source: trunk/HeuristicLab.ExtLibs/HeuristicLab.AvalonEdit/5.0.1/AvalonEdit-5.0.1/Document/DocumentChangeEventArgs.cs

// 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
// without restriction, including without limitation the rights to use, copy, modify, merge,
// 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
// FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
// DEALINGS IN THE SOFTWARE.

using System;
using ICSharpCode.AvalonEdit.Document;
using ICSharpCode.NRefactory.Editor;

namespace ICSharpCode.AvalonEdit.Document
{
  /// <summary>
  /// Describes a change of the document text.
  /// This class is thread-safe.
  /// </summary>
  [Serializable]
  public class DocumentChangeEventArgs : TextChangeEventArgs
  {
    volatile OffsetChangeMap offsetChangeMap;
    
    /// <summary>
    /// Gets the OffsetChangeMap associated with this document change.
    /// </summary>
    /// <remarks>The OffsetChangeMap instance is guaranteed to be frozen and thus thread-safe.</remarks>
    public OffsetChangeMap OffsetChangeMap {
      get {
        OffsetChangeMap map = offsetChangeMap;
        if (map == null) {
          // create OffsetChangeMap on demand
          map = OffsetChangeMap.FromSingleElement(CreateSingleChangeMapEntry());
          offsetChangeMap = map;
        }
        return map;
      }
    }
    
    internal OffsetChangeMapEntry CreateSingleChangeMapEntry()
    {
      return new OffsetChangeMapEntry(this.Offset, this.RemovalLength, this.InsertionLength);
    }
    
    /// <summary>
    /// Gets the OffsetChangeMap, or null if the default offset map (=single replacement) is being used.
    /// </summary>
    internal OffsetChangeMap OffsetChangeMapOrNull {
      get {
        return offsetChangeMap;
      }
    }
    
    /// <summary>
    /// Gets the new offset where the specified offset moves after this document change.
    /// </summary>
    public override int GetNewOffset(int offset, AnchorMovementType movementType = AnchorMovementType.Default)
    {
      if (offsetChangeMap != null)
        return offsetChangeMap.GetNewOffset(offset, movementType);
      else
        return CreateSingleChangeMapEntry().GetNewOffset(offset, movementType);
    }
    
    /// <summary>
    /// Creates a new DocumentChangeEventArgs object.
    /// </summary>
    public DocumentChangeEventArgs(int offset, string removedText, string insertedText)
      : this(offset, removedText, insertedText, null)
    {
    }
    
    /// <summary>
    /// Creates a new DocumentChangeEventArgs object.
    /// </summary>
    public DocumentChangeEventArgs(int offset, string removedText, string insertedText, OffsetChangeMap offsetChangeMap)
      : base(offset, removedText, insertedText)
    {
      SetOffsetChangeMap(offsetChangeMap);
    }
    
    /// <summary>
    /// Creates a new DocumentChangeEventArgs object.
    /// </summary>
    public DocumentChangeEventArgs(int offset, ITextSource removedText, ITextSource insertedText, OffsetChangeMap offsetChangeMap)
      : base(offset, removedText, insertedText)
    {
      SetOffsetChangeMap(offsetChangeMap);
    }
    
    void SetOffsetChangeMap(OffsetChangeMap offsetChangeMap)
    {
      if (offsetChangeMap != null) {
        if (!offsetChangeMap.IsFrozen)
          throw new ArgumentException("The OffsetChangeMap must be frozen before it can be used in DocumentChangeEventArgs");
        if (!offsetChangeMap.IsValidForDocumentChange(this.Offset, this.RemovalLength, this.InsertionLength))
          throw new ArgumentException("OffsetChangeMap is not valid for this document change", "offsetChangeMap");
        this.offsetChangeMap = offsetChangeMap;
      }
    }
    
    /// <inheritdoc/>
    public override TextChangeEventArgs Invert()
    {
      OffsetChangeMap map = this.OffsetChangeMapOrNull;
      if (map != null) {
        map = map.Invert();
        map.Freeze();
      }
      return new DocumentChangeEventArgs(this.Offset, this.InsertedText, this.RemovedText, map);
    }
  }
}