source: stable/HeuristicLab.ExtLibs/HeuristicLab.AvalonEdit/5.0.1/AvalonEdit-5.0.1/Rendering/LayerPosition.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 System.Windows;

namespace ICSharpCode.AvalonEdit.Rendering
{
  /// <summary>
  /// An enumeration of well-known layers.
  /// </summary>
  public enum KnownLayer
  {
    /// <summary>
    /// This layer is in the background.
    /// There is no UIElement to represent this layer, it is directly drawn in the TextView.
    /// It is not possible to replace the background layer or insert new layers below it.
    /// </summary>
    /// <remarks>This layer is below the Selection layer.</remarks>
    Background,
    /// <summary>
    /// This layer contains the selection rectangle.
    /// </summary>
    /// <remarks>This layer is between the Background and the Text layers.</remarks>
    Selection,
    /// <summary>
    /// This layer contains the text and inline UI elements.
    /// </summary>
    /// <remarks>This layer is between the Selection and the Caret layers.</remarks>
    Text,
    /// <summary>
    /// This layer contains the blinking caret.
    /// </summary>
    /// <remarks>This layer is above the Text layer.</remarks>
    Caret
  }
  
  /// <summary>
  /// Specifies where a new layer is inserted, in relation to an old layer.
  /// </summary>
  public enum LayerInsertionPosition
  {
    /// <summary>
    /// The new layer is inserted below the specified layer.
    /// </summary>
    Below,
    /// <summary>
    /// The new layer replaces the specified layer. The old layer is removed
    /// from the <see cref="TextView.Layers"/> collection.
    /// </summary>
    Replace,
    /// <summary>
    /// The new layer is inserted above the specified layer.
    /// </summary>
    Above
  }
  
  sealed class LayerPosition : IComparable<LayerPosition>
  {
    internal static readonly DependencyProperty LayerPositionProperty =
      DependencyProperty.RegisterAttached("LayerPosition", typeof(LayerPosition), typeof(LayerPosition));
    
    public static void SetLayerPosition(UIElement layer, LayerPosition value)
    {
      layer.SetValue(LayerPositionProperty, value);
    }
    
    public static LayerPosition GetLayerPosition(UIElement layer)
    {
      return (LayerPosition)layer.GetValue(LayerPositionProperty);
    }
    
    internal readonly KnownLayer KnownLayer;
    internal readonly LayerInsertionPosition Position;
    
    public LayerPosition(KnownLayer knownLayer, LayerInsertionPosition position)
    {
      this.KnownLayer = knownLayer;
      this.Position = position;
    }
    
    public int CompareTo(LayerPosition other)
    {
      int r = this.KnownLayer.CompareTo(other.KnownLayer);
      if (r != 0)
        return r;
      else
        return this.Position.CompareTo(other.Position);
    }
  }
}