manifestimages.cs source code in C# .NET

                        Code:
                         / 4.0 / 4.0 / untmp / DEVDIV_TFS / Dev10 / Releases / RTMRel / ndp / cdf / src / NetFx40 / Tools / System.Activities.Presentation / System / Activities / Presentation / Base / Core / Internal / manifestimages.cs / 1305376 / manifestimages.cs
                        
                        
                            //---------------------------------------------------------------- 
// Copyright (c) Microsoft Corporation.  All rights reserved.
//---------------------------------------------------------------
namespace System.Activities.Presentation.Internal
{ 
    using System;
    using System.IO; 
    using System.Reflection; 
    using System.Windows;
    using System.Windows.Controls; 
    using System.Windows.Markup;
    using System.Windows.Media.Imaging;
    using System.Diagnostics;
    using System.Runtime; 
    using System.Activities.Presentation;
 
    //  
    // Helper class that knows how to load up icons that live in assemblies and follow
    // our extensibility icon naming convention. 
    // 
    internal static class ManifestImages
    {
 
        private static readonly string[] SupportedExtensions = new string[] {
                ".png", ".xaml", ".bmp", ".gif", ".jpg", ".jpeg" 
            }; 

        //  
        // ----s open the assembly to which the specified Type belongs and tries
        // to find and return an image that follows the naming conventions of:
        //
        //     My.Namespace.MyControl.Icon.png 
        //
        // and matches the desired size most closely, if multiple such images are found. 
        //  
        // Type to look up
        // Desired size (may not be met) 
        // Null (if no image was found), Image instance (for non-Xaml images),
        // or object instance (for Xaml-instantiated structures)
        // if type is null
        public static object GetImage(Type type, Size desiredSize) 
        {
            if (type == null) 
            { 
                throw FxTrace.Exception.ArgumentNull("type");
            } 

            Assembly assembly = type.Assembly;
            string[] resourceNames = assembly.GetManifestResourceNames();
 
            if (resourceNames == null || resourceNames.Length == 0)
            { 
                return null; 
            }
 
            string fullTypeName = type.FullName;
            string typeName = type.Name;

            // Do a full namespace match first 
            ImageInfo bestMatch = FindBestMatch(type, assembly, resourceNames, desiredSize, delegate(string extensionlessResourceName)
            { 
                return fullTypeName.Equals(extensionlessResourceName); 
            });
 
            // Do a partial name match second, if full name didn't give us anything
            bestMatch = bestMatch ?? FindBestMatch(type, assembly, resourceNames, desiredSize, delegate(string extensionlessResourceName)
            {
                return extensionlessResourceName != null && extensionlessResourceName.EndsWith(typeName,StringComparison.Ordinal); 
            });
 
            if (bestMatch != null) 
            {
                return bestMatch.Image; 
            }

            return null;
        } 

        private static ImageInfo FindBestMatch( 
            Type type, 
            Assembly assembly,
            string[] resourceNames, 
            Size desiredSize,
            MatchNameDelegate matchName)
        {
 
            Fx.Assert(type != null, "FindBestMatch - type parameter should not be null");
            Fx.Assert(resourceNames != null && resourceNames.Length > 0, "resourceNames parameter should not be null"); 
            Fx.Assert(matchName != null, "matchName parameter should not be null"); 

            ImageInfo bestMatch = null; 

            for (int i = 0; i < resourceNames.Length; i++)
            {
 
                string extension = Path.GetExtension(resourceNames[i]);
 
                if (!IsExtensionSupported(extension)) 
                {
                    continue; 
                }

                if (!matchName(StripIconExtension(resourceNames[i])))
                { 
                    continue;
                } 
 
                ImageInfo info = ProcessResource(assembly, resourceNames[i]);
                if (info == null) 
                {
                    continue;
                }
 
                // Try to match the found resource to the requested size
                float sizeMatch = info.Match(desiredSize); 
 
                // Check for exact size match
                if (sizeMatch < float.Epsilon) 
                {
                    return info;
                }
 
                // Keep the best image found so far
                if (bestMatch == null || 
                    bestMatch.LastMatch > sizeMatch) 
                {
                    bestMatch = info; 
                }
            }

            return bestMatch; 
        }
 
        // Tries to load up an image 
        private static ImageInfo ProcessResource(Assembly assembly, string resourceName)
        { 
            Stream stream = assembly.GetManifestResourceStream(resourceName);
            if (stream == null)
            {
                return null; 
            }
 
            if (IsXamlContent(resourceName)) 
            {
                return new XamlImageInfo(stream); 
            }
            else
            {
                return new BitmapImageInfo(stream); 
            }
        } 
 
