source: branches/3107_LearningALPS/HeuristicLab.ExtLibs/HeuristicLab.AvalonEdit/5.0.1/AvalonEdit-5.0.1/Snippets/SnippetAnchorElement.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
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using System;
using ICSharpCode.AvalonEdit.Document;
using ICSharpCode.NRefactory.Editor;

namespace ICSharpCode.AvalonEdit.Snippets
{
  /// <summary>
  /// Creates a named anchor that can be accessed by other SnippetElements.
  /// </summary>
  public sealed class SnippetAnchorElement : SnippetElement
  {
    /// <summary>
    /// Gets or sets the name of the anchor.
    /// </summary>
    public string Name { get; private set; }
    
    /// <summary>
    /// Creates a SnippetAnchorElement with the supplied name.
    /// </summary>
    public SnippetAnchorElement(string name)
    {
      this.Name = name;
    }
    
    /// <inheritdoc />
    public override void Insert(InsertionContext context)
    {
      TextAnchor start = context.Document.CreateAnchor(context.InsertionPosition);
      start.MovementType = AnchorMovementType.BeforeInsertion;
      start.SurviveDeletion = true;
      AnchorSegment segment = new AnchorSegment(start, start);
      context.RegisterActiveElement(this, new AnchorElement(segment, Name, context));
    }
  }
  
  /// <summary>
  /// AnchorElement created by SnippetAnchorElement.
  /// </summary>
  public sealed class AnchorElement : IActiveElement
  {
    /// <inheritdoc />
    public bool IsEditable {
      get { return false; }
    }
    
    AnchorSegment segment;
    InsertionContext context;
    
    /// <inheritdoc />
    public ISegment Segment {
      get { return segment; }
    }
    
    /// <summary>
    /// Creates a new AnchorElement.
    /// </summary>
    public AnchorElement(AnchorSegment segment, string name, InsertionContext context)
    {
      this.segment = segment;
      this.context = context;
      this.Name = name;
    }
    
    /// <summary>
    /// Gets or sets the text at the anchor.
    /// </summary>
    public string Text {
      get { return context.Document.GetText(segment); }
      set {
        int offset = segment.Offset;
        int length = segment.Length;
        context.Document.Replace(offset, length, value);
        if (length == 0) {
          // replacing an empty anchor segment with text won't enlarge it, so we have to recreate it
          segment = new AnchorSegment(context.Document, offset, value.Length);
        }
      }
    }
    
    /// <summary>
    /// Gets or sets the name of the anchor.
    /// </summary>
    public string Name { get; private set; }
    
    /// <inheritdoc />
    public void OnInsertionCompleted()
    {
    }
    
    /// <inheritdoc />
    public void Deactivate(SnippetEventArgs e)
    {
    }
  }
}