mirror of git://gcc.gnu.org/git/gcc.git
				
				
				
			
		
			
				
	
	
		
			570 lines
		
	
	
		
			15 KiB
		
	
	
	
		
			Java
		
	
	
	
			
		
		
	
	
			570 lines
		
	
	
		
			15 KiB
		
	
	
	
		
			Java
		
	
	
	
/* StringContent.java --
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   Copyright (C) 2005, 2006 Free Software Foundation, Inc.
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This file is part of GNU Classpath.
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GNU Classpath is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2, or (at your option)
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any later version.
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GNU Classpath is distributed in the hope that it will be useful, but
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WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with GNU Classpath; see the file COPYING.  If not, write to the
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Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
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02110-1301 USA.
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Linking this library statically or dynamically with other modules is
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making a combined work based on this library.  Thus, the terms and
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conditions of the GNU General Public License cover the whole
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combination.
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As a special exception, the copyright holders of this library give you
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permission to link this library with independent modules to produce an
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executable, regardless of the license terms of these independent
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modules, and to copy and distribute the resulting executable under
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terms of your choice, provided that you also meet, for each linked
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independent module, the terms and conditions of the license of that
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module.  An independent module is a module which is not derived from
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or based on this library.  If you modify this library, you may extend
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this exception to your version of the library, but you are not
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obligated to do so.  If you do not wish to do so, delete this
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exception statement from your version. */
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package javax.swing.text;
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import java.io.Serializable;
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import java.lang.ref.Reference;
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import java.lang.ref.ReferenceQueue;
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import java.lang.ref.WeakReference;
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import java.util.Iterator;
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import java.util.Vector;
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import javax.swing.undo.AbstractUndoableEdit;
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import javax.swing.undo.CannotRedoException;
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import javax.swing.undo.CannotUndoException;
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import javax.swing.undo.UndoableEdit;
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/**
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 * An implementation of the <code>AbstractDocument.Content</code>
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 * interface useful for small documents or debugging. The character
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 * content is a simple character array. It's not really efficient.
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 *
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 * <p>Do not use this class for large size.</p>
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 */
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public final class StringContent
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  implements AbstractDocument.Content, Serializable
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{
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  /**
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   * Stores a reference to a mark that can be resetted to the original value
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   * after a mark has been moved. This is used for undoing actions.
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   */
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  private class UndoPosRef
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  {
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    /**
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     * The mark that might need to be reset.
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     */
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    private Mark mark;
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    /**
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     * The original offset to reset the mark to.
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     */
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    private int undoOffset;
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    /**
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     * Creates a new UndoPosRef.
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     *
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     * @param m the mark
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     */
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    UndoPosRef(Mark m)
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    {
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      mark = m;
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      undoOffset = mark.mark;
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    }
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    /**
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     * Resets the position of the mark to the value that it had when
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     * creating this UndoPosRef.
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     */
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    void reset()
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    {
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      mark.mark = undoOffset;
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    }
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  }
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  /**
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   * Holds a mark into the buffer that is used by StickyPosition to find
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   * the actual offset of the position. This is pulled out of the
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   * GapContentPosition object so that the mark and position can be handled
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   * independently, and most important, so that the StickyPosition can
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   * be garbage collected while we still hold a reference to the Mark object.
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   */
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  private class Mark
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  {
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    /**
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     * The actual mark into the buffer.
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     */
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    int mark;
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    /**
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     * The number of GapContentPosition object that reference this mark. If
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     * it reaches zero, it get's deleted by
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     * {@link StringContent#garbageCollect()}.
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     */
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    int refCount;
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    /**
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     * Creates a new Mark object for the specified offset.
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     *
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     * @param offset the offset
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     */
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    Mark(int offset)
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    {
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      mark = offset;
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    }
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  }
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  /** The serialization UID (compatible with JDK1.5). */
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  private static final long serialVersionUID = 4755994433709540381L;
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  // This is package-private to avoid an accessor method.
