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.internal;
018
019import java.io.IOException;
020import java.util.function.Predicate;
021import java.util.function.Supplier;
022
023import org.apache.commons.imaging.AbstractImageParser;
024import org.apache.commons.imaging.ImageFormat;
025import org.apache.commons.imaging.ImageFormats;
026import org.apache.commons.imaging.Imaging;
027import org.apache.commons.imaging.ImagingParameters;
028import org.apache.commons.imaging.bytesource.ByteSource;
029
030/**
031 * Internal utilities.
032 *
033 * @since 1.0-alpha3
034 */
035public final class ImageParserFactory {
036
037    public static <T extends ImagingParameters<T>> AbstractImageParser<T> getImageParser(final ByteSource byteSource) throws IOException {
038        // TODO: circular dependency between Imaging and internal Util class below.
039        final ImageFormat format = Imaging.guessFormat(byteSource);
040        if (!format.equals(ImageFormats.UNKNOWN)) {
041            return ImageParserFactory.getImageParser(format);
042        }
043
044        final String fileName = byteSource.getFileName();
045        if (fileName != null) {
046            return ImageParserFactory.getImageParser(fileName);
047        }
048
049        throw new IllegalArgumentException("Can't parse this format.");
050    }
051
052    public static <T extends ImagingParameters<T>> AbstractImageParser<T> getImageParser(final ImageFormat format) {
053        return getImageParser(parser -> parser.canAcceptType(format), () -> new IllegalArgumentException("Unknown ImageFormat: " + format));
054    }
055
056    // This generics suppression is as good as the predicate given. If the predicate violates a generics design,
057    // then there will be an error during runtime.
058    @SuppressWarnings("unchecked")
059    private static <T extends ImagingParameters<T>> AbstractImageParser<T> getImageParser(final Predicate<AbstractImageParser<?>> pred,
060            final Supplier<? extends RuntimeException> supplier) {
061        return (AbstractImageParser<T>) AbstractImageParser.getAllImageParsers().stream().filter(pred).findFirst().orElseThrow(supplier);
062    }
063
064    public static <T extends ImagingParameters<T>> AbstractImageParser<T> getImageParser(final String fileExtension) {
065        return getImageParser(parser -> parser.canAcceptExtension(fileExtension), () -> new IllegalArgumentException("Unknown extension: " + fileExtension));
066    }
067
068    private ImageParserFactory() {
069    }
070}