 0; i < labels.length; i++)
Rectangle r = labels[i].getBounds();
if(r.contains(p))
selectedLabel = labels[i];
offsetP.x = p.x - r.x;
offsetP.y = p.y - r.y;
dragging = true;
break;
public void mouseReleased(MouseEvent e)
dragging = false;
public void mouseDragged(MouseEvent e)
if(dragging)
Rectangle r = selectedLabel.getBounds();
r.x = e.getX() - offsetP.x;
r.y = e.getY() - offsetP.y;
selectedLabel.setBounds(r.x, r.y, r.width, r.height);
determineCenterOfComponents();
repaint();
private void addLabels()
label1 = new JLabel("Label 1");
label2 = new JLabel("Label 2");
label3 = new JLabel("Label 3");
label4 = new JLabel("Label 4");
labels = new JLabel[] {
label1, label2, label3, label4
for(int i = 0; i < labels.length; i++)
labels[i].setHorizontalAlignment(SwingConstants.CENTER);
labels[i].setBorder(BorderFactory.createEtchedBorder());
add(labels[i]);

Answer 1

If you need some help, be respectful of the forum rules and people will help. By using "urgent" in the title and bumping your message every 2 hours you're just asking to be ignored (which is what you ended up with).