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  char[] content;
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  private int count;
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  /**
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   * Holds the marks for the positions.
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   *
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   * This is package private to avoid accessor methods.
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   */
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  Vector marks;
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  private class InsertUndo extends AbstractUndoableEdit
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  {
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    private int start;
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    private int length;
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    private String redoContent;
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    private Vector positions;
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    public InsertUndo(int start, int length)
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    {
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      super();
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      this.start = start;
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      this.length = length;
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    }
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    public void undo()
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    {
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      super.undo();
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      try
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        {
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          if (marks != null)
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            positions = getPositionsInRange(null, start, length);
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          redoContent = getString(start, length);
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          remove(start, length);
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        }
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      catch (BadLocationException b)
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        {
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          throw new CannotUndoException();
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        }
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    }
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    public void redo()
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    {
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      super.redo();
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      try
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        {
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          insertString(start, redoContent);
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          redoContent = null;
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          if (positions != null)
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            {
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              updateUndoPositions(positions);
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              positions = null;
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            }
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        }
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      catch (BadLocationException b)
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        {
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          throw new CannotRedoException();
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        }
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    }
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  }
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  private class RemoveUndo extends AbstractUndoableEdit
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  {
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    private int start;
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    private int len;
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    private String undoString;
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    Vector positions;
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    public RemoveUndo(int start, String str)
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    {
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      super();
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      this.start = start;
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      len = str.length();
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      this.undoString = str;
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      if (marks != null)
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        positions = getPositionsInRange(null, start, str.length());
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    }
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    public void undo()
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    {
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      super.undo();
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      try
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        {
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          StringContent.this.insertString(this.start, this.undoString);
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          if (positions != null)
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            {
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              updateUndoPositions(positions);
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              positions = null;
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            }
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          undoString = null;
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        }
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      catch (BadLocationException bad)
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        {
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          throw new CannotUndoException();
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        }
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    }
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    public void redo()
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    {
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      super.redo();
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      try
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        {
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          undoString = getString(start, len);
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          if (marks != null)
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            positions = getPositionsInRange(null, start, len);
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          remove(this.start, len);
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        }
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      catch (BadLocationException bad)
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        {
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          throw new CannotRedoException();
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        }
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    }
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  }
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  private class StickyPosition implements Position
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  {
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    Mark mark;
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    public StickyPosition(int offset)
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    {
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      // Try to make space.
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      garbageCollect();
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      mark = new Mark(offset);
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      mark.refCount++;
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      marks.add(mark);
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      new WeakReference(this, queueOfDeath);
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    }
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    /**
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     * Should be >=0.
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     */
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    public int getOffset()
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    {
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      return mark.mark;
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    }
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  }
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  /**
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   * Used in {@link #remove(int,int)}.
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   */
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  private static final char[] EMPTY = new char[0];
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  /**
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   * Queues all references to GapContentPositions that are about to be
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   * GC'ed. This is used to remove the corresponding marks from the
