/* 
 *  ===================================================================
 *  DemoGUI.java : Simple GUI with canvas connected to a mouse listener
 *  and buttons connected to button listeners.
 * 
 *  Written By : Mark Austin                                  May, 2005
 *  ===================================================================
 */ 

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

public class DemoGUI extends JApplet {
    Container container = null;
    DemoGraphicsScreen gs;

    public void init() {

      // 1. Get a handle on the applet's content pane.
   
      container = this.getContentPane();

      // 2. Create a graphics screen and mouse listener,
      //    and add content pane to center of applet.

      DemoGraphicsScreen gs = new DemoGraphicsScreen();
      gs.addMouseListener( new GraphicsListener( gs ));

      // 3. Create buttons and button listeners.

      JButton buttons[] = new JButton [2]; 

      buttons[0] = new JButton ("Clear");
      buttons[0].addActionListener( new ButtonAction( buttons[0], gs ));
      buttons[1] = new JButton ("Triangle");
      buttons[1].addActionListener( new ButtonAction( buttons[1], gs ));

      // 4. Create panel. Add buttons to panel.

      Panel p1 = new Panel();
      for(int ii = 1; ii <= 2; ii++ )
          p1.add( buttons[ii-1] );

      // 5. Position canvas and panel within the frame.

      container.add( "South", p1 );
      container.add("Center", gs );
   }
}

/*
 *  =================================================================
 *  This class listens for action events associated with the buttons.
 *  =================================================================
 */

class ButtonAction implements ActionListener {
      private JButton b;
      private DemoGraphicsScreen gs;

      public ButtonAction ( JButton b, DemoGraphicsScreen gs ) {
         this.b  = b;
         this.gs = gs;
      }

      public void actionPerformed ( ActionEvent e ) {

         String s = new String(e.getActionCommand());
         System.out.println(s);

         if( s.compareTo("Clear") == 0 ) {
             gs.clear();
         }
         if( s.compareTo("Triangle") == 0 ) {
             gs.gsDraw();
         }
      }
}

/*
 *  ==============================================================
 *  This class listens for mouse events associated with the canvas
 *  ==============================================================
 */

class GraphicsListener implements MouseListener {
      private DemoGraphicsScreen gs;

      public GraphicsListener( DemoGraphicsScreen gs ) {
         this.gs = gs;
      }

      public void mouseReleased ( MouseEvent e ) {

          // Get and save new coordinates...

          gs.iXcoord = e.getX();
          gs.iYcoord = e.getY();

          // Print cursor coordinates and distance to triangle...

          gs.drawText();
      }

      public void mouseClicked ( MouseEvent e ) {};
      public void mouseEntered ( MouseEvent e ) {};
      public void mouseExited ( MouseEvent e ) {};
      public void mousePressed ( MouseEvent e ) {};
}

/*
 *  =======================
 *  Create graphics screen.
 *  =======================
 */

class DemoGraphicsScreen extends JPanel {
    int iXcoord, iYcoord;
    String cursorMessage   = null;
    String distanceMessage = null;
    Triangle t;

    private Dimension size;
    private Graphics    gs;

    // Constructor method

    public DemoGraphicsScreen() {

       t = new Triangle();
       t.node1 = new Node(); t.node2 = new Node(); t.node3 = new Node();

       t.node1.dX = 100.0; t.node1.dY = 100.0; t.node2.setName ("n1");
       t.node2.dX = 250.0; t.node2.dY = 100.0; t.node3.setName ("n2");
       t.node3.dX = 290.0; t.node3.dY = 300.0; t.node1.setName ("n3");
       t.edge1 = new Edge( "e1", t.node1, t.node2 );
       t.edge2 = new Edge( "e2", t.node2, t.node3 );
       t.edge3 = new Edge( "e3", t.node3, t.node1 );

    }

    //  Use the paint() method to display the (x,y) coordinates of the
    //  mouse when it is clicked...

    public void paint(Graphics g) {
       size = getSize();
       drawText();
    }

    // Draw cursor coordinates on the canvas ....

    public void drawText() {
       gs = getGraphics();
       Graphics2D g2D = (Graphics2D) gs;

       Node pt1 = new Node( iXcoord, iYcoord );

       // Display of cursor coordinates ....

       if ( cursorMessage != null ) {
          g2D.setColor( Color.white );
          g2D.drawString( cursorMessage, 15, getHeight()-50);
       }

       cursorMessage = "Cursor: " + iXcoord + ", " + iYcoord;
       g2D.setColor(Color.blue);
       g2D.drawString( cursorMessage, 15, getHeight()-50);

       // Display distance to triangle 

       if ( distanceMessage != null ) {
          g2D.setColor( Color.white );
          g2D.drawString( distanceMessage, 15, getHeight()-30);
       }

       distanceMessage = "Distance to triangle: " + t.distanceToPoint( pt1 );
       g2D.setColor(Color.blue);
       g2D.drawString( distanceMessage, 15, getHeight()-30);
    }
    
    // Get graphics and fill in background ....

    public void clear () {
        gs = getGraphics();
        Graphics2D g2D = (Graphics2D) gs;

        g2D.setColor( Color.white );
        g2D.fillRect( 0, 0, size.width-1, size.height-1 );
    }

    // Method to draw triangle ....

    public void gsDraw () {
        gs = getGraphics();
        Graphics2D g2D = (Graphics2D) gs;
 
        // Draw triangle nodes and edges ....

        g2D.setColor( Color.blue );
        g2D.drawLine ( (int) t.node1.dX, (int) t.node1.dY,
                       (int) t.node2.dX, (int) t.node2.dY );
        g2D.drawLine ( (int) t.node2.dX, (int) t.node2.dY,
                       (int) t.node3.dX, (int) t.node3.dY );
        g2D.drawLine ( (int) t.node1.dX, (int) t.node1.dY,
                       (int) t.node3.dX, (int) t.node3.dY );

        g2D.fillRect( (int) (t.node1.dX-3), (int) (t.node1.dY-3), 6, 6);
        g2D.fillRect( (int) (t.node2.dX-3), (int) (t.node2.dY-3), 6, 6);
        g2D.fillRect( (int) (t.node3.dX-3), (int) (t.node3.dY-3), 6, 6);
    }
}