com.google.gwt.uibinder.rebind.Tokenator Maven / Gradle / Ivy
/*
* 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.
*
* 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 infoMap = new HashMap();
private Map tokenToResolved = new HashMap();
/**
* 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 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 getOrderedValues(String betokened, Resolver resolver) {
List values = new ArrayList();
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;
}
}