/*
 * Copyright 2006 Takahiro Nakamura.
 *
 * 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 woolpack.typeconvert;

import woolpack.fn.Delegator;
import woolpack.fn.Fn;

/**
 * 変換前の値が変換後の型の変数に設定可能でない場合に委譲する関数です。
 * <br/>適用しているデザインパターン：Bolking。
 * 
 * @author nakamura
 * 
 */
public class DelegationIfNecessityConverter extends Delegator<ConvertContext, Void, RuntimeException> {

	/**
	 * 
	 * @param fn 委譲先。
	 */
	public DelegationIfNecessityConverter(
			final Fn<? super ConvertContext, Void, ? extends RuntimeException> fn) {
		super(fn);
	}

	@Override
	public Void exec(final ConvertContext c) {
		if (c.getValue() != null
				&& c.getToType() != null
				&& !((Class<?>) c.getToType()).isAssignableFrom(c.getValue().getClass())) {
			super.exec(c);
		}
		return null;
	}
}
