ImageLoader now loads everything through IShellItemImageFactory::GetImage (#1836)

* Added thumbnail loader

* Deleted old shell icon extraction logic.
Refactored ImageLoader.Load to improve readibility.

* Moved error handling down into the API call itself

* Minor renamings in ImageLoader

* Load icons only for files that are not images. Fixes stutters when loading folders.

* Added the ability to load a full image through ImageLoader.
ImageLoader.Load now also has a "loadFullImage" parameter.

* Max image cache is now 5000 instead of 200.

* Added some commentaries on how thumbnails are loaded

Wox.Infrastructure/Image/ImageCache.cs

@@ -9,7 +9,7 @@ namespace Wox.Infrastructure.Image
     [Serializable]
     public class ImageCache
     {
-        private const int MaxCached = 200;
+        private const int MaxCached = 5000;
         public ConcurrentDictionary<string, int> Usage = new ConcurrentDictionary<string, int>();
         private readonly ConcurrentDictionary<string, ImageSource> _data = new ConcurrentDictionary<string, ImageSource>();
 

Wox.Infrastructure/Image/ImageLoader.cs

@@ -2,10 +2,7 @@
 using System.Collections.Concurrent;
 using System.IO;
 using System.Linq;
-using System.Runtime.InteropServices;
 using System.Threading.Tasks;
-using System.Windows;
-using System.Windows.Interop;
 using System.Windows.Media;
 using System.Windows.Media.Imaging;
 using Wox.Infrastructure.Logger;
@@ -19,7 +16,7 @@ namespace Wox.Infrastructure.Image
         private static BinaryStorage<ConcurrentDictionary<string, int>> _storage;
 
 
-        private static readonly string[] ImageExtions =
+        private static readonly string[] ImageExtensions =
         {
             ".png",
             ".jpg",
@@ -65,127 +62,93 @@ namespace Wox.Infrastructure.Image
             _storage.Save(ImageCache.Usage);
         }
         
-        private static ImageSource ShellIcon(string fileName)
+        public static ImageSource Load(string path, bool loadFullImage = false)
-        {
-            try
-            {
-                // http://blogs.msdn.com/b/oldnewthing/archive/2011/01/27/10120844.aspx
-                var shfi = new SHFILEINFO();
-                var himl = SHGetFileInfo(
-                    fileName,
-                    FILE_ATTRIBUTE_NORMAL,
-                    ref shfi,
-                    (uint)Marshal.SizeOf(shfi),
-                    SHGFI_SYSICONINDEX
-                );
-
-                if (himl != IntPtr.Zero)
-                {
-                    var hIcon = ImageList_GetIcon(himl, shfi.iIcon, ILD_NORMAL);
-                    // http://stackoverflow.com/questions/1325625/how-do-i-display-a-windows-file-icon-in-wpf
-                    var img = Imaging.CreateBitmapSourceFromHIcon(
-                        hIcon,
-                        Int32Rect.Empty,
-                        BitmapSizeOptions.FromEmptyOptions()
-                    );
-                    DestroyIcon(hIcon);
-                    return img;
-                }
-                else
-                {
-                    return new BitmapImage(new Uri(Constant.ErrorIcon));
-                }
-            }
-            catch (System.Exception e)
-            {
-                Log.Exception($"|ImageLoader.ShellIcon|can't get shell icon for <{fileName}>", e);
-                return ImageCache[Constant.ErrorIcon];
-            }
-        }
-
-        public static ImageSource Load(string path)
         {
             ImageSource image;
-            if (string.IsNullOrEmpty(path))
+            try
-            {
-                image = ImageCache[Constant.ErrorIcon];
-            }
-            else if (ImageCache.ContainsKey(path))
-            {
-                image = ImageCache[path];
-            }
-            else
             {
+                if (string.IsNullOrEmpty(path))
+                {
+                    return ImageCache[Constant.ErrorIcon];
+                }
+                if (ImageCache.ContainsKey(path))
+                {
+                    return ImageCache[path];
+                }
+                
                 if (path.StartsWith("data:", StringComparison.OrdinalIgnoreCase))
                 {
-                    image = new BitmapImage(new Uri(path));
+                    return new BitmapImage(new Uri(path));
                 }
-                else if (Path.IsPathRooted(path))
+
+                if (!Path.IsPathRooted(path))
                 {
-                    if (Directory.Exists(path))
+                    path = Path.Combine(Constant.ProgramDirectory, "Images", Path.GetFileName(path));
+                }
+               
+                if (Directory.Exists(path))
+                {
+                    /* Directories can also have thumbnails instead of shell icons.
+                     * Generating thumbnails for a bunch of folders while scrolling through
+                     * results from Everything makes a big impact on performance and 
+                     * Wox responsibility. 
+                     * - Solution: just load the icon
+                     */
+                    image = WindowsThumbnailProvider.GetThumbnail(path, Constant.ThumbnailSize,
+                        Constant.ThumbnailSize, ThumbnailOptions.IconOnly);
+                }
+                else if (File.Exists(path))
+                {
+                    var extension = Path.GetExtension(path).ToLower();
+                    if (ImageExtensions.Contains(extension))
                     {
-                        image = ShellIcon(path);
+                        if (loadFullImage)
-                    }
-                    else if (File.Exists(path))
-                    {
-                        var externsion = Path.GetExtension(path).ToLower();
-                        if (ImageExtions.Contains(externsion))
                         {
-                            image = new BitmapImage(new Uri(path));
+                            image = LoadFullImage(path);
                         }
                         else
                         {
-                            image = ShellIcon(path);
+                            /* Although the documentation for GetImage on MSDN indicates that 
+                             * if a thumbnail is available it will return one, this has proved to not
+                             * be the case in many situations while testing. 
+                             * - Solution: explicitly pass the ThumbnailOnly flag
+                             */
+                            image = WindowsThumbnailProvider.GetThumbnail(path, Constant.ThumbnailSize,
+                                Constant.ThumbnailSize, ThumbnailOptions.ThumbnailOnly);
                         }
                     }
                     else
                     {
-                        image = ImageCache[Constant.ErrorIcon];
+                        image = WindowsThumbnailProvider.GetThumbnail(path, Constant.ThumbnailSize,
-                        path = Constant.ErrorIcon;
+                            Constant.ThumbnailSize, ThumbnailOptions.None);
                     }
                 }
                 else
                 {
-                    var defaultDirectoryPath = Path.Combine(Constant.ProgramDirectory, "Images", Path.GetFileName(path));
+                    image = ImageCache[Constant.ErrorIcon];
-                    if (File.Exists(defaultDirectoryPath))
+                    path = Constant.ErrorIcon;
-                    {
-                        image = new BitmapImage(new Uri(defaultDirectoryPath));
-                    }
-                    else
-                    {
-                        image = ImageCache[Constant.ErrorIcon];
-                        path = Constant.ErrorIcon;
-                    }
                 }
                 ImageCache[path] = image;
                 image.Freeze();
             }
+            catch (System.Exception e)
+            {
+                Log.Exception($"|ImageLoader.Load|Failed to get thumbnail for {path}", e);
+
+                image = ImageCache[Constant.ErrorIcon];
+                ImageCache[path] = image;
+            }
             return image;
         }
 
