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    
015    package org.apache.tapestry5.plastic;
016    
017    /**
018     * The end result of a class transformation is a ClassInstantiator that can be used to
019     * instantiate an instance of the transformed class.
020     */
021    public interface ClassInstantiator<T>
022    {
023        /**
024         * Creates and returns a new instance of the transformed class.
025         */
026        T newInstance();
027    
028        /**
029         * Returns a <em>new</em> instantiator that adds the indicated value to the
030         * instance's {@link InstanceContext}.
031         * 
032         * @param valueType
033         *            defines the type of value, and acts as a key to retrieve the value
034         * @param instanceContextValue
035         *            the non-null value stored
036         * @throws AssertionError
037         *             if instanceContextValue is null
038         * @throws IllegalStateException
039         *             if a value of the given value type has already been stored
040         */
041        <V> ClassInstantiator<T> with(Class<V> valueType, V instanceContextValue);
042    }