/** GeomG.java
 *  Plays with the geometry of line segments, using arrays & classes.
 *  It attempts to show that the median line-segments of
 *  the 3 sides of any triangle all meet at a single point.  
 *  Similar to Geom.java, but this one implements a GUI
 *  Uses classes Line and Point.
 *
 *      Dr. Henry H. Leitner
 *      Last Modified March 2, 2009
 */

import javax.swing.*;
import java.awt.event.*;
import java.awt.*;

class GeomG
{
    static JLabel prompt = new JLabel();
        
    public static void main (String[] args)
    {   
        JFrame jf = 
             new JFrame("Click mouse to input the coordinates of the vertices of a triangle");
        MyPanel m = new MyPanel();
		
        jf.getContentPane().add(m, BorderLayout.CENTER);
        jf.getContentPane().add(prompt, BorderLayout.SOUTH);
        JOptionPane.showMessageDialog(null, 
                "Click the mouse 3 times to input the vertices of a triangle!");
        jf.setSize(600, 800);
        jf.setVisible(true);
    }
    
}

class MyPanel extends JPanel implements MouseListener, MouseMotionListener
{
    static Point[] vertices = new Point [3]; 
    static Point[] midpoints = new Point [3]; 
    static Point[] intersections = new Point [3]; 
    static Line [] medians = new Line [3];
    static Point currentLocation = new Point();
    static int clicks;
	
    public void mouseExited	(MouseEvent e) {  }
    public void mouseEntered	(MouseEvent e) {  }
    public void mousePressed	(MouseEvent e) {  }
    public void mouseReleased	(MouseEvent e) {  }
    public void mouseDragged	(MouseEvent e) {  }
	
    public void mouseMoved (MouseEvent e)
     {
        GeomG.prompt.setText("("+e.getX()+", "+e.getY()+")");
        currentLocation.setX( e.getX() );
        currentLocation.setY( e.getY() );
        repaint();
     }
   
    MyPanel()
    {
        addMouseListener(this);
        addMouseMotionListener(this);
    }
   
   public void paintComponent(Graphics g)
   {  
      super.paintComponent(g);
      Graphics2D g2d = (Graphics2D)g;
      g2d.setStroke(new BasicStroke(5,1, 1));
      if (clicks == 1) 
         g.drawLine((int)vertices[0].getX(), (int)vertices[0].getY(), 
                    (int)currentLocation.getX(),(int)currentLocation.getY());
      else if (clicks == 2) 
      {
         g2d.drawLine((int)vertices[0].getX(), (int)vertices[0].getY(), 
                      (int)vertices[1].getX(), (int)vertices[1].getY());  
         g2d.drawLine((int)vertices[1].getX(), (int)vertices[1].getY(), 
                      (int)currentLocation.getX(),(int)currentLocation.getY());
      }
      else if (clicks >= 3)
      {		// draw the complete triangle
          g2d.drawLine((int)vertices[0].getX(), (int)vertices[0].getY(), 
                       (int)vertices[1].getX(), (int)vertices[1].getY());
          g2d.drawLine((int)vertices[1].getX(), (int)vertices[1].getY(), 
                       (int)vertices[2].getX(), (int)vertices[2].getY());
          g2d.drawLine((int)vertices[2].getX(), (int)vertices[2].getY(), 
                       (int)vertices[0].getX(), (int)vertices[0].getY()); 
          g2d.setColor(Color.RED.darker());
          	// now draw the medians
          for (int i =0; i <=2 ; i++)
            g2d.drawLine( (int)midpoints[i].getX(), (int)midpoints[i].getY(), 
                          (int)vertices[i].getX(), (int)vertices[i].getY());
          clicks++;
          
      }         
   }
   
   public void mouseClicked(MouseEvent e)
   {
     if (clicks < 3) 
     {
        vertices[clicks]=new Point(e.getX(), e.getY());
        clicks++; repaint();
     }
     
     if (clicks == 3 )
     {   
        System.out.print ("\nVERTICES\n");
        for (int i = 0; i < 3; i++)     
            System.out.println ("  " + vertices[i]);

        midpoints[2] = vertices[0].midpoint( vertices[1] );
        midpoints[1] = vertices[2].midpoint( vertices[0] );
        midpoints[0] = vertices[1].midpoint( vertices[2] );
        System.out.print ("MIDPOINTS:\n");
        for (int i = 0; i < 3; i++)     
            System.out.println ("  " + midpoints[i]);
        
        System.out.print ("MEDIAN LINE EQUATIONS:\n");
        for (int i = 0; i < 3; i++)
        {   
            medians[i] = new Line (midpoints[i], vertices[i]);
            System.out.println ("  " + medians[i]);
        }
        intersections[2] =  medians[0].intersect( medians[1] );    
        intersections[0] =  medians[1].intersect( medians[2] );    
        intersections[1] =  medians[2].intersect( medians[0] );  
          
        System.out.print ("Points of intersection are:\n");
        for (int i = 0; i < 3; i++)  
            System.out.print ("  " + intersections[i]);
        System.out.println();
        
       
     }		// of if
 }		// of mouseClicked	
}		// of class MyPanel