| /* |
| * ==================================================================== |
| * |
| * The Apache Software License, Version 1.1 |
| * |
| * Copyright (c) 1999-2003 The Apache Software Foundation. |
| * All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * |
| * 1. Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * |
| * 2. Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in |
| * the documentation and/or other materials provided with the |
| * distribution. |
| * |
| * 3. The end-user documentation included with the redistribution, if |
| * any, must include the following acknowledgement: |
| * "This product includes software developed by the |
| * Apache Software Foundation (http://www.apache.org/)." |
| * Alternately, this acknowledgement may appear in the software itself, |
| * if and wherever such third-party acknowledgements normally appear. |
| * |
| * 4. The names "The Jakarta Project", "Commons", and "Apache Software |
| * Foundation" must not be used to endorse or promote products derived |
| * from this software without prior written permission. For written |
| * permission, please contact apache@apache.org. |
| * |
| * 5. Products derived from this software may not be called "Apache" |
| * nor may "Apache" appear in their names without prior written |
| * permission of the Apache Software Foundation. |
| * |
| * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED |
| * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
| * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE |
| * DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR |
| * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF |
| * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND |
| * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, |
| * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT |
| * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| * SUCH DAMAGE. |
| * ==================================================================== |
| * |
| * This software consists of voluntary contributions made by many |
| * individuals on behalf of the Apache Software Foundation. For more |
| * information on the Apache Software Foundation, please see |
| * <http://www.apache.org/>. |
| * |
| */ |
| |
| package org.apache.wicket.util.diff; |
| |
| import java.util.List; |
| |
| /** |
| * Holds a "delta" difference between to revisions of a text. |
| * |
| * @version $Revision: 1.1 $ $Date: 2006/03/12 00:24:21 $ |
| * |
| * @author <a href="mailto:juanco@suigeneris.org">Juanco Anez</a> |
| * @author <a href="mailto:bwm@hplb.hpl.hp.com">Brian McBride</a> |
| * @see Diff |
| * @see Chunk |
| * @see Revision modifications |
| * |
| * 27 Apr 2003 bwm |
| * |
| * Added getOriginal() and getRevised() accessor methods Added visitor pattern accept() method |
| */ |
| |
| public abstract class Delta extends ToString |
| { |
| |
| protected Chunk original; |
| |
| protected Chunk revised; |
| |
| static Class<?>[][] DeltaClass; |
| |
| static |
| { |
| DeltaClass = new Class[2][2]; |
| try |
| { |
| DeltaClass[0][0] = ChangeDelta.class; |
| DeltaClass[0][1] = AddDelta.class; |
| DeltaClass[1][0] = DeleteDelta.class; |
| DeltaClass[1][1] = ChangeDelta.class; |
| } |
| catch (Exception ignored) |
| { |
| } |
| } |
| |
| /** |
| * Returns a Delta that corresponds to the given chunks in the original and revised text |
| * respectively. |
| * |
| * @param orig |
| * the chunk in the original text. |
| * @param rev |
| * the chunk in the revised text. |
| * @return Delta |
| */ |
| public static Delta newDelta(final Chunk orig, final Chunk rev) |
| { |
| Class<?> c = DeltaClass[orig.size() > 0 ? 1 : 0][rev.size() > 0 ? 1 : 0]; |
| Delta result; |
| try |
| { |
| result = (Delta)c.getDeclaredConstructor().newInstance(); |
| } |
| catch (Exception e) |
| { |
| return null; |
| } |
| result.init(orig, rev); |
| return result; |
| } |
| |
| /** |
| * Creates an uninitialized delta. |
| */ |
| protected Delta() |
| { |
| } |
| |
| /** |
| * Creates a delta object with the given chunks from the original and revised texts. |
| * |
| * @param orig |
| * @param rev |
| */ |
| protected Delta(final Chunk orig, final Chunk rev) |
| { |
| init(orig, rev); |
| } |
| |
| /** |
| * Initializes the delta with the given chunks from the original and revised texts. |
| * |
| * @param orig |
| * @param rev |
| */ |
| protected void init(final Chunk orig, final Chunk rev) |
| { |
| original = orig; |
| revised = rev; |
| } |
| |
| /** |
| * Verifies that this delta can be used to patch the given text. |
| * |
| * @param target |
| * the text to patch. |
| * @throws PatchFailedException |
| * if the patch cannot be applied. |
| */ |
| public abstract void verify(List<Object> target) throws PatchFailedException; |
| |
| /** |
| * Applies this delta as a patch to the given text. |
| * |
| * @param target |
| * the text to patch. |
| * @throws PatchFailedException |
| * if the patch cannot be applied. |
| */ |
| public final void patch(final List<Object> target) throws PatchFailedException |
| { |
| verify(target); |
| try |
| { |
| applyTo(target); |
| } |
| catch (Exception e) |
| { |
| throw new PatchFailedException(e.getMessage()); |
| } |
| } |
| |
| /** |
| * Applies this delta as a patch to the given text. |
| * |
| * @param target |
| * the text to patch. |
| */ |
| public abstract void applyTo(List<Object> target); |
| |
| /** |
| * Converts this delta into its Unix diff style string representation. |
| * |
| * @param s |
| * a {@link StringBuilder StringBuffer} to which the string representation will be |
| * appended. |
| */ |
| @Override |
| public void toString(final StringBuilder s) |
| { |
| original.rangeString(s); |
| s.append("x"); |
| revised.rangeString(s); |
| s.append(Diff.NL); |
| original.toString(s, "> ", "\n"); |
| s.append("---"); |
| s.append(Diff.NL); |
| revised.toString(s, "< ", "\n"); |
| } |
| |
| /** |
| * Converts this delta into its RCS style string representation. |
| * |
| * @param s |
| * a {@link StringBuilder StringBuffer} to which the string representation will be |
| * appended. |
| * @param EOL |
| * the string to use as line separator. |
| */ |
| public abstract void toRCSString(StringBuilder s, String EOL); |
| |
| /** |
| * Converts this delta into its RCS style string representation. |
| * |
| * @param EOL |
| * the string to use as line separator. |
| * @return String |
| */ |
| public String toRCSString(final String EOL) |
| { |
| StringBuilder s = new StringBuilder(); |
| toRCSString(s, EOL); |
| return s.toString(); |
| } |
| |
| /** |
| * Accessor method to return the chunk representing the original sequence of items |
| * |
| * @return the original sequence |
| */ |
| public Chunk getOriginal() |
| { |
| return original; |
| } |
| |
| /** |
| * Accessor method to return the chunk representing the updated sequence of items. |
| * |
| * @return the updated sequence |
| */ |
| public Chunk getRevised() |
| { |
| return revised; |
| } |
| |
| /** |
| * Accepts a visitor. |
| * <p> |
| * See the Visitor pattern in "Design Patterns" by the GOF4. |
| * |
| * @param visitor |
| * The visitor. |
| */ |
| public abstract void accept(RevisionVisitor visitor); |
| } |