//  WaveShower.java
//
/*************************************************************************
 *                                                                       *
 * Copyright (c) 1999     Northwestern University                        *
 *                                                                       *
 * This program is free software.  You can copy, modify, or redistribute *
 * this software under the terms of the GNU General Public License       *
 * as published by the Free Software Foundation; either version 2 of the *
 * License, or (at your option) any later version, provided that both    *
 * the above copyright notice appears in all copies and that this        *
 * permission notice appear in any supporting documentation.             *
 *                                                                       *
 * This software is provided "as is" in the hope that it will be useful, *
 * but WITHOUT any expressed or implied warranty of merchantability or   *
 * fitness for any particular purpose.  Your mileage may vary.           * 
 * See the GNU General Public License for more details.                  *
 *                                                                       *
 *************************************************************************/

//  Modification History
//    Date      Initials     Change
/*
 * @author Northwestern University
 * @version 0.1, June 1999
 */

import java.awt.*;
import java.applet.Applet;
import java.awt.event.*;
import Banner;

class WaveCanvas extends Canvas implements Runnable{
	WaveShower	waveshower;
	Thread 		wavethread;
	int 			waveindex = 0;
	int 			time = 0;
	Dimension		d;
	int[]			x, y;
	Image 		offImage;
	Graphics 		og;
	final double 	pi = 3.1415;

	WaveCanvas(WaveShower waveshower){
		this.waveshower = waveshower;
	}

	public void run(){
		while(wavethread != null){
			repaint();
			time++;
			try{
			Thread.sleep(60);
			}catch(InterruptedException e){
			break;
			}
		}
	}

	public void start(){
		prepareImage();
		if(wavethread == null){
			wavethread = new Thread(this);
			wavethread.start();
		}
	}

	public void stop(){
		wavethread = null;
		time = 0;
	}

	public void paint(Graphics g){
		if (waveindex != 0){
			g.setColor(Color.red);
			g.drawLine(10, d.height/2, d.width-10, d.height/2);
			g.setColor(Color.black);
			g.drawLine(d.width-10, d.height/4, d.width-10, d.height*3/4);
		}	
	}		

	private void myPaint(Graphics g){
		g.drawImage(offImage, 0, 0, null);
		}

	private void paintImage(Graphics g){
	//	setBackground(Color.blue);
		g.setColor(Color.red);
		g.clearRect(0, 0, d.width, d.height);
		if ((waveindex != 0)){
			int i;
			for (i = 0; i <waveindex; i++){
				g.drawLine(x[i], y[i], x[i+1], y[i+1]);
			}
			g.setColor(Color.black);
			g.drawLine(x[waveindex], d.height/4, x[waveindex], 
				d.height*3/4);
		}
	}

