source: branches/2434_crossvalidation/HeuristicLab.ExtLibs/HeuristicLab.AvalonEdit/5.0.1/AvalonEdit-5.0.1/Utils/ExtensionMethods.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.Collections.Generic;
using System.Diagnostics;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Media;
using System.Xml;

namespace ICSharpCode.AvalonEdit.Utils
{
  static class ExtensionMethods
  {
    #region Epsilon / IsClose / CoerceValue
    /// <summary>
    /// Epsilon used for <c>IsClose()</c> implementations.
    /// We can use up quite a few digits in front of the decimal point (due to visual positions being relative to document origin),
    /// and there's no need to be too accurate (we're dealing with pixels here),
    /// so we will use the value 0.01.
    /// Previosly we used 1e-8 but that was causing issues:
    /// http://community.sharpdevelop.net/forums/t/16048.aspx
    /// </summary>
    public const double Epsilon = 0.01;
    
    /// <summary>
    /// Returns true if the doubles are close (difference smaller than 0.01).
    /// </summary>
    public static bool IsClose(this double d1, double d2)
    {
      if (d1 == d2) // required for infinities
        return true;
      return Math.Abs(d1 - d2) < Epsilon;
    }
    
    /// <summary>
    /// Returns true if the doubles are close (difference smaller than 0.01).
    /// </summary>
    public static bool IsClose(this Size d1, Size d2)
    {
      return IsClose(d1.Width, d2.Width) && IsClose(d1.Height, d2.Height);
    }
    
    /// <summary>
    /// Returns true if the doubles are close (difference smaller than 0.01).
    /// </summary>
    public static bool IsClose(this Vector d1, Vector d2)
    {
      return IsClose(d1.X, d2.X) && IsClose(d1.Y, d2.Y);
    }
    
    /// <summary>
    /// Forces the value to stay between mininum and maximum.
    /// </summary>
    /// <returns>minimum, if value is less than minimum.
    /// Maximum, if value is greater than maximum.
    /// Otherwise, value.</returns>
    public static double CoerceValue(this double value, double minimum, double maximum)
    {
      return Math.Max(Math.Min(value, maximum), minimum);
    }
    
    /// <summary>
    /// Forces the value to stay between mininum and maximum.
    /// </summary>
    /// <returns>minimum, if value is less than minimum.
    /// Maximum, if value is greater than maximum.
    /// Otherwise, value.</returns>
    public static int CoerceValue(this int value, int minimum, int maximum)
    {
      return Math.Max(Math.Min(value, maximum), minimum);
    }
    #endregion
    
    #region CreateTypeface
    /// <summary>
    /// Creates typeface from the framework element.
    /// </summary>
    public static Typeface CreateTypeface(this FrameworkElement fe)
    {
      return new Typeface((FontFamily)fe.GetValue(TextBlock.FontFamilyProperty),
                          (FontStyle)fe.GetValue(TextBlock.FontStyleProperty),
                          (FontWeight)fe.GetValue(TextBlock.FontWeightProperty),
                          (FontStretch)fe.GetValue(TextBlock.FontStretchProperty));
    }
    #endregion
    
    #region AddRange / Sequence
    public static void AddRange<T>(this ICollection<T> collection, IEnumerable<T> elements)
    {
      foreach (T e in elements)
        collection.Add(e);
    }
    
    /// <summary>
    /// Creates an IEnumerable with a single value.
    /// </summary>
    public static IEnumerable<T> Sequence<T>(T value)
    {
      yield return value;
    }
    #endregion
    
    #region XML reading
    /// <summary>
    /// Gets the value of the attribute, or null if the attribute does not exist.
    /// </summary>
    public static string GetAttributeOrNull(this XmlElement element, string attributeName)
    {
      XmlAttribute attr = element.GetAttributeNode(attributeName);
      return attr != null ? attr.Value : null;
    }
    
    /// <summary>
    /// Gets the value of the attribute as boolean, or null if the attribute does not exist.
    /// </summary>
    public static bool? GetBoolAttribute(this XmlElement element, string attributeName)
    {
      XmlAttribute attr = element.GetAttributeNode(attributeName);
      return attr != null ? (bool?)XmlConvert.ToBoolean(attr.Value) : null;
    }
    
    /// <summary>
    /// Gets the value of the attribute as boolean, or null if the attribute does not exist.
    /// </summary>
    public static bool? GetBoolAttribute(this XmlReader reader, string attributeName)
    {
      string attributeValue = reader.GetAttribute(attributeName);
      if (attributeValue == null)
        return null;
      else
        return XmlConvert.ToBoolean(attributeValue);
    }
    #endregion
    
    #region DPI independence
    public static Rect TransformToDevice(this Rect rect, Visual visual)
    {
      Matrix matrix = PresentationSource.FromVisual(visual).CompositionTarget.TransformToDevice;
      return Rect.Transform(rect, matrix);
    }
    
    public static Rect TransformFromDevice(this Rect rect, Visual visual)
    {
      Matrix matrix = PresentationSource.FromVisual(visual).CompositionTarget.TransformFromDevice;
      return Rect.Transform(rect, matrix);
    }
    
    public static Size TransformToDevice(this Size size, Visual visual)
    {
      Matrix matrix = PresentationSource.FromVisual(visual).CompositionTarget.TransformToDevice;
      return new Size(size.Width * matrix.M11, size.Height * matrix.M22);
    }
    
    public static Size TransformFromDevice(this Size size, Visual visual)
    {
      Matrix matrix = PresentationSource.FromVisual(visual).CompositionTarget.TransformFromDevice;
      return new Size(size.Width * matrix.M11, size.Height * matrix.M22);
    }
    
    public static Point TransformToDevice(this Point point, Visual visual)
    {
      Matrix matrix = PresentationSource.FromVisual(visual).CompositionTarget.TransformToDevice;
      return new Point(point.X * matrix.M11, point.Y * matrix.M22);
    }
    
    public static Point TransformFromDevice(this Point point, Visual visual)
    {
      Matrix matrix = PresentationSource.FromVisual(visual).CompositionTarget.TransformFromDevice;
      return new Point(point.X * matrix.M11, point.Y * matrix.M22);
    }
    #endregion
    
    #region System.Drawing <-> WPF conversions
    public static System.Drawing.Point ToSystemDrawing(this Point p)
    {
      return new System.Drawing.Point((int)p.X, (int)p.Y);
    }
    
    public static Point ToWpf(this System.Drawing.Point p)
    {
      return new Point(p.X, p.Y);
    }
    
    public static Size ToWpf(this System.Drawing.Size s)
    {
      return new Size(s.Width, s.Height);
    }
    
    public static Rect ToWpf(this System.Drawing.Rectangle rect)
    {
      return new Rect(rect.Location.ToWpf(), rect.Size.ToWpf());
    }
    #endregion
    
    public static IEnumerable<DependencyObject> VisualAncestorsAndSelf(this DependencyObject obj)
    {
      while (obj != null) {
        yield return obj;
        obj = VisualTreeHelper.GetParent(obj);
      }
    }
    
    [Conditional("DEBUG")]
    public static void CheckIsFrozen(Freezable f)
    {
      if (f != null && !f.IsFrozen)
        Debug.WriteLine("Performance warning: Not frozen: " + f.ToString());
    }
    
    [Conditional("DEBUG")]
    public static void Log(bool condition, string format, params object[] args)
    {
      if (condition) {
        string output = DateTime.Now.ToString("hh:MM:ss") + ": " + string.Format(format, args) + Environment.NewLine + Environment.StackTrace;
        Console.WriteLine(output);
        Debug.WriteLine(output);
      }
    }
  }
}