| /* |
| * Copyright (C) 2007-2010 JĂșlio Vilmar Gesser. |
| * Copyright (C) 2011, 2013-2016 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; |
| |
| /** |
| * This AstObserver attach itself to all new nodes added to the nodes already observed. |
| */ |
| public abstract class PropagatingAstObserver implements AstObserver { |
| |
| /** |
| * Wrap a given observer to make it self-propagating. If the given observer is an instance of PropagatingAstObserver |
| * the observer is returned without changes. |
| */ |
| public static PropagatingAstObserver transformInPropagatingObserver(final AstObserver observer) { |
| if (observer instanceof PropagatingAstObserver) { |
| return (PropagatingAstObserver) observer; |
| } |
| return new PropagatingAstObserver() { |
| @Override |
| public void concretePropertyChange(Node observedNode, ObservableProperty property, Object oldValue, Object newValue) { |
| observer.propertyChange(observedNode, property, oldValue, newValue); |
| } |
| |
| @Override |
| public void concreteListChange(NodeList observedNode, ListChangeType type, int index, Node nodeAddedOrRemoved) { |
| observer.listChange(observedNode, type, index, nodeAddedOrRemoved); |
| } |
| |
| @Override |
| public void parentChange(Node observedNode, Node previousParent, Node newParent) { |
| observer.parentChange(observedNode, previousParent, newParent); |
| } |
| }; |
| } |
| |
| @Override |
| public final void propertyChange(Node observedNode, ObservableProperty property, Object oldValue, Object newValue) { |
| considerRemoving(oldValue); |
| considerAdding(newValue); |
| concretePropertyChange(observedNode, property, oldValue, newValue); |
| } |
| |
| @Override |
| public final void listChange(NodeList observedNode, ListChangeType type, int index, Node nodeAddedOrRemoved) { |
| if (type == ListChangeType.REMOVAL) { |
| considerRemoving(nodeAddedOrRemoved); |
| } else if (type == ListChangeType.ADDITION) { |
| considerAdding(nodeAddedOrRemoved); |
| } |
| concreteListChange(observedNode, type, index, nodeAddedOrRemoved); |
| } |
| |
| @Override |
| public void listReplacement(NodeList observedNode, int index, Node oldNode, Node newNode) { |
| if (oldNode == newNode) { |
| return; |
| } |
| considerRemoving(oldNode); |
| considerAdding(newNode); |
| concreteListReplacement(observedNode, index, oldNode, newNode); |
| } |
| |
| public void concretePropertyChange(Node observedNode, ObservableProperty property, Object oldValue, Object newValue) { |
| // do nothing |
| } |
| |
| public void concreteListChange(NodeList observedNode, ListChangeType type, int index, Node nodeAddedOrRemoved) { |
| // do nothing |
| } |
| |
| public void concreteListReplacement(NodeList observedNode, int index, Node oldValue, Node newValue) { |
| // do nothing |
| } |
| |
| @Override |
| public void parentChange(Node observedNode, Node previousParent, Node newParent) { |
| // do nothing |
| } |
| |
| private void considerRemoving(Object element) { |
| if (element instanceof Observable) { |
| if (((Observable) element).isRegistered(this)) { |
| ((Observable) element).unregister(this); |
| } |
| } |
| } |
| |
| private void considerAdding(Object element) { |
| if (element instanceof Node) { |
| ((Node) element).registerForSubtree(this); |
| } else if (element instanceof Observable) { |
| ((Observable) element).register(this); |
| } |
| } |
| |
| } |