| /******************************************************************************* |
| * Copyright (c) 2000, 2003 IBM Corporation and others. |
| * All rights reserved. This program and the accompanying materials |
| * are made available under the terms of the Common Public License v1.0 |
| * which accompanies this distribution, and is available at |
| * http://www.eclipse.org/legal/cpl-v10.html |
| * |
| * Contributors: |
| * IBM Corporation - initial API and implementation |
| *******************************************************************************/ |
| package org.eclipse.text.edits; |
| |
| /** |
| * A visitor for text edits. |
| * <p> |
| * For each different concrete text edit type <it>T</it> there is a method: |
| * <ul> |
| * <li><code>public boolean visit(<it>T</it> node)</code> - Visits the given edit to |
| * perform some arbitrary operation. If <code>true </code> is returned, the given edit's |
| * child edits will be visited next; however, if <code>false</code> is returned, the |
| * given edit's child edits will not be visited. The default implementation provided by |
| * this class calls a generic method <code>visitNode(<it>Testedit</it> node)</code>. |
| * Subclasses may reimplement these method as needed.</li> |
| * </ul> |
| * </p> |
| * <p> |
| * In addition, there are methods for visiting text edits in the |
| * abstract, regardless of node type: |
| * <ul> |
| * <li><code>public void preVisit(TextEdit edit)</code> - Visits |
| * the given edit to perform some arbitrary operation. |
| * This method is invoked prior to the appropriate type-specific |
| * <code>visit</code> method. |
| * The default implementation of this method does nothing. |
| * Subclasses may reimplement this method as needed.</li> |
| * |
| * <li><code>public void postVisit(TextEdit edit)</code> - Visits |
| * the given edit to perform some arbitrary operation. |
| * This method is invoked after the appropriate type-specific |
| * <code>endVisit</code> method. |
| * The default implementation of this method does nothing. |
| * Subclasses may reimplement this method as needed.</li> |
| * </ul> |
| * </p> |
| * <p> |
| * For edits with chldren, the child nodes are visited in increasing order. |
| * </p> |
| * |
| * @see TextEdit#accept(TextEditVisitor) |
| * @since 3.0 |
| */ |
| public class TextEditVisitor { |
| |
| /** |
| * Visits the given text edit prior to the type-specific visit. |
| * (before <code>visit</code>). |
| * <p> |
| * The default implementation does nothing. Subclasses may reimplement. |
| * </p> |
| * |
| * @param edit the node to visit |
| */ |
| public void preVisit(TextEdit edit) { |
| // default implementation: do nothing |
| } |
| |
| /** |
| * Visits the given text edit following the type-specific visit |
| * (after <code>endVisit</code>). |
| * <p> |
| * The default implementation does nothing. Subclasses may reimplement. |
| * </p> |
| * |
| * @param edit the node to visit |
| */ |
| public void postVisit(TextEdit edit) { |
| // default implementation: do nothing |
| } |
| |
| /** |
| * Visits the given text edit. This method is called by default from |
| * type-specific visits. It is not called by a edit's accept method. |
| * The default implementation returns <code>true</code>. |
| * |
| * @param edit the node to visit |
| * @return If <code>true</code> is returned, the given node's child |
| * nodes will be visited next; however, if <code>false</code> is |
| * returned, the given node's child nodes will not be visited. |
| */ |
| public boolean visitNode(TextEdit edit) { |
| return true; |
| } |
| |
| /** |
| * Visits a <code>CopySourceEdit</code> instance. |
| * |
| * @param edit the node to visit |
| * @return If <code>true</code> is returned, the given node's child |
| * nodes will be visited next; however, if <code>false</code> is |
| * returned, the given node's child nodes will not be visited. |
| */ |
| public boolean visit(CopySourceEdit edit) { |
| return visitNode(edit); |
