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