001// Copyright 2004, 2005 The Apache Software Foundation
002//
003// Licensed under the Apache License, Version 2.0 (the "License");
004// you may not use this file except in compliance with the License.
005// You may obtain a copy of the License at
006//
007//     http://www.apache.org/licenses/LICENSE-2.0
008//
009// Unless required by applicable law or agreed to in writing, software
010// distributed under the License is distributed on an "AS IS" BASIS,
011// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
012// See the License for the specific language governing permissions and
013// limitations under the License.
014
015package org.apache.tapestry.util.text;
016
017import java.util.HashMap;
018import java.util.Map;
019
020/**
021 * The default implementation of a character translator source.
022 * Returns a standard HTML translator that encodes everything that is non-safe
023 * or an HTML translator that encodes only non-safe ASCII symbols 
024 * if the encoding is a unicode one. 
025 * 
026 * @author mb
027 * @since 4.0
028 */
029public class DefaultCharacterTranslatorSource implements ICharacterTranslatorSource
030{
031        private static final ICharacterTranslator DEFAULT_TRANSLATOR = new MarkupCharacterTranslator();
032        private static final ICharacterTranslator UNICODE_TRANSLATOR = new MarkupCharacterTranslator(false);
033
034        private final static Map _translators;
035        
036        static {
037                _translators = new HashMap();
038                _translators.put("UTF-8", UNICODE_TRANSLATOR);
039                _translators.put("UTF-7", UNICODE_TRANSLATOR);
040                _translators.put("UTF-16", UNICODE_TRANSLATOR);
041                _translators.put("UTF-16BE", UNICODE_TRANSLATOR);
042                _translators.put("UTF-16LE", UNICODE_TRANSLATOR);
043        }
044        
045        /**
046         * Returns a translator that encodes all non-safe characters into their HTML equivalents.
047         * 
048         * @see org.apache.tapestry.util.text.ICharacterTranslatorSource#getDefaultTranslator()
049         */
050        public ICharacterTranslator getDefaultTranslator() {
051                return DEFAULT_TRANSLATOR;
052        }
053
054        /**
055         * If the encoding is a Unicode one, returns a translator that encodes only the 
056         * non-safe ASCII characters and leaves the others untouched.
057         * Otherwise, returns the default translator.
058         * 
059         * @see org.apache.tapestry.util.text.ICharacterTranslatorSource#getTranslator(java.lang.String)
060         */
061        public ICharacterTranslator getTranslator(String encoding) {
062                ICharacterTranslator translator = (ICharacterTranslator) _translators.get(encoding.toUpperCase());
063                if (translator != null)
064                        return translator;
065                return getDefaultTranslator();
066        }
067        
068}