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.text.translate;
018
019import java.io.IOException;
020import java.io.Writer;
021import java.util.ArrayList;
022import java.util.List;
023import java.util.Objects;
024import java.util.stream.Stream;
025
026/**
027 * Executes a sequence of translators one after the other. Execution ends whenever
028 * the first translator consumes code points from the input.
029 *
030 * @since 1.0
031 */
032public class AggregateTranslator extends CharSequenceTranslator {
033
034    /**
035     * Translator list.
036     */
037    private final List<CharSequenceTranslator> translators = new ArrayList<>();
038
039    /**
040     * Specify the translators to be used at creation time.
041     *
042     * @param translators CharSequenceTranslator array to aggregate
043     */
044    public AggregateTranslator(final CharSequenceTranslator... translators) {
045        if (translators != null) {
046            Stream.of(translators).filter(Objects::nonNull).forEach(this.translators::add);
047        }
048    }
049
050    /**
051     * The first translator to consume code points from the input is the 'winner'.
052     * Execution stops with the number of consumed code points being returned.
053     * {@inheritDoc}
054     */
055    @Override
056    public int translate(final CharSequence input, final int index, final Writer writer) throws IOException {
057        for (final CharSequenceTranslator translator : translators) {
058            final int consumed = translator.translate(input, index, writer);
059            if (consumed != 0) {
060                return consumed;
061            }
062        }
063        return 0;
064    }
065
066}