groovy-core/src/main/org/codehaus/groovy/runtime/ClassExtender.java

/*
 * Copyright 2003-2007 the original author or authors.
 *
 * 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 org.codehaus.groovy.runtime;

import groovy.lang.Closure;

import java.util.HashMap;
import java.util.Map;


/**
 * A helper class used by the runtime to allow Groovy classes to be extended at runtime
 * 
 * @author <a href="mailto:james@coredevelopers.net">James Strachan</a>
 * @version $Revision$
 */
public class ClassExtender {
    private Map variables;
    private Map methods;

    public synchronized Object get(String name) {
        if (variables != null) {
            return variables.get(name);
        }
        return null;
    }

    public synchronized void set(String name, Object value) {
        if (variables == null) {
            variables = createMap();
        }
        variables.put(name, value);
    }

    public synchronized void remove(String name) {
        if (variables != null) {
            variables.remove(name);
        }
    }

    public void call(String name, Object params) {
        Closure closure = null;
        synchronized (this) {
            if (methods != null) {
                closure = (Closure) methods.get(name);
            }
        }
        if (closure != null) {
            closure.call(params);
        }
        /*
        else {
            throw DoesNotUnderstandException();
        }
        */
    }

    public synchronized void addMethod(String name, Closure closure) {
        if (methods == null) {
            methods = createMap();
        }
        methods.put(name, methods);
    }

    public synchronized void removeMethod(String name) {
        if (methods != null) {
            methods.remove(name);
        }
    }

    protected Map createMap() {
        return new HashMap();
    }
}