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;
023
024/**
025 * Executes a sequence of translators one after the other. Execution ends whenever
026 * the first translator consumes codepoints from the input.
027 *
028 * @since 1.0
029 */
030public class AggregateTranslator extends CharSequenceTranslator {
031
032    /**
033     * Translator list.
034     */
035    private final List<CharSequenceTranslator> translators = new ArrayList<>();
036
037    /**
038     * Specify the translators to be used at creation time.
039     *
040     * @param translators CharSequenceTranslator array to aggregate
041     */
042    public AggregateTranslator(final CharSequenceTranslator... translators) {
043        if (translators != null) {
044            for (final CharSequenceTranslator translator : translators) {
045                if (translator != null) {
046                    this.translators.add(translator);
047                }
048            }
049        }
050    }
051
052    /**
053     * The first translator to consume codepoints from the input is the 'winner'.
054     * Execution stops with the number of consumed codepoints being returned.
055     * {@inheritDoc}
056     */
057    @Override
058    public int translate(final CharSequence input, final int index, final Writer out) throws IOException {
059        for (final CharSequenceTranslator translator : translators) {
060            final int consumed = translator.translate(input, index, out);
061            if (consumed != 0) {
062                return consumed;
063            }
064        }
065        return 0;
066    }
067
068}