package net.sf.statcvs.charts;

 import java.awt.Color;

 /**

  * Utility class for chart related stuff.

  * 

  * @author Richard Cyganiak

  * @version $Id: ChartUtils.java,v 1.3 2008/04/02 11:22:15 benoitx Exp $

  */

 public class ChartUtils {

     private static final String MAGIC_SEED_1 = "0 Ax-!";

     private static final String MAGIC_SEED_2 = "!Z x5";

     private ChartUtils() {

         // Only static methods

     }

     /**

      * Returns a distinct <code>Color</code> for a <code>String</code> argument.

      * The algorithm tries to provide different colors for similar strings, and

      * will return equal colors for equal strings. The colors will all have

      * similar brightness and maximum intensity. Useful for chart coloring.

      * @param s a <code>String</code> to get a color for

      * @return a distinct <code>Color</code> for a <code>String</code> argument.

      * The algorithm tries to provide different colors for similar strings, and

      * will return equal colors for equal strings. The colors will all have

      * similar brightness and maximum intensity. Useful for chart coloring.

      */

     public static Color getStringColor(final String s) {

         double d = (MAGIC_SEED_1 + s + MAGIC_SEED_2).hashCode();

         d -= Integer.MIN_VALUE;

         d /= ((double) Integer.MAX_VALUE - (double) Integer.MIN_VALUE);

         d *= 3;

         // Now 0 <= d < 3

         if (d < 1) {

             final int r = (int) ((1 - d) * MAX_RED);

             final int g = (int) (d * MAX_GREEN);

             return new Color(r, g, 0);

         } else if (d < 2) {

             final int g = (int) ((2 - d) * MAX_GREEN);

             final int b = (int) ((d - 1) * MAX_BLUE);

             return new Color(0, g, b);

         } else {

             final int r = (int) ((d - 2) * MAX_RED);

             final int b = (int) ((3 - d) * MAX_BLUE);

             return new Color(r, 0, b);

         }

     }

     // Use values less than 256 here, or the colors will get too bright

     private static double MAX_RED = 200;

     private static double MAX_GREEN = 150;

     private static double MAX_BLUE = 250;

 }