    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}