001// Copyright 2011 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.tapestry5.internal.plastic;
016
017import org.apache.tapestry5.plastic.FieldHandle;
018import org.apache.tapestry5.plastic.MethodHandle;
019import org.apache.tapestry5.plastic.MethodInvocationResult;
020import org.apache.tapestry5.plastic.PlasticClass;
021
022/**
023 * The interface for a "shim" class that provides the necessary hooks needed
024 * by {@link FieldHandle} and {@link MethodHandle} implementations for a particular,
025 * instantiated {@link PlasticClass}.
026 */
027public abstract class PlasticClassHandleShim
028{
029    /**
030     * Gets the field at the given index.
031     * 
032     * @param instance
033     *            object to read instance field from
034     * @param fieldIndex
035     *            assigned index for the field
036     * @return the field's value
037     * @see FieldHandle#get(Object)
038     */
039    public Object get(Object instance, int fieldIndex)
040    {
041        return null;
042    }
043
044    /**
045     * Sets the value of a field.
046     * 
047     * @param instance
048     *            object to update instance field in
049     * @param fieldIndex
050     *            assigned index for the field
051     * @param newValue
052     *            new value for field
053     * @see FieldHandle#set(Object, Object)
054     */
055    public void set(Object instance, int fieldIndex, Object newValue)
056    {
057    }
058
059    /**
060     * Invokes a method.
061     * 
062     * @param instance
063     *            object to invoke a method upon
064     * @param methodIndex
065     *            assigned index for the method
066     * @param arguments
067     *            arguments to pass to the method
068     * @return result of invoking the method
069     */
070    public MethodInvocationResult invoke(Object instance, int methodIndex, Object[] arguments)
071    {
072        return null;
073    }
074}