// Histogram class
// Dave Reed
// 11/10/01
//////////////////////////////////////////

import java.awt.*;
import java.applet.*;
import java.util.Vector;

public class Histogram extends Applet
{
  private int WIDTH, HEIGHT;
  private Image offScreenImage;
  private Graphics offScreenGraphics;

  public void init()
  {
    Dimension dim = getSize();
    WIDTH = dim.width;
    HEIGHT = dim.height;
  }

  private Vector Vectorize(String str)
  {
    Vector items = new Vector();

    while (str.length() > 0) {
      int index = 0;
      while (index < str.length() &&
             Character.isWhitespace(str.charAt(index))) {
        index++;
      }

      if (index < str.length()) {
        String item = "";
        while (index < str.length() &&
               !Character.isWhitespace(str.charAt(index))) {
          item += str.charAt(index);
          index++;
        }
        items.addElement(item);
      }

      if (index < str.length()) {
        str = str.substring(index+1, str.length());
      }
      else {
        str = "";
      }
    }
    return items;
  }

  public void drawHistogram(String dataString)
  {
    Vector data = Vectorize(dataString);

	if (data.size() > 1) {
	  offScreenImage = createImage(WIDTH, HEIGHT);
	  offScreenGraphics = offScreenImage.getGraphics();
	
	  int max = Integer.parseInt((String)data.elementAt(1));
	  for (int i = 3; i < data.size(); i+=2) {
		if (Integer.parseInt((String)data.elementAt(i)) > max) {
		  max = Integer.parseInt((String)data.elementAt(i));
		}
	  }

	  int barHeight = (int)(2.0*HEIGHT/data.size());
	  
	  for (int i = 0; i < data.size(); i+=2) {
		int value = Integer.parseInt((String)data.elementAt(i+1));
	    int barWidth = (WIDTH*value)/max;
	    offScreenGraphics.setColor(Color.yellow);
	    offScreenGraphics.fillRect(0, barHeight*i/2, barWidth, barHeight);
	    offScreenGraphics.setColor(Color.black);
	    offScreenGraphics.drawRect(0, barHeight*i/2, barWidth, barHeight);
	    offScreenGraphics.drawString(data.elementAt(i)+
		                             "  ("+ value +")",
		  	                         5, (i+1)*barHeight/2); 
	  }

	  paint(getGraphics());
	}
  }

  public void paint(Graphics g)
  {
    g.drawImage(offScreenImage, 0, 0, null);
  }
}