// $Header: /home/cvs/jakarta-jmeter/src/core/org/apache/jmeter/control/ReplaceableController.java,v 1.4 2004/02/14 03:34:29 sebb Exp $
/*
 * Copyright 2001-2004 The Apache Software Foundation.
 *
 * 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.apache.jmeter.control;

import org.apache.jmeter.testelement.TestElement;
import org.apache.jorphan.collections.HashTree;


/**
 * This interface represents a controller that gets replaced
 * during the compilation phase of test execution in an arbitrary
 * way.
 * 
 * @see org.apache.jmeter.gui.action.AbstractAction
 * 
 * @author  Thad Smith
 * @version $Revision: 1.4 $
 */
public interface ReplaceableController
{
    /**
     * Returns the TestElement that should replace the current 
     * ReplaceableCoroller.
     * 
     * @return TestElement
     * @see org.apache.jmeter.testelement.TestElement
     */
    public TestElement getReplacement();

    /**
     * Used to replace the test execution tree (usually by adding the
     * subelements of the TestElement that is replacing the
     * ReplaceableController.
     * 
     * @param   tree - The current HashTree to be executed.
     * @see org.apache.jorphan.collections.HashTree
     * @see org.apache.jmeter.gui.action.AbstractAction#convertSubTree
     */
    public void replace(HashTree tree);
}