Get instantly the coordinate of end and start point of line, when moving it

Question

hello guys,
i'm just wondering on how to get the coordinate of Start and End point of a line when I'm using PathWrangler wrangler = new PathWrangler(this); this latter allows the paint components to be dragged, so i want to get instantly the coordinate of the Start and End point of the line.
MY AIM IS: i want whenver an intersection between 2 lines occur( the line is being dragged so intersection may occur between the two lines) i want to draw a circle having as center the intersection of the 2 lines.
i managed to write a code that draws 2 lines and a circle having a center the intersection of both lines. here is the code:
import java.awt.*; 
    import java.awt.event.*; 
    import java.awt.geom.*; 
    import java.util.*; 
    import java.util.List; 
    import javax.swing.*; 
    import javax.swing.event.MouseInputAdapter; 
    public class SDRx extends JPanel { 
       List<Path2D.Double> paths = new ArrayList<Path2D.Double>(); 
       PathWrangler wrangler = new PathWrangler(this);
       Point p1= new Point(120,150);
       Point p2= new Point(140,210);
       Point p3= new Point(120,150);
       Point p4= new Point(110,230);               
        Line2D.Double l1=new Line2D.Double(p1,p2);
       Line2D.Double l2=new Line2D.Double(p3,p4);
        Point2D.Double inter= intersection(l1.getX1(),l1.getY1(),l1.getX2(),l1.getY2(),l2.getX1(),l2.getY1(),l2.getX2(),l2.getY2());
       Ellipse2D.Double ell= new Ellipse2D.Double(inter.getX()-25,inter.getY()-25,50,50);
       public SDRx() { 
           paths.add(wrap(l1));
           paths.add(wrap(l2));
           paths.add(wrap(ell));             
       private Path2D.Double wrap(Shape s) { 
           return new Path2D.Double(s); 
       protected void paintComponent(Graphics g) { 
           super.paintComponent(g); 
           Graphics2D g2 = (Graphics2D)g; 
           g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, 
                               RenderingHints.VALUE_ANTIALIAS_ON); 
           g2.setPaint(Color.blue); 
           for(int j = 0; j < paths.size(); j++) { 
               g2.draw(paths.get(j)); 
       public void transformPath(Path2D.Double path, AffineTransform at) { 
           path.transform(at); 
           repaint(); 
        public Point2D.Double intersection(double x1,double y1,double x2,double y2, double x3, double y3, double x4,double y4) {
      double d = (x1-x2)*(y3-y4) - (y1-y2)*(x3-x4);
      if (d == 0) return null;
      double xi = ((x3-x4)*(x1*y2-y1*x2)-(x1-x2)*(x3*y4-y3*x4))/d;
      double yi = ((y3-y4)*(x1*y2-y1*x2)-(y1-y2)*(x3*y4-y3*x4))/d;
    return new Point2D.Double(xi,yi);
       public static void main(String[] args) { 
           JFrame f = new JFrame(); 
           f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
           f.add(new SDRx()); 
           f.setSize(400,400); 
           f.setLocation(100,100); 
           f.setVisible(true); 
   }any help is appreciated.
10x

Answer 1

OK guys i'm sorry for before i said few wrong things about PathWrangler wrangler = new PathWrangler(this); i thought it was in the java library.
anyway here is the full code( i got it few weeks ago(with few modidfication) from somwhere, u can google it)
    import java.awt.*; 
    import java.awt.event.*; 
    import java.awt.geom.*; 
    import java.util.*; 
    import java.util.List; 
    import javax.swing.*; 
    import javax.swing.event.MouseInputAdapter; 
    public class SDRx extends JPanel { 
       List<Path2D.Double> paths = new ArrayList<Path2D.Double>(); 
       PathWrangler wrangler = new PathWrangler(this);
       Point p1= new Point(120,150);
       Point p2= new Point(140,210);
       Point p3= new Point(120,150);
       Point p4= new Point(110,230);               
        Line2D.Double l1=new Line2D.Double(p1,p2);
       Line2D.Double l2=new Line2D.Double(p3,p4);
        Point2D.Double inter= intersection(l1.getX1(),l1.getY1(),l1.getX2(),l1.getY2(),l2.getX1(),l2.getY1(),l2.getX2(),l2.getY2());
       Ellipse2D.Double ell= new Ellipse2D.Double(inter.getX()-25,inter.getY()-25,50,50);
       public SDRx() { 
           paths.add(wrap(l1));
           paths.add(wrap(l2));
           paths.add(wrap(ell));             
       private Path2D.Double wrap(Shape s) { 
           return new Path2D.Double(s); 
       protected void paintComponent(Graphics g) { 
           super.paintComponent(g); 
           Graphics2D g2 = (Graphics2D)g; 
           g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, 
                               RenderingHints.VALUE_ANTIALIAS_ON); 
           g2.setPaint(Color.blue); 
           for(int j = 0; j < paths.size(); j++) { 
               g2.draw(paths.get(j)); 
       public void transformPath(Path2D.Double path, AffineTransform at) { 
           path.transform(at); 
           repaint(); 
        public Point2D.Double intersection(double x1,double y1,double x2,double y2, double x3, double y3, double x4,double y4) {
      double d = (x1-x2)*(y3-y4) - (y1-y2)*(x3-x4);
      if (d == 0) return null;
      double xi = ((x3-x4)*(x1*y2-y1*x2)-(x1-x2)*(x3*y4-y3*x4))/d;
      double yi = ((y3-y4)*(x1*y2-y1*x2)-(y1-y2)*(x3*y4-y3*x4))/d;
    return new Point2D.Double(xi,yi);
       public static void main(String[] args) { 
           JFrame f = new JFrame(); 
           f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
           f.add(new SDRx()); 
           f.setSize(400,400); 
           f.setLocation(100,100); 
           f.setVisible(true); 
   class PathWrangler extends MouseInputAdapter { 
       SDRx component; 
       AffineTransform at = new AffineTransform(); 
       final int S = 6; 
       Rectangle net = new Rectangle(S, S); 
       Path2D.Double selectedPath; 
       Point offset = new Point(); 
       boolean dragging = false; 
       public PathWrangler(SDRx sdr) { 
           component = sdr; 
           component.addMouseListener(this); 
           component.addMouseMotionListener(this); 
       public void mousePressed(MouseEvent e) { 
           Point p = e.getPoint(); 
           net.setLocation(p.x-S/2, p.y-S/2); 
           List<Path2D.Double> list = component.paths; 
           for(int j = 0; j < list.size(); j++) { 
               Path2D.Double path = list.get(j); 
               // Use the contains method to detect RectangluarShapes 
               // and the intersects method with net to detect lines. 
              if(path.contains(p) || path.intersects(net)) { 
                   selectedPath = path; 
                   Rectangle r = selectedPath.getBounds(); 
                   offset.x = p.x - r.x; 
                   offset.y = p.y - r.y; 
                   dragging = true; 
                   break; 
       public void mouseReleased(MouseEvent e) { 
           dragging = false; 
       public void mouseDragged(MouseEvent e) { 
           if(dragging) { 
               int x = e.getX() - offset.x; 
               int y = e.getY() - offset.y; 
               Rectangle r = selectedPath.getBounds(); 
               at.setToTranslation(x-r.x, y-r.y); 
               component.transformPath(selectedPath, at);
   }  10x