/* PictureTime.java - This example illustrates the hierarchical use
 *  of components in a grid layout.
 *  This version uses Java 1.1 event model.
 * New Version with colored circles on the canvas by Mehmet Sen 10/97.
 */

import java.awt.*;
import java.awt.event.*;

public class PictureTime extends java.applet.Applet {

/* instance variable to hold the subpanel component */  
  ControlPanel control;

/* instance variable to hold the canvas component */
  Display displaycanvas;


  public void init() {  
    
  /* using grid layout with gap of 15 points separating each component */
    setLayout(new BorderLayout(5,0)); 
   
    displaycanvas = new Display(0);  /* creating the canvas component */
    displaycanvas.setBackground(Color.blue); 
    displaycanvas.start();
    
  /* creating instance for PictureControl panel */
    control = new ControlPanel(this);

  /* adding the components to the panel */
    add(displaycanvas,BorderLayout.CENTER);  
    add(control,BorderLayout.EAST);
  }

  
  void changeCanvasColor(String category) {
    if (category.equals("Button 1")) 
                displaycanvas.draw(1,Color.green);
    else if (category.equals("Button 2")) 
                displaycanvas.draw(2,Color.cyan);
    else if (category.equals("Button 3")) 
                displaycanvas.draw(3,Color.pink);
    else displaycanvas.draw(0,Color.black);
  }
}







/* this class is a subclass of Panel */

class ControlPanel extends Panel implements ActionListener
{ 
/* instance variable to hold a pointer to calling class */
  PictureTime outerparent;

/* the three control buttons */
  Button b1,b2,b3;   
  
  ControlPanel(PictureTime target) {
    this.outerparent = target;
    setLayout(new BorderLayout(0,140));
    
    /* putting the buttons */
    setBackground(Color.lightGray);
    
    b1=new Button("Button 1");
    add(b1,BorderLayout.NORTH);
    b1.setForeground(Color.black);
    b1.setBackground(Color.green);
    b1.addActionListener(this);

    b2=new Button("Button 2");
    add(b2,BorderLayout.CENTER);
    b2.setForeground(Color.blue);
    b2.setBackground(Color.cyan);
    b2.addActionListener(this);

    b3=new Button("Button 3");
    add(b3,BorderLayout.SOUTH);
    b3.setForeground(Color.black);
    b3.setBackground(Color.pink);
    b3.addActionListener(this);

  }
  
  public void actionPerformed(ActionEvent evt) {
/* getActionCommand will return label of the button clicked
   or we could have used getSource() to return pointer to the button,
   i.e. either t, d, or s */
    String label = evt.getActionCommand();
    this.outerparent.changeCanvasColor(label);
  }
}


// Display canvas show animated little balls from left towards pressed buton
class Display extends Canvas implements Runnable 
{
  int Target;
  Thread animate;
  Display(int _target)
  {
    Target=_target;
  }
  public void draw(int _target,Color bg)  {
    setBackground(bg);
    Target=_target;
    repaint();
  }
  public void start()  {
    if (animate==null){
      animate=new Thread(this);
      animate.start();
    }
  }
  public void stop()  {
    if (animate!=null){
      animate.stop();
      animate=null;
    }
  }
  
  public void run()   {
    while(true){
      try {
	Thread.sleep(100);
      }
      catch (InterruptedException e) {
      }
      repaint();
    }
  }

  public void paint(Graphics g) 
  {
    int X,Y,source_x,source_y,target_x,target_y;
    int h=20;
    int w=20;
    int i=0;
    int wstep=h*4/3;
    int hstep=h*4/3;
    X=getSize().width;
    Y=getSize().height;
    source_x=0;
    source_y=Y/3;
    target_x=X;
    if (Target==1 ) 
      target_y=5;
    else if (Target==2) 
       target_y=Y/2;
    else if (Target==3) 
       target_y=Y-20;
    else {
      target_x=X/2;
      target_y=-50;
    }
    
    for (i=source_x;i<X/4;i+=wstep+8){
      g.setColor(Color.black);
      g.fillOval(i-5,source_y-5,w+10,h+10);
      g.setColor(new Color((float)Math.random(),(float)Math.random(),(float)Math.random()));
      g.fillOval(i,source_y,w,h);
    }
    for (int x=i,y=source_y;x<target_x;){
      g.setColor(Color.black);
      g.fillOval(x-5,y-5,w+10,h+10);
      g.setColor(new Color((float)Math.random(),(float)Math.random(),(float)Math.random()));
      g.fillOval(x,y,w,h);
      if(x<target_x) x+=wstep;
      if((y<target_y+10)&&(y>target_y-10)) x+=8;
      else if(y<target_y) y+=hstep;
      else y-=hstep;
    }
  }
  
}