        // Checks to see whether the given extension is supported
        private static bool IsExtensionSupported(string extension) 
        {
            for (int i = 0; i < SupportedExtensions.Length; i++)
            {
                if (SupportedExtensions[i].Equals(extension, StringComparison.OrdinalIgnoreCase)) 
                {
                    return true; 
                } 
            }
 
            return false;
        }

        // Returns true if the passed in resource name ends in ".xaml" 
        private static bool IsXamlContent(string resourceName)
        { 
            return ".xaml".Equals(Path.GetExtension(resourceName), StringComparison.OrdinalIgnoreCase); 
        }
 
        // Strips ".Icon.ext" from a resource name
        private static string StripIconExtension(string resourceName)
        {
            if (resourceName == null) 
            {
                return null; 
            } 

            resourceName = Path.GetFileNameWithoutExtension(resourceName); 
            int dotIconIndex = resourceName.LastIndexOf(".Icon", StringComparison.OrdinalIgnoreCase);
            if (dotIconIndex > 0)
            {
                return resourceName.Substring(0, dotIconIndex); 
            }
 
            return null; 
        }
 
        private delegate bool MatchNameDelegate(string extensionlessResourceName);

        // Helper class that has information about an image
        private abstract class ImageInfo 
        {
 
            private float _lastMatch = 1; 

            protected ImageInfo() 
            {
            }

            public float LastMatch 
            { get { return _lastMatch; } }
            public abstract object Image 
            { get; } 
            protected abstract Size Size
            { get; } 
            protected abstract bool HasFixedSize
            { get; }

            // gets value range from 0 to 1: 0 == perfect match, 1 == complete opposite 
            public float Match(Size desiredSize)
            { 
 
                if (!this.HasFixedSize)
                { 
                    _lastMatch = 0;
                }
                else
                { 
                    Size actualSize = this.Size;
 
                    float desiredAspectRatio = Math.Max(float.Epsilon, GetAspectRatio(desiredSize)); 
                    float actualAspectRatio = Math.Max(float.Epsilon, GetAspectRatio(actualSize));
 
                    float desiredArea = Math.Max(float.Epsilon, GetArea(desiredSize));
                    float actualArea = Math.Max(float.Epsilon, GetArea(actualSize));

                    // these values range from 0 to 1, 1 being perfect match, 0 being not so perfect match 
                    float ratioDiff = desiredAspectRatio < actualAspectRatio ? desiredAspectRatio / actualAspectRatio : actualAspectRatio / desiredAspectRatio;
                    float areaDiff = desiredArea < actualArea ? desiredArea / actualArea : actualArea / desiredArea; 
 
                    float diff = ratioDiff * areaDiff;
 
                    _lastMatch = Math.Min(1f, Math.Max(0f, 1f - diff));
                }

                return _lastMatch; 
            }
 
            private static float GetAspectRatio(Size size) 
            {
                if (size.Height < float.Epsilon) 
                {
                    return 0;
                }
 
                return (float)(size.Width / size.Height);
            } 
 
            private static float GetArea(Size size)
            { 
                return (float)(size.Width * size.Height);
            }
        }
 
        // Helper class that knows how to deal with Xaml
        private class XamlImageInfo : ImageInfo 
        { 

            private object _image; 

            public XamlImageInfo(Stream stream)
            {
                _image = XamlReader.Load(stream); 
            }
 
            public override object Image 
            {
                get { return _image; } 
            }

            protected override Size Size
            { 
                get { return Size.Empty; }
            } 
 
            protected override bool HasFixedSize
            { 
                get { return false; }
            }
        }
 
        // Helper class that knows how to deal with bitmaps
        private class BitmapImageInfo : ImageInfo 
        { 

            private Image _image; 
            private Size _size;

            public BitmapImageInfo(Stream stream)
            { 
                BitmapImage bmp = new BitmapImage();
                bmp.BeginInit(); 
                bmp.StreamSource = stream; 
                bmp.EndInit();
 
                _image = new Image();
                _image.Source = bmp;

                _size = new Size(bmp.Width, bmp.Height); 
            }
 
            public override object Image 
            {
                get { return _image; } 
            }

            protected override Size Size
            { 
                get { return _size; }
            } 
 
            protected override bool HasFixedSize
            { 
                get { return true; }
            }
        }
    } 
}

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
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manifestimages.cs source code in C# .NET

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