source: stable/HeuristicLab.ExtLibs/HeuristicLab.AvalonEdit/5.0.1/AvalonEdit-5.0.1/Document/DocumentChangeOperation.cs @ 14113

// Copyright (c) 2014 AlphaSierraPapa for the SharpDevelop Team
// 
// Permission is hereby granted, free of charge, to any person obtaining a copy of this
// software and associated documentation files (the "Software"), to deal in the Software
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// publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons
// to whom the Software is furnished to do so, subject to the following conditions:
// 
// The above copyright notice and this permission notice shall be included in all copies or
// substantial portions of the Software.
// 
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
// INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
// PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE
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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);
    }
  }
}