| } |
| |
| /** |
| * Visits a <code>CopyTargetEdit</code> instance. |
| * |
| * @param edit the node to visit |
| * @return If <code>true</code> is returned, the given node's child |
| * nodes will be visited next; however, if <code>false</code> is |
| * returned, the given node's child nodes will not be visited. |
| */ |
| public boolean visit(CopyTargetEdit edit) { |
| return visitNode(edit); |
| } |
| |
| /** |
| * Visits a <code>MoveSourceEdit</code> instance. |
| * |
| * @param edit the node to visit |
| * @return If <code>true</code> is returned, the given node's child |
| * nodes will be visited next; however, if <code>false</code> is |
| * returned, the given node's child nodes will not be visited. |
| */ |
| public boolean visit(MoveSourceEdit edit) { |
| return visitNode(edit); |
| } |
| |
| /** |
| * Visits a <code>MoveTargetEdit</code> instance. |
| * |
| * @param edit the node to visit |
| * @return If <code>true</code> is returned, the given node's child |
| * nodes will be visited next; however, if <code>false</code> is |
| * returned, the given node's child nodes will not be visited. |
| */ |
| public boolean visit(MoveTargetEdit edit) { |
| return visitNode(edit); |
| } |
| |
| /** |
| * Visits a <code>RangeMarker</code> instance. |
| * |
| * @param edit the node to visit |
| * @return If <code>true</code> is returned, the given node's child |
| * nodes will be visited next; however, if <code>false</code> is |
| * returned, the given node's child nodes will not be visited. |
| */ |
| public boolean visit(RangeMarker edit) { |
| return visitNode(edit); |
| } |
| |
| /** |
| * Visits a <code>CopyingRangeMarker</code> instance. |
| * |
| * @param edit the node to visit |
| * @return If <code>true</code> is returned, the given node's child |
| * nodes will be visited next; however, if <code>false</code> is |
| * returned, the given node's child nodes will not be visited. |
| */ |
| public boolean visit(CopyingRangeMarker edit) { |
| return visitNode(edit); |
| } |
| |
| /** |
| * Visits a <code>DeleteEdit</code> instance. |
| * |
| * @param edit the node to visit |
| * @return If <code>true</code> is returned, the given node's child |
| * nodes will be visited next; however, if <code>false</code> is |
| * returned, the given node's child nodes will not be visited. |
| */ |
| public boolean visit(DeleteEdit edit) { |
| return visitNode(edit); |
| } |
| |
| /** |
| * Visits a <code>InsertEdit</code> instance. |
| * |
| * @param edit the node to visit |
| * @return If <code>true</code> is returned, the given node's child |
| * nodes will be visited next; however, if <code>false</code> is |
| * returned, the given node's child nodes will not be visited. |
| */ |
| public boolean visit(InsertEdit edit) { |
| return visitNode(edit); |
| } |
| |
| /** |
| * Visits a <code>ReplaceEdit</code> instance. |
| * |
| * @param edit the node to visit |
| * @return If <code>true</code> is returned, the given node's child |
| * nodes will be visited next; however, if <code>false</code> is |
| * returned, the given node's child nodes will not be visited. |
| */ |
| public boolean visit(ReplaceEdit edit) { |
| return visitNode(edit); |
| } |
| |
| /** |
| * Visits a <code>UndoEdit</code> instance. |
| * |
| * @param edit the node to visit |
| * @return If <code>true</code> is returned, the given node's child |
| * nodes will be visited next; however, if <code>false</code> is |
| * returned, the given node's child nodes will not be visited. |
| */ |
| public boolean visit(UndoEdit edit) { |
| return visitNode(edit); |
| } |
| |
| /** |
| * Visits a <code>MultiTextEdit</code> instance. |
| * |
| * @param edit the node to visit |
| * @return If <code>true</code> is returned, the given node's child |
| * nodes will be visited next; however, if <code>false</code> is |
| * returned, the given node's child nodes will not be visited. |
| */ |
| public boolean visit(MultiTextEdit edit) { |
| return visitNode(edit); |
| } |
| } |