package sim.util.gui;import java.awt.*;/** * ColorMap is a interface for mapping numerical values to colors. * The easiest way to implement getRGB(level) is simply with getColor(level).getRGB(). * validLevel indicates whether the numerical value is within a range that seems "reasonable" * for coding into colors -- however ColorMap should provide *some* feasible color for * *any* given value, including NaN.  defaultValue() provides a default numerical value * within the "reasonable" range -- often the minimum value.  It must be the case that * validLevel(defaultValue()) == true. * * @author Gabriel Catalin Balan *  */public interface ColorMap     {    /** Returns a color for the given level */    public Color getColor(double level);    /** Returns the RGB values, plus alpha, for a color for the given level.  The byte ordering should be in the same fashion that Color.getRGB() is provided. */    public int getRGB(double level);    /** Returns the alpha value for a color for the given level.  This could be simply written as                     <p><code>return getRGB(level) >>> 24 ; </code>                    <p>...or it could be written as:                    <p><code>return getColor(level).getAlpha() </code>                    <p>...however it's likely that it thie method could be written more efficiently than either of these.    */    public int getAlpha(double level);    /** Returns true if a level is "valid" (it provides a meaningful color) */    public boolean validLevel(double level);    /** Returns <i>some</i> level which is valid (that is, validLevel(defaultValue()) should        always return true).  This is commonly provided to give the user a level to replace        an "invalid" level he's typed in. */    public double defaultValue();    }