	public synchronized void update(Graphics g){
		d = getSize();
		waveindex = (d.width-20);
		x = new int[waveindex+1];
		y = new int[waveindex+1];
		int i;
		if (!waveshower.on){
			g.clearRect(0, 0, d.width, d.height);
			paint(g);
			return;			
		}else{
			for(i = 0; i <=waveindex; i++){
				x[i] = i + 10;
			}
			if (waveshower.waveshape){//if ..shape
				if(waveshower.waveend){//if .. end
					for(i = 0; i <=waveindex; i++){//for loop
						if((float )x[i] >= waveshower.f*time*waveshower.length/(20*pi))//if time
							{y[i] = d.height/2;}
						else{if ((waveshower.f*time*waveshower.length/(20*pi)>=d.width-10.0)&&
								((float )x[i] >= 2*d.width -20.0 
								-waveshower.f*time*waveshower.length/(20*pi))) {
							y[i] = (int )(d.height/2 + 
							50*Math.sin(2*pi*x[i]/waveshower.length - 
							waveshower.f * time/10.0)-
							50*Math.sin(2*pi*(2*d.width-20-x[i])/waveshower.length
							- waveshower.f*time/10.0));}
							else{y[i] = (int)(d.height/2 +
								50*Math.sin(2*pi*x[i]/waveshower.length -
								waveshower.f*time/10.0));}
							}//if time
						}//for loop
					}
					else{for(i = 0; i <=waveindex; i++){//for loop
						if((float )x[i] >= waveshower.f*time*waveshower.length/(20*pi))//if time
							{y[i] = d.height/2;}
						else{if ((waveshower.f*time*waveshower.length/(20*pi)>=d.width-10.0)&&
							((float )x[i] >= 2*d.width -20.0 
								-waveshower.f*time*waveshower.length/(20*pi))){
							y[i] = (int )(d.height/2 + 
							50*Math.sin(2*pi*x[i]/waveshower.length - 
							waveshower.f * time/10.0)+
							50*Math.sin(2*pi*(2*d.width-20-x[i])/waveshower.length
							- waveshower.f*time/10.0));}
							else{y[i] = (int)(d.height/2 +
								50*Math.sin(2*pi*x[i]/waveshower.length -
								waveshower.f*time/10.0));}
							}//if time
						}//for .. loop
					}//if .. end
				}
			else{if(waveshower.waveend){//if .. end
					for(i = 0; i <=waveindex; i++){//for loop
						if(waveshower.f*time*waveshower.length/(20*pi)<=d.width-10.0){
							if(((float )x[i] >= waveshower.f*time*waveshower.length/(20*pi))
								|| ((float )x[i] <= waveshower.f*time*waveshower.length/(20*pi)
								-waveshower.length))//if time
								{y[i] = d.height/2;}
							else{y[i] = (int )(d.height/2 + 
								50*Math.sin(2*pi*x[i]/waveshower.length -
								waveshower.f*time/10.0));}}
						else{if ((waveshower.f*time*waveshower.length/(20*pi)>=d.width - 10.0)
							&& (waveshower.f*time*waveshower.length/(20*pi)<=d.width - 10.0 + 
							waveshower.length)){
								if(((float )x[i] >= 2*d.width -20.0  -
									waveshower.f*time*waveshower.length/(20*pi))&&
									((float )x[i] >= 
										waveshower.f*time*waveshower.length/(20*pi)-
										waveshower.length)){
										y[i] = (int )(d.height/2 + 
										50*Math.sin(2*pi*x[i]/waveshower.length - 
										waveshower.f * time/10.0)-
										50*Math.sin(2*pi*(2*d.width-20-x[i])/waveshower.length
										- waveshower.f*time/10.0));}
								if(((float )x[i] <= 2*d.width -20.0  -
									waveshower.f*time*waveshower.length/(20*pi))&&
									((float )x[i] >= 
										waveshower.f*time*waveshower.length/(20*pi)-
										waveshower.length)){
										y[i] = (int)(d.height/2 + 
										50*Math.sin(2*pi*x[i]/waveshower.length - 
										waveshower.f * time/10.0));}
								 if(((float )x[i] >= 2*d.width -20.0  -
									waveshower.f*time*waveshower.length/(20*pi))&&
									((float )x[i] <= 
										waveshower.f*time*waveshower.length/(20*pi)-
										waveshower.length)){
										y[i] = (int) (d.height/2 -
										50*Math.sin(2*pi*(2*d.width-20-x[i])/waveshower.length
										- waveshower.f*time/10.0));}
								if(((float )x[i] <= 2*d.width -20.0  -
									waveshower.f*time*waveshower.length/(20*pi))&&
									((float )x[i] <= 
										waveshower.f*time*waveshower.length/(20*pi)-
										waveshower.length)){
										y[i] = (int )d.height/2;}}
							if (waveshower.f*time*waveshower.length/(20*pi)>=d.width - 10.0 + 
							waveshower.length){
								if(waveshower.f*time*waveshower.length/(20*pi)<=
								2*(d.width-10)+ waveshower.length){
									if(((float )x[i] <=2*(d.width-10) - 
									waveshower.f*time*waveshower.length/(20*pi))
									|| ((float )x[i] >= 2*d.width-20 -
									waveshower.f*time*waveshower.length/(20*pi)+
										waveshower.length)){
										y[i] = (int )d.height/2;}
									else{
										y[i] = (int)(d.height/2 -
										50*Math.sin(2*pi*(2*d.width-20-x[i])/waveshower.length -
										waveshower.f*time/10.0));}
									}
								else{time = -1;
									y[i] = (int )d.height/2;}
								}
							}//if time
						}//for loop
					}
					else{for(i = 0; i <=waveindex; i++){//for loop
						if(waveshower.f*time*waveshower.length/(20*pi)<=d.width-10.0){
							if(((float )x[i] >= waveshower.f*time*waveshower.length/(20*pi))
								|| ((float )x[i] <= waveshower.f*time*waveshower.length/(20*pi)
								-waveshower.length))//if time
								{y[i] = d.height/2;}
							else{y[i] = (int )(d.height/2 + 
								50*Math.sin(2*pi*x[i]/waveshower.length -
								waveshower.f*time/10.0));}}
						else{if ((waveshower.f*time*waveshower.length/(20*pi)>=d.width - 10.0)
							&& (waveshower.f*time*waveshower.length/(20*pi)<=d.width - 10.0 + 
							waveshower.length)){
								if(((float )x[i] >= 2*d.width -20.0  -
									waveshower.f*time*waveshower.length/(20*pi))&&
									((float )x[i] >= 
										waveshower.f*time*waveshower.length/(20*pi)-
										waveshower.length)){
										y[i] = (int )(d.height/2 + 
										50*Math.sin(2*pi*x[i]/waveshower.length - 
										waveshower.f * time/10.0)+
										50*Math.sin(2*pi*(2*d.width-20-x[i])/waveshower.length
										- waveshower.f*time/10.0));}
								if(((float )x[i] <= 2*d.width -20.0  -
									waveshower.f*time*waveshower.length/(20*pi))&&
									((float )x[i] >= 
										waveshower.f*time*waveshower.length/(20*pi)-
										waveshower.length)){
										y[i] = (int)(d.height/2 + 
										50*Math.sin(2*pi*x[i]/waveshower.length - 
										waveshower.f * time/10.0));}
								 if(((float )x[i] >= 2*d.width -20.0  -
									waveshower.f*time*waveshower.length/(20*pi))&&
									((float )x[i] <= 
										waveshower.f*time*waveshower.length/(20*pi)-
										waveshower.length)){
										y[i] = (int) (d.height/2 +
										50*Math.sin(2*pi*(2*d.width-20-x[i])/waveshower.length
										- waveshower.f*time/10.0));}
								if(((float )x[i] <= 2*d.width -20.0  -
									waveshower.f*time*waveshower.length/(20*pi))&&
									((float )x[i] <= 
										waveshower.f*time*waveshower.length/(20*pi)-
										waveshower.length)){
										y[i] = (int )d.height/2;}}
							if (waveshower.f*time*waveshower.length/(20*pi)>=d.width - 10.0 + 
							waveshower.length){
								if(waveshower.f*time*waveshower.length/(20*pi)<=
								2*(d.width-10)+ waveshower.length){
									if(((float )x[i] <=2*(d.width-10) - 
									waveshower.f*time*waveshower.length/(20*pi))
									|| ((float )x[i] >= 2*d.width-20 -
									waveshower.f*time*waveshower.length/(20*pi)+
										waveshower.length)){
										y[i] = (int )d.height/2;}
									else{
										y[i] = (int)(d.height/2 +
										50*Math.sin(2*pi*(2*d.width-20-x[i])/waveshower.length -
										waveshower.f*time/10.0));}
									}
								else{time = -1;
									y[i] = (int )d.height/2;}
								}
							}//if time
						}//for loop

