/**
 * @version 1.20 27 Jun	1998
 * @author Cay Horstmann
 */

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

class ChartPanel extends JPanel
{  public ChartPanel(double[] v, String[] n, String t)
   {  names = n;
      values = v;
      title = t;
   }

   public void paintComponent(Graphics g)
   {  super.paintComponent(g);
      if (values == null || values.length == 0)	return;
      int i;
      double minValue =	0;
      double maxValue =	0;
      for (i = 0; i < values.length; i++)
      {	 if (minValue >	values[i]) minValue = values[i];
	 if (maxValue <	values[i]) maxValue = values[i];
      }

      Dimension	d = getSize();
      int clientWidth =	d.width;
      int clientHeight = d.height;
      int barWidth = clientWidth / values.length;

      Font titleFont
	 = new Font("SansSerif", Font.BOLD, 20);
      FontMetrics titleFontMetrics
	 = g.getFontMetrics(titleFont);
      Font labelFont
	 = new Font("SansSerif", Font.PLAIN, 10);
      FontMetrics labelFontMetrics
	 = g.getFontMetrics(labelFont);

      int titleWidth
	 = titleFontMetrics.stringWidth(title);
      int y = titleFontMetrics.getAscent();
      int x = (clientWidth - titleWidth) / 2;
      g.setFont(titleFont);
      g.drawString(title, x, y);

      int top =	titleFontMetrics.getHeight();
      int bottom = labelFontMetrics.getHeight();
      if (maxValue == minValue)	return;
      double scale = (clientHeight - top - bottom)
	 / (maxValue - minValue);
      y	= clientHeight - labelFontMetrics.getDescent();
      g.setFont(labelFont);

      for (i = 0; i < values.length; i++)
      {	 int x1	= i * barWidth + 1;
	 int y1	= top;
	 int height = (int)(values[i] *	scale);
	 if (values[i] >= 0)
	    y1 += (int)((maxValue - values[i]) * scale);
	 else
	 {  y1 += (int)(maxValue * scale);
	    height = -height;
	 }

	 g.setColor(Color.red);
	 g.fillRect(x1,	y1, barWidth - 2, height);
	 g.setColor(Color.black);
	 g.drawRect(x1,	y1, barWidth - 2, height);
	 int labelWidth
	    = labelFontMetrics.stringWidth(names[i]);
	 x = i * barWidth + (barWidth -	labelWidth) / 2;
	 g.drawString(names[i],	x, y);
      }
   }

   private double[] values;
   private String[] names;
   private String title;
}

public class Chart extends JApplet
{  public void init()
   {  String v = getParameter("values");
      if (v == null) return;
      int n = Integer.parseInt(v);
      double[] values =	new double[n];
      String[] names = new String[n];
      int i;
      for (i = 0; i < n; i++)
      {	 values[i] = Double.parseDouble
	    (getParameter("value_" + (i	+ 1)));
	 names[i] = getParameter("name_" + (i +	1));
      }

      Container	contentPane = getContentPane();
      contentPane.add(new ChartPanel(values, names,
	 getParameter("title")));
   }
}