// Copyright (c) AlphaSierraPapa for the SharpDevelop Team (for details please see \doc\copyright.txt)
// This code is distributed under the GNU LGPL (for details please see \doc\license.txt)
using System;
using System.Diagnostics;
namespace ICSharpCode.AvalonEdit.Document
{
/// <summary>
/// Describes a change to a TextDocument.
/// </summary>
sealed class DocumentChangeOperation : IUndoableOperationWithContext
{
TextDocument document;
DocumentChangeEventArgs change;
public DocumentChangeOperation(TextDocument document, DocumentChangeEventArgs change)
{
this.document = document;
this.change = change;
}
public void Undo(UndoStack stack)
{
Debug.Assert(stack.state == UndoStack.StatePlayback);
stack.RegisterAffectedDocument(document);
stack.state = UndoStack.StatePlaybackModifyDocument;
this.Undo();
stack.state = UndoStack.StatePlayback;
}
public void Redo(UndoStack stack)
{
Debug.Assert(stack.state == UndoStack.StatePlayback);
stack.RegisterAffectedDocument(document);
stack.state = UndoStack.StatePlaybackModifyDocument;
this.Redo();
stack.state = UndoStack.StatePlayback;
}
public void Undo()
{
OffsetChangeMap map = change.OffsetChangeMapOrNull;
document.Replace(change.Offset, change.InsertionLength, change.RemovedText, map != null ? map.Invert() : null);
}
public void Redo()
{
document.Replace(change.Offset, change.RemovalLength, change.InsertedText, change.OffsetChangeMapOrNull);
}
}
}