revision.java

Wicket一个开发Java Web应用程序框架。它使得开发web应用程序变得容易而轻松。 Wicket利用一个POJO data beans组件使得它可以与任何持久层技术相结合。

/*
 * ====================================================================
 *
 * 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 [e-mail].
 *
 * 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.ArrayList;
import java.util.Arrays;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;
import java.util.ListIterator;

/**
 * A Revision holds the series of deltas that describe the differences between two sequences.
 * 
 * @version $Revision: 1.1 $ $Date: 2006/03/12 00:24:21 $
 * 
 * @author <a href="mailto:[e-mail]">Juanco Anez</a>
 * @author <a href="mailto:[e-mail]">Brian McBride</a>
 * 
 * @see Delta
 * @see Diff
 * @see Chunk
 * @see Revision
 * 
 * modifications 27 Apr 2003 bwm
 * 
 * Added visitor pattern Visitor interface and accept() method.
 */

public class Revision extends ToString
{

	List deltas_ = new LinkedList();

	/**
	 * Creates an empty Revision.
	 */
	public Revision()
	{
	}

	/**
	 * Adds a delta to this revision.
	 * 
	 * @param delta
	 *            the {@link Delta Delta} to add.
	 */
	public synchronized void addDelta(Delta delta)
	{
		if (delta == null)
		{
			throw new IllegalArgumentException("new delta is null");
		}
		deltas_.add(delta);
	}

	/**
	 * Adds a delta to the start of this revision.
	 * 
	 * @param delta
	 *            the {@link Delta Delta} to add.
	 */
	public synchronized void insertDelta(Delta delta)
	{
		if (delta == null)
		{
			throw new IllegalArgumentException("new delta is null");
		}
		deltas_.add(0, delta);
	}

	/**
	 * Retrieves a delta from this revision by position.
	 * 
	 * @param i
	 *            the position of the delta to retrieve.
	 * @return the specified delta
	 */
	public Delta getDelta(int i)
	{
		return (Delta)deltas_.get(i);
	}

	/**
	 * Returns the number of deltas in this revision.
	 * 
	 * @return the number of deltas.
	 */
	public int size()
	{
		return deltas_.size();
	}

	/**
	 * Applies the series of deltas in this revision as patches to the given text.
	 * 
	 * @param src
	 *            the text to patch, which the method doesn't change.
	 * @return the resulting text after the patches have been applied.
	 * @throws PatchFailedException
	 *             if any of the patches cannot be applied.
	 */
	public Object[] patch(Object[] src) throws PatchFailedException
	{
		List target = new ArrayList(Arrays.asList(src));
		applyTo(target);
		return target.toArray();
	}

	/**
	 * Applies the series of deltas in this revision as patches to the given text.
	 * 
	 * @param target
	 *            the text to patch.
	 * @throws PatchFailedException
	 *             if any of the patches cannot be applied.
	 */
	public synchronized void applyTo(List target) throws PatchFailedException
	{
		ListIterator i = deltas_.listIterator(deltas_.size());
		while (i.hasPrevious())
		{
			Delta delta = (Delta)i.previous();
			delta.patch(target);
		}
	}

	/**
	 * Converts this revision into its Unix diff style string representation.
	 * 
	 * @param s
	 *            a {@link StringBuffer StringBuffer} to which the string representation will be
	 *            appended.
	 */
	public synchronized void toString(StringBuffer s)
	{
		Iterator i = deltas_.iterator();
		while (i.hasNext())
		{
			((Delta)i.next()).toString(s);
		}
	}

	/**
	 * Converts this revision into its RCS style string representation.
	 * 
	 * @param s
	 *            a {@link StringBuffer StringBuffer} to which the string representation will be
	 *            appended.
	 * @param EOL
	 *            the string to use as line separator.
	 */
	public synchronized void toRCSString(StringBuffer s, String EOL)
	{
		Iterator i = deltas_.iterator();
		while (i.hasNext())
		{
			((Delta)i.next()).toRCSString(s, EOL);
		}
	}

	/**
	 * Converts this revision into its RCS style string representation.
	 * 
	 * @param s
	 *            a {@link StringBuffer StringBuffer} to which the string representation will be
	 *            appended.
	 */
	public void toRCSString(StringBuffer s)
	{
		toRCSString(s, Diff.NL);
	}

	/**
	 * Converts this delta into its RCS style string representation.
	 * 
	 * @param EOL
	 *            the string to use as line separator.
	 * @return String
	 */
	public String toRCSString(String EOL)
	{
		StringBuffer s = new StringBuffer();
		toRCSString(s, EOL);
		return s.toString();
	}

	/**
	 * Converts this delta into its RCS style string representation using the default line
	 * separator.
	 * 
	 * @return String
	 */
	public String toRCSString()
	{
		return toRCSString(Diff.NL);
	}

	/**
	 * Accepts a visitor.
	 * 
	 * @param visitor
	 *            the {@link RevisionVisitor} visiting this instance
	 */
	public void accept(RevisionVisitor visitor)
	{
		visitor.visit(this);
		Iterator iter = deltas_.iterator();
		while (iter.hasNext())
		{
			((Delta)iter.next()).accept(visitor);
		}
	}

}