com.google.gwt.core.ext.Generator.java Source code

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Here is the source code for com.google.gwt.core.ext.Generator.java

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/*
 * Copyright 2006 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.core.ext;

/**
 * Generates source code for subclasses during deferred binding requests.
 * Subclasses must be thread-safe.
 */
public abstract class Generator {

    /**
     * Escapes string content to be a valid string literal.
     * 
     * @return an escaped version of <code>unescaped</code>, suitable for being
     *         enclosed in double quotes in Java source
     */
    public static String escape(String unescaped) {
        int extra = 0;
        for (int in = 0, n = unescaped.length(); in < n; ++in) {
            switch (unescaped.charAt(in)) {
            case '\0':
            case '\n':
            case '\r':
            case '\"':
            case '\\':
                ++extra;
                break;
            }
        }

        if (extra == 0) {
            return unescaped;
        }

        char[] oldChars = unescaped.toCharArray();
        char[] newChars = new char[oldChars.length + extra];
        for (int in = 0, out = 0, n = oldChars.length; in < n; ++in, ++out) {
            char c = oldChars[in];
            switch (c) {
            case '\0':
                newChars[out++] = '\\';
                c = '0';
                break;
            case '\n':
                newChars[out++] = '\\';
                c = 'n';
                break;
            case '\r':
                newChars[out++] = '\\';
                c = 'r';
                break;
            case '\"':
                newChars[out++] = '\\';
                c = '"';
                break;
            case '\\':
                newChars[out++] = '\\';
                c = '\\';
                break;
            }
            newChars[out] = c;
        }

        return String.valueOf(newChars);
    }

    /**
     * Generate a default constructible subclass of the requested type. The
     * generator throws <code>UnableToCompleteException</code> if for any reason
     * it cannot provide a substitute class
     * 
     * @return the name of a subclass to substitute for the requested class, or
     *         return <code>null</code> to cause the requested type itself to be
     *         used
     * 
     */
    public abstract String generate(TreeLogger logger, GeneratorContext context, String typeName)
            throws UnableToCompleteException;
}