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   * positionMarks array if the number of references to that mark reaches zero.
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   *
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   * This is package private to avoid accessor synthetic methods.
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   */
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  ReferenceQueue queueOfDeath;
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  /**
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   * Creates a new instance containing the string "\n".  This is equivalent
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   * to calling {@link #StringContent(int)} with an <code>initialLength</code>
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   * of 10.
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   */
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  public StringContent()
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  {
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    this(10);
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  }
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  /**
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   * Creates a new instance containing the string "\n".
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   *
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   * @param initialLength  the initial length of the underlying character
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   *                       array used to store the content.
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   */
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  public StringContent(int initialLength)
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  {
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    super();
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    queueOfDeath = new ReferenceQueue();
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    if (initialLength < 1)
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      initialLength = 1;
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    this.content = new char[initialLength];
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    this.content[0] = '\n';
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    this.count = 1;
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  }
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  protected Vector getPositionsInRange(Vector v,
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                                       int offset,
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                                       int length)
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  {
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    Vector refPos = v == null ? new Vector() : v;
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    Iterator iter = marks.iterator();
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    while(iter.hasNext())
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      {
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        Mark m = (Mark) iter.next();
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        if (offset <= m.mark && m.mark <= offset + length)
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          refPos.add(new UndoPosRef(m));
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      }
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    return refPos;
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  }
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  /**
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   * Creates a position reference for the character at the given offset.  The
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   * position offset will be automatically updated when new characters are
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   * inserted into or removed from the content.
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   *
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   * @param offset  the character offset.
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   *
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   * @throws BadLocationException if offset is outside the bounds of the
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   *         content.
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   */
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  public Position createPosition(int offset) throws BadLocationException
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  {
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    // Lazily create marks vector.
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    if (marks == null)
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      marks = new Vector();
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    StickyPosition sp = new StickyPosition(offset);
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    return sp;
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  }
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  /**
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   * Returns the length of the string content, including the '\n' character at
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   * the end.
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   *
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   * @return The length of the string content.
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   */
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  public int length()
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  {
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    return count;
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  }
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  /**
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   * Inserts <code>str</code> at the given position and returns an
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   * {@link UndoableEdit} that enables undo/redo support.
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   *
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   * @param where  the insertion point (must be less than
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   *               <code>length()</code>).
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   * @param str  the string to insert (<code>null</code> not permitted).
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   *
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   * @return An object that can undo the insertion.
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   */
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  public UndoableEdit insertString(int where, String str)
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    throws BadLocationException
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  {
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    checkLocation(where, 0);
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    if (where == this.count)
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      throw new BadLocationException("Invalid location", 1);
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    if (str == null)
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      throw new NullPointerException();
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    char[] insert = str.toCharArray();
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    replace(where, 0, insert);
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    // Move all the positions.
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    if (marks != null)
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      {
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        Iterator iter = marks.iterator();
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        int start = where;
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        if (start == 0)
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          start = 1;
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        while (iter.hasNext())
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          {
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            Mark m = (Mark) iter.next();
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            if (m.mark >= start)
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              m.mark += str.length();
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          }
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      }
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    InsertUndo iundo = new InsertUndo(where, insert.length);
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    return iundo;
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  }
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  /**
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   * Removes the specified range of characters and returns an
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   * {@link UndoableEdit} that enables undo/redo support.
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   *
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   * @param where  the starting index.
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   * @param nitems  the number of characters.
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   *
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   * @return An object that can undo the removal.
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   *
