/* * Copyright 2008 Google Inc. * * Licensed under the Apache License, Version 2.0 (the "License"); you may not * use this file except in compliance with the License. You may obtain a copy of * the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the * License for the specific language governing permissions and limitations under * the License. */ package com.google.gwt.uibinder.rebind; import java.util.ArrayList; import java.util.HashMap; import java.util.List; import java.util.Map; /** * Methods to dispense unique text tokens to be stitched into text, and to help * replace the tokens with arbitrary content. Multiple tokenators can be used * across the same body of text without fear of the tokens they vend colliding * with each other. * <p> * A arbitrary metadata object ("info") can be associated with each token. */ public class Tokenator { /** * Resolves a token to its literal value. */ public interface Resolver { String resolveToken(String token); } /** * Return values for {@link Tokenator#getOrderedValues(String)}. */ public static class ValueAndInfo { public final String value; public final Object info; private ValueAndInfo(String value, Object info) { this.value = value; this.info = info; } } private static final String TOKEN = "--token--"; private static final String TOKEN_REGEXP = "\\-\\-token\\-\\-"; private static int curId = 0; public static String detokenate(String betokened, Resolver resolver) { StringBuilder detokenated = new StringBuilder(); int index = 0, nextToken = 0; while ((nextToken = betokened.indexOf(TOKEN, index)) > -1) { detokenated.append(betokened.substring(index, nextToken)); int endToken = betokened.indexOf(TOKEN, nextToken + TOKEN.length()); String token = betokened.substring(nextToken, endToken + TOKEN.length()); detokenated.append(resolver.resolveToken(token)); index = endToken + TOKEN.length(); } detokenated.append(betokened.substring(index)); return detokenated.toString(); } public static boolean hasToken(String s) { return s.matches(".*" + TOKEN_REGEXP + "\\d+" + TOKEN_REGEXP + ".*"); } private static String nextToken() { return TOKEN + (curId++) + TOKEN; } private final Map<String, Object> infoMap = new HashMap<String, Object>(); private Map<String, String> tokenToResolved = new HashMap<String, String>(); /** * Given a string filled with tokens created by * {@link #nextToken(Object, String)}, returns it with the tokens replaced by * the original strings. */ public String detokenate(String betokened) { return detokenate(betokened, new Resolver() { public String resolveToken(String token) { return tokenToResolved.get(token); } }); } /** * Returns a list of the values represented by tokens in the given string, and * the info objects corresponding to them. */ public List<ValueAndInfo> getOrderedValues(String betokened) { return getOrderedValues(betokened, new Resolver() { public String resolveToken(String token) { return tokenToResolved.get(token); } }); } /** * Returns a token that can be used to replace the given String, to be * restored by a later call to {@link #detokenate(String)}. Associates * the token with the given info object. * * @param info An arbitrary object to associate with this token. Mmm, metadata * @param resolved The value to replace this token with in later calls to * {@link #detokenate(String)} * @return the token */ public String nextToken(Object info, final String resolved) { String token = nextToken(); tokenToResolved.put(token, resolved); infoMap.put(token, info); return token; } /** * Like {@link #nextToken(String)} with no info. */ public String nextToken(String resolved) { return nextToken(null, resolved); } private List<ValueAndInfo> getOrderedValues(String betokened, Resolver resolver) { List<ValueAndInfo> values = new ArrayList<ValueAndInfo>(); int index = 0, nextToken = 0; while ((nextToken = betokened.indexOf(TOKEN, index)) > -1) { int endToken = betokened.indexOf(TOKEN, nextToken + TOKEN.length()); String token = betokened.substring(nextToken, endToken + TOKEN.length()); values.add(new ValueAndInfo(resolver.resolveToken(token), infoMap.get(token))); index = endToken + TOKEN.length(); } return values; } }