/*

 * Copyright (C) 2007-2010 Júlio Vilmar Gesser.

 * Copyright (C) 2011, 2013-2021 The JavaParser Team.

 *

 * This file is part of JavaParser.

 *

 * JavaParser can be used either under the terms of

 * a) the GNU Lesser General Public License as published by

 *     the Free Software Foundation, either version 3 of the License, or

 *     (at your option) any later version.

 * b) the terms of the Apache License

 *

 * You should have received a copy of both licenses in LICENCE.LGPL and

 * LICENCE.APACHE. Please refer to those files for details.

 *

 * JavaParser is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU Lesser General Public License for more details.

 */

package com.github.javaparser.ast.observer;

import com.github.javaparser.ast.Node;

import com.github.javaparser.ast.NodeList;

/**

 * An Observer for an AST element (either a Node or a NodeList).

 */

public interface AstObserver {

    /**

     * Type of change occurring on a List

     */

    enum ListChangeType {

        ADDITION,

        REMOVAL

    }

    /**

     * The value of a property is changed

     *

     * @param observedNode owner of the property

     * @param property property changed

     * @param oldValue value of the property before the change

     * @param newValue value of the property after the change

     */

    void propertyChange(Node observedNode, ObservableProperty property, Object oldValue, Object newValue);

    /**

     * The parent of a node is changed

     *

     * @param observedNode node of which the parent is changed

     * @param previousParent previous parent

     * @param newParent new parent

     */

    void parentChange(Node observedNode, Node previousParent, Node newParent);

    /**

     * A list is changed

     *

     * @param observedNode list changed

     * @param type type of change

     * @param index position at which the changed occurred

     * @param nodeAddedOrRemoved element added or removed

     */

    void listChange(NodeList<?> observedNode, ListChangeType type, int index, Node nodeAddedOrRemoved);

    void listReplacement(NodeList<?> observedNode, int index, Node oldNode, Node newNode);

}