					}//if .. end
				}//if ..shape
			}				
		paintImage(og);	
		myPaint(g);
	}

	private void prepareImage(){
		offImage = createImage(d.width, d.height);
		og 	= offImage.getGraphics();
	}

}

public class WaveShower extends Applet implements ActionListener, ItemListener{
	WaveCanvas		wavecanvas;
	Panel			control, choicecontrol, subpanel1, subpanel2;
	Button		wavebutton;
	Label			label1, label2;
	TextField		text1, text2;
	Choice		c1, c2;
	int 			length, f;
	boolean		waveshape, waveend, on;	

	public void init(){
	  length = 100;
	  f = 10;
	  waveshape = true;
	  waveend = true;
	  on = false;
	  BorderLayout layout = new BorderLayout();
	  layout.setVgap(5);
	  layout.setHgap(10);
	  setLayout(layout);

	  add("North", new Banner("Wave Reflection"));	  
	  wavecanvas = new WaveCanvas(this);
	  add("Center", wavecanvas);
	  
	  control = new Panel();
	  add("South", control);
	  
	  label1 = new Label("Wave Length");
	  label2 = new Label("Frequency");
	  text1 = new TextField("100", 3);
	  text2 = new TextField("10", 3);
	  wavebutton = new Button("Start");
	  c1 = new Choice();
	  c1.addItem("Harmonic Wave");
	  c1.addItem("Single Pulse");
	  c2 = new Choice();
	  c2.addItem("Fixed end");
	  c2.addItem("Open end");
	  
	  control.setLayout(new FlowLayout(FlowLayout.LEFT));
	  control.add(label1);
	  control.add(text1); text1.addActionListener(this);
	  control.add(label2);
	  control.add(text2); text2.addActionListener(this);
	  control.add(c1);	c1.addItemListener(this);
	  control.add(c2);	c2.addItemListener(this);
	  control.add(wavebutton); wavebutton.addActionListener(this);
	}

  public void start(){
  }

  public void paint(Graphics g){
    wavebutton.requestFocus();
    wavecanvas.repaint();
  }
  public void actionPerformed(ActionEvent e){
    Object src = e.getSource();
    
    if(src == wavebutton){
      on ^= true;
      if (on){
	wavebutton.setForeground(Color.red);
	wavebutton.setLabel("Stop");
	wavecanvas.start();
      }else{wavebutton.setForeground(Color.black);
      wavebutton.setLabel("Start");
      wavecanvas.stop();
      wavecanvas.repaint();
      }
    }
    if(src == text1){
      length = Float.valueOf(text1.getText()).intValue();
    }
    if(src == text2){
      f = Float.valueOf(text2.getText()).intValue();
    }
    
  }
  public void itemStateChanged(ItemEvent e){
    Object src = e.getSource();
    int id;
    
    if(src == c1){
      id = c1.getSelectedIndex();
      if (c1.getItem(id) == "Harmonic Wave"){	
	waveshape = true;
      }else{waveshape = false;}
    }					
    if(src == c2){
      id = c2.getSelectedIndex();
      if (c2.getItem(id) == "Fixed end"){
	waveend = true;
      }else{waveend = false;}
    }
  }
  
  public String getAppletInfo(){
    return "Xiaowei Jiang, not copyrighted, Feb. 1999";
  }
}