    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 */
    017
    018package org.apache.commons.imaging.formats.png;
    019
    020import java.util.Arrays;
    021
    022public enum PngColorType {
    023
    024    // FIXME can this be merged with ImageInfo.ColorType?
    025
    026    GREYSCALE(0, true, false, 1, new int[] { 1, 2, 4, 8, 16 }), TRUE_COLOR(2, false, false, 3, new int[] { 8, 16 }),
    027    INDEXED_COLOR(3, false, false, 1, new int[] { 1, 2, 4, 8 }), GREYSCALE_WITH_ALPHA(4, true, true, 2, new int[] { 8, 16 }),
    028    TRUE_COLOR_WITH_ALPHA(6, false, true, 4, new int[] { 8, 16 });
    029
    030    static PngColorType getColorType(final boolean alpha, final boolean grayscale) {
    031        if (grayscale) {
    032            if (alpha) {
    033                return GREYSCALE_WITH_ALPHA;
    034            }
    035            return GREYSCALE;
    036        }
    037        if (alpha) {
    038            return TRUE_COLOR_WITH_ALPHA;
    039        }
    040        return TRUE_COLOR;
    041    }
    042
    043    public static PngColorType getColorType(final int value) {
    044        for (final PngColorType type : values()) {
    045            if (type.value == value) {
    046                return type;
    047            }
    048        }
    049
    050        return null;
    051    }
    052
    053    private final int value;
    054    private final boolean greyscale;
    055    private final boolean alpha;
    056
    057    private final int samplesPerPixel;
    058
    059    private final int[] allowedBitDepths;
    060
    061    PngColorType(final int value, final boolean greyscale, final boolean alpha, final int samplesPerPixel, final int[] allowedBitDepths) {
    062        this.value = value;
    063        this.greyscale = greyscale;
    064        this.alpha = alpha;
    065        this.samplesPerPixel = samplesPerPixel;
    066        this.allowedBitDepths = allowedBitDepths;
    067    }
    068
    069    int getSamplesPerPixel() {
    070        return samplesPerPixel;
    071    }
    072
    073    int getValue() {
    074        return value;
    075    }
    076
    077    boolean hasAlpha() {
    078        return alpha;
    079    }
    080
    081    boolean isBitDepthAllowed(final int bitDepth) {
    082        return Arrays.binarySearch(allowedBitDepths, bitDepth) >= 0;
    083    }
    084
    085    boolean isGreyscale() {
    086        return greyscale;
    087    }
    088}