source: trunk/HeuristicLab.ExtLibs/HeuristicLab.AvalonEdit/5.0.1/AvalonEdit-5.0.1/Utils/TextFormatterFactory.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.Globalization;
using System.Reflection;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Media;
using System.Windows.Media.TextFormatting;

namespace ICSharpCode.AvalonEdit.Utils
{
  /// <summary>
  /// Creates TextFormatter instances that with the correct TextFormattingMode, if running on .NET 4.0.
  /// </summary>
  static class TextFormatterFactory
  {
    #if !DOTNET4
    readonly static DependencyProperty TextFormattingModeProperty;
    
    static TextFormatterFactory()
    {
      Assembly presentationFramework = typeof(FrameworkElement).Assembly;
      Type textOptionsType = presentationFramework.GetType("System.Windows.Media.TextOptions", false);
      if (textOptionsType != null) {
        TextFormattingModeProperty = textOptionsType.GetField("TextFormattingModeProperty").GetValue(null) as DependencyProperty;
      }
    }
    #endif
    
    /// <summary>
    /// Creates a <see cref="TextFormatter"/> using the formatting mode used by the specified owner object.
    /// </summary>
    public static TextFormatter Create(DependencyObject owner)
    {
      if (owner == null)
        throw new ArgumentNullException("owner");
      #if DOTNET4
      return TextFormatter.Create(TextOptions.GetTextFormattingMode(owner));
      #else
      if (TextFormattingModeProperty != null) {
        object formattingMode = owner.GetValue(TextFormattingModeProperty);
        return (TextFormatter)typeof(TextFormatter).InvokeMember(
          "Create",
          BindingFlags.InvokeMethod | BindingFlags.Public | BindingFlags.Static,
          null, null,
          new object[] { formattingMode },
          CultureInfo.InvariantCulture);
      } else {
        return TextFormatter.Create();
      }
      #endif
    }
    
    /// <summary>
    /// Returns whether the specified dependency property affects the text formatter creation.
    /// Controls should re-create their text formatter for such property changes.
    /// </summary>
    public static bool PropertyChangeAffectsTextFormatter(DependencyProperty dp)
    {
      #if DOTNET4
      return dp == TextOptions.TextFormattingModeProperty;
      #else
      return dp == TextFormattingModeProperty && TextFormattingModeProperty != null;
      #endif
    }
    
    /// <summary>
    /// Creates formatted text.
    /// </summary>
    /// <param name="element">The owner element. The text formatter setting are read from this element.</param>
    /// <param name="text">The text.</param>
    /// <param name="typeface">The typeface to use. If this parameter is null, the typeface of the <paramref name="element"/> will be used.</param>
    /// <param name="emSize">The font size. If this parameter is null, the font size of the <paramref name="element"/> will be used.</param>
    /// <param name="foreground">The foreground color. If this parameter is null, the foreground of the <paramref name="element"/> will be used.</param>
    /// <returns>A FormattedText object using the specified settings.</returns>
    public static FormattedText CreateFormattedText(FrameworkElement element, string text, Typeface typeface, double? emSize, Brush foreground)
    {
      if (element == null)
        throw new ArgumentNullException("element");
      if (text == null)
        throw new ArgumentNullException("text");
      if (typeface == null)
        typeface = element.CreateTypeface();
      if (emSize == null)
        emSize = TextBlock.GetFontSize(element);
      if (foreground == null)
        foreground = TextBlock.GetForeground(element);
      #if DOTNET4
      return new FormattedText(
        text,
        CultureInfo.CurrentCulture,
        FlowDirection.LeftToRight,
        typeface,
        emSize.Value,
        foreground,
        null,
        TextOptions.GetTextFormattingMode(element)
      );
      #else
      if (TextFormattingModeProperty != null) {
        object formattingMode = element.GetValue(TextFormattingModeProperty);
        return (FormattedText)Activator.CreateInstance(
          typeof(FormattedText),
          text,
          CultureInfo.CurrentCulture,
          FlowDirection.LeftToRight,
          typeface,
          emSize,
          foreground,
          null,
          formattingMode
        );
      } else {
        return new FormattedText(
          text,
          CultureInfo.CurrentCulture,
          FlowDirection.LeftToRight,
          typeface,
          emSize.Value,
          foreground
        );
      }
      #endif
    }
  }
}