package net.sourceforge.squirrel_sql.client.session.mainpanel;
/*
* Copyright (C) 2004 Gerd Wagner
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library 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.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
import javax.swing.undo.UndoManager;
import javax.swing.undo.UndoableEdit;
import javax.swing.text.AbstractDocument;
import javax.swing.event.DocumentEvent;
/**
* The trick of this UndoManager is to jump over UndoableEdits
* of type DocumentEvent.EventType.CHANGE. These are events like
* coloring that we don't want to see in undo/redo.
*/
public class SquirrelDefaultUndoManager extends UndoManager
{
private static final long serialVersionUID = 1L;
/**
* Default ctor.
*/
public SquirrelDefaultUndoManager()
{
super();
// Prepare to have a lot of DocumentEvent.EventType.CHANGE
setLimit(200000);
}
/**
* The same as super.editToBeUndone() just that we treat DocumentEvent.EventType.CHANGE
* the same way as true == edit.isSignificant().
*/
protected UndoableEdit editToBeUndone()
{
UndoableEdit ue = super.editToBeUndone();
if (ue == null)
{
return null;
}
int i = edits.indexOf(ue);
while (i >= 0)
{
UndoableEdit edit = edits.elementAt(i--);
if (edit.isSignificant())
{
if (edit instanceof AbstractDocument.DefaultDocumentEvent)
{
if (DocumentEvent.EventType.CHANGE != ((AbstractDocument.DefaultDocumentEvent)edit).getType())
{
return edit;
}
}
else
{
return edit;
}
}
}
return null;
}
/**
* The same as super.editToBeUndone() just that we treat DocumentEvent.EventType.CHANGE
* the same way as true == edit.isSignificant().
*
* The method of the super class already seems to be a bit buggy.
* The DocumentEvent.EventType.CHANGE fix doesn't remove the bugs but makes it behave
*/
protected UndoableEdit editToBeRedone()
{
int count = edits.size();
UndoableEdit ue = super.editToBeRedone();
if (null == ue)
{
return null;
}
int i = edits.indexOf(ue);
while (i < count)
{
UndoableEdit edit = edits.elementAt(i++);
if (edit.isSignificant())
{
if (edit instanceof AbstractDocument.DefaultDocumentEvent)
{
if (DocumentEvent.EventType.CHANGE != ((AbstractDocument.DefaultDocumentEvent)edit).getType())
{
return edit;
}
}
else
{
return edit;
}
}
}
return null;
}
}