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   * @throws BadLocationException if the character range extends outside the
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   *         bounds of the content OR includes the last character.
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   */
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  public UndoableEdit remove(int where, int nitems) throws BadLocationException
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  {
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    checkLocation(where, nitems + 1);
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    RemoveUndo rundo = new RemoveUndo(where, new String(this.content, where,
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        nitems));
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    replace(where, nitems, EMPTY);
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    // Move all the positions.
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    if (marks != null)
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      {
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        Iterator iter = marks.iterator();
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        while (iter.hasNext())
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          {
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            Mark m = (Mark) iter.next();
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            if (m.mark >= where + nitems)
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              m.mark -= nitems;
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            else if (m.mark >= where)
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              m.mark = where;
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          }
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      }
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    return rundo;
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  }
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  private void replace(int offs, int numRemove, char[] insert)
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  {
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    int insertLength = insert.length;
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    int delta = insertLength - numRemove;
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    int src = offs + numRemove;
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    int numMove = count - src;
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    int dest = src + delta;
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    if (count + delta >= content.length)
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      {
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        // Grow data array.
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        int newLength = Math.max(2 * content.length, count + delta);
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        char[] newContent = new char[newLength];
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        System.arraycopy(content, 0, newContent, 0, offs);
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        System.arraycopy(insert, 0, newContent, offs, insertLength);
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        System.arraycopy(content, src, newContent, dest, numMove);
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        content = newContent;
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      }
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    else
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      {
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        System.arraycopy(content, src, content, dest, numMove);
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        System.arraycopy(insert, 0, content, offs, insertLength);
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      }
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    count += delta;
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  }
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  /**
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   * Returns a new <code>String</code> containing the characters in the
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   * specified range.
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   *
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   * @param where  the start index.
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   * @param len  the number of characters.
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   *
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   * @return A string.
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   *
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   * @throws BadLocationException if the requested range of characters extends
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   *         outside the bounds of the content.
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   */
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  public String getString(int where, int len) throws BadLocationException
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  {
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    // The RI throws a StringIndexOutOfBoundsException here, which
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    // smells like a bug. We throw a BadLocationException instead.
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    checkLocation(where, len);
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    return new String(this.content, where, len);
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  }
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  /**
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   * Updates <code>txt</code> to contain a direct reference to the underlying
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   * character array.
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   *
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   * @param where  the index of the first character.
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   * @param len  the number of characters.
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   * @param txt  a carrier for the return result (<code>null</code> not
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   *             permitted).
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   *
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   * @throws BadLocationException if the requested character range is not
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   *                              within the bounds of the content.
 | 
						|
   * @throws NullPointerException if <code>txt</code> is <code>null</code>.
 | 
						|
   */
 | 
						|
  public void getChars(int where, int len, Segment txt)
 | 
						|
    throws BadLocationException
 | 
						|
  {
 | 
						|
    if (where + len > count)
 | 
						|
      throw new BadLocationException("Invalid location", where + len);
 | 
						|
    txt.array = content;
 | 
						|
    txt.offset = where;
 | 
						|
    txt.count = len;
 | 
						|
  }
 | 
						|
 | 
						|
 | 
						|
  /**
 | 
						|
   * Resets the positions in the specified vector to their original offset
 | 
						|
   * after a undo operation is performed. For example, after removing some
 | 
						|
   * content, the positions in the removed range will all be set to one
 | 
						|
   * offset. This method restores the positions to their original offsets
 | 
						|
   * after an undo.
 | 
						|
   */
 | 
						|
  protected void updateUndoPositions(Vector positions)
 | 
						|
  {
 | 
						|
    for (Iterator i = positions.iterator(); i.hasNext();)
 | 
						|
      {
 | 
						|
        UndoPosRef pos = (UndoPosRef) i.next();
 | 
						|
        pos.reset();
 | 
						|
      }
 | 
						|
  }
 | 
						|
 | 
						|
  /**
 | 
						|
   * A utility method that checks the validity of the specified character
 | 
						|
   * range.
 | 
						|
   *
 | 
						|
   * @param where  the first character in the range.
 | 
						|
   * @param len  the number of characters in the range.
 | 
						|
   *
 | 
						|
   * @throws BadLocationException if the specified range is not within the
 | 
						|
   *         bounds of the content.
 | 
						|
   */
 | 
						|
  void checkLocation(int where, int len) throws BadLocationException
 | 
						|
  {
 | 
						|
    if (where < 0)
 | 
						|
      throw new BadLocationException("Invalid location", 1);
 | 
						|
    else if (where > this.count)
 | 
						|
      throw new BadLocationException("Invalid location", this.count);
 | 
						|
    else if ((where + len) > this.count)
 | 
						|
      throw new BadLocationException("Invalid range", this.count);
 | 
						|
  }
 | 
						|
 | 
						|
  /**
 | 
						|
   * Polls the queue of death for GapContentPositions, updates the
 | 
						|
   * corresponding reference count and removes the corresponding mark
 | 
						|
   * if the refcount reaches zero.
 | 
						|
   *
 | 
						|
   * This is package private to avoid accessor synthetic methods.
 | 
						|
   */
 | 
						|
  void garbageCollect()
 | 
						|
  {
 | 
						|
    Reference ref = queueOfDeath.poll();
 | 
						|
    while (ref != null)
 | 
						|
      {
 | 
						|
        if (ref != null)
 | 
						|
          {
 | 
						|
            StickyPosition pos = (StickyPosition) ref.get();
 | 
						|
            Mark m = pos.mark;
 | 
						|
            m.refCount--;
 | 
						|
            if (m.refCount == 0)
 | 
						|
              marks.remove(m);
 | 
						|
          }
 | 
						|
        ref = queueOfDeath.poll();
 | 
						|
      }
 | 
						|
  }
 | 
						|
}
 |