source: branches/3107_LearningALPS/HeuristicLab.ExtLibs/HeuristicLab.AvalonEdit/5.0.1/AvalonEdit-5.0.1/Editing/NoReadOnlySections.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
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using System;
using System.Collections.Generic;
using System.Linq;
using ICSharpCode.AvalonEdit.Document;
using ICSharpCode.NRefactory.Editor;
using ICSharpCode.AvalonEdit.Utils;

namespace ICSharpCode.AvalonEdit.Editing
{
  /// <summary>
  /// <see cref="IReadOnlySectionProvider"/> that has no read-only sections; all text is editable.
  /// </summary>
  sealed class NoReadOnlySections : IReadOnlySectionProvider
  {
    public static readonly NoReadOnlySections Instance = new NoReadOnlySections();
    
    public bool CanInsert(int offset)
    {
      return true;
    }
    
    public IEnumerable<ISegment> GetDeletableSegments(ISegment segment)
    {
      if (segment == null)
        throw new ArgumentNullException("segment");
      // the segment is always deletable
      return ExtensionMethods.Sequence(segment);
    }
  }
  
  /// <summary>
  /// <see cref="IReadOnlySectionProvider"/> that completely disables editing.
  /// </summary>
  sealed class ReadOnlySectionDocument : IReadOnlySectionProvider
  {
    public static readonly ReadOnlySectionDocument Instance = new ReadOnlySectionDocument();
    
    public bool CanInsert(int offset)
    {
      return false;
    }
    
    public IEnumerable<ISegment> GetDeletableSegments(ISegment segment)
    {
      return Enumerable.Empty<ISegment>();
    }
  }
}