    001/*
    002 * Licensed to the Apache Software Foundation (ASF) under one or more
    003 * contributor license agreements.  See the NOTICE file distributed with
    004 * this work for additional information regarding copyright ownership.
    005 * The ASF licenses this file to You under the Apache License, Version 2.0
    006 * (the "License"); you may not use this file except in compliance with
    007 * the License.  You may obtain a copy of the License at
    008 *
    009 *      http://www.apache.org/licenses/LICENSE-2.0
    010 *
    011 * Unless required by applicable law or agreed to in writing, software
    012 * distributed under the License is distributed on an "AS IS" BASIS,
    013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    014 * See the License for the specific language governing permissions and
    015 * limitations under the License.
    016 */
    017package org.apache.commons.imaging.palette;
    018
    019import java.io.Serializable;
    020import java.util.Comparator;
    021
    022/**
    023 * A comparator for {#link ColorCount} elements.
    024 *
    025 * <p>It uses a given {#link ColorComponent} to choose what
    026 * channel must be used for the comparison.</p>
    027 *
    028 * <p>For example, if the comparator is created for the
    029 * {@code ColorComponent.RED} channel, then it will
    030 * compare the value of red of each {@code ColorCount}
    031 * object in the array of elements.</p>
    032 *
    033 * @since 1.0-alpha2
    034 */
    035public class ColorCountComparator implements Comparator<ColorCount>, Serializable {
    036    private static final long serialVersionUID = 1L;
    037    /**
    038     * Color component used during the comparison.
    039     */
    040    private ColorComponent colorComponent;
    041
    042    public ColorCountComparator(final ColorComponent colorComponent) {
    043        this.colorComponent = colorComponent;
    044    }
    045
    046    @Override
    047    public int compare(ColorCount c1, ColorCount c2) {
    048        switch (colorComponent) {
    049        case ALPHA:
    050            return c1.alpha - c2.alpha;
    051        case RED:
    052            return c1.red - c2.red;
    053        case GREEN:
    054            return c1.green - c2.green;
    055        case BLUE:
    056            return c1.blue - c2.blue;
    057        default:
    058            return 0;
    059        }
    060    }
    061
    062}