ColorSource.java

/* ===========================================================
 * Orson Charts : a 3D chart library for the Java(tm) platform
 * ===========================================================
 * 
 * (C)opyright 2013-2016, by Object Refinery Limited.  All rights reserved.
 * 
 * http://www.object-refinery.com/orsoncharts/index.html
 * 
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 * 
 * [Oracle and Java are registered trademarks of Oracle and/or its affiliates. 
 * Other names may be trademarks of their respective owners.]
 * 
 * If you do not wish to be bound by the terms of the GPL, an alternative
 * commercial license can be purchased.  For details, please see visit the
 * Orson Charts home page:
 * 
 * http://www.object-refinery.com/orsoncharts/index.html
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 */

package com.orsoncharts.plot;

import java.awt.Color;

/**
 * A color source for use by the {@link PiePlot3D} class.  This is the 
 * interface through which the plot will obtain colors for each data item 
 * (segment) in the chart.  A default implementation
 * ({@link StandardColorSource}) is provided.
 */
public interface ColorSource<K extends Comparable<K>> {

    /**
     * Returns the color for one data item in the chart.  We return a 
     * {@code Color} rather than a paint, because some manipulations
     * that require a {@code Color} instance are done for the shading 
     * during the 3D rendering.
     * 
     * @param key  the key ({@code null} not permitted).
     * 
     * @return The color.
     */
    Color getColor(K key);
    
    /**
     * Sets the color associated with the specified key.  If the supplied
     * color is {@code null}, this will have the effect of clearing any
     * previous setting and reverting to the default color.
     * 
     * @param key  the key ({@code null} not permitted).
     * @param color  the color ({@code null} permitted).
     */
    void setColor(K key, Color color);
    
    /**
     * Restyles the source using the specified colors.  Refer to the 
     * implementing class to confirm the precise behaviour (typically all 
     * existing color settings are cleared and the specified colors are 
     * installed as the new defaults).
     * 
     * @param colors  the colors.
     * 
     * @since 1.2
     */
    void style(Color... colors);
  
}