-        private const int NAMESIZE = 80;
+        private static BitmapImage LoadFullImage(string path)
-        private const int MAX_PATH = 256;
-        private const uint SHGFI_SYSICONINDEX = 0x000004000; // get system icon index
-        private const uint FILE_ATTRIBUTE_NORMAL = 0x00000080;
-        private const uint ILD_NORMAL = 0x00000000;
-
-        [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)]
-        private struct SHFILEINFO
         {
-            readonly IntPtr hIcon;
+            BitmapImage image = new BitmapImage();
-            internal readonly int iIcon;
+            image.BeginInit();
-            readonly uint dwAttributes;
+            image.CacheOption = BitmapCacheOption.OnLoad;
-            [MarshalAs(UnmanagedType.ByValTStr, SizeConst = MAX_PATH)] readonly string szDisplayName;
+            image.UriSource = new Uri(path);
-            [MarshalAs(UnmanagedType.ByValTStr, SizeConst = NAMESIZE)] readonly string szTypeName;
+            image.EndInit();
+            return image;
         }
-        
-        [DllImport("Shell32.dll", CharSet = CharSet.Unicode)]
-        private static extern IntPtr SHGetFileInfo(string pszPath, uint dwFileAttributes, ref SHFILEINFO psfi, uint cbFileInfo, uint uFlags);
-
-        [DllImport("User32.dll")]
-        private static extern int DestroyIcon(IntPtr hIcon);
-
-        [DllImport("comctl32.dll")]
-        private static extern IntPtr ImageList_GetIcon(IntPtr himl, int i, uint flags);
     }
 }

Wox.Infrastructure/Image/ThumbnailReader.cs

@@ -0,0 +1,154 @@
+using System;
+using System.Runtime.InteropServices;
+using System.IO;
+using System.Windows.Interop;
+using System.Windows.Media.Imaging;
+using System.Windows;
+
+namespace Wox.Infrastructure.Image
+{
+    [Flags]
+    public enum ThumbnailOptions
+    {
+        None = 0x00,
+        BiggerSizeOk = 0x01,
+        InMemoryOnly = 0x02,
+        IconOnly = 0x04,
+        ThumbnailOnly = 0x08,
+        InCacheOnly = 0x10,
+    }
+
+    public class WindowsThumbnailProvider
+    {
+        // Based on https://stackoverflow.com/questions/21751747/extract-thumbnail-for-any-file-in-windows
+
+        private const string IShellItem2Guid = "7E9FB0D3-919F-4307-AB2E-9B1860310C93";
+
+        [DllImport("shell32.dll", CharSet = CharSet.Unicode, SetLastError = true)]
+        internal static extern int SHCreateItemFromParsingName(
+            [MarshalAs(UnmanagedType.LPWStr)] string path,
+            IntPtr pbc,
+            ref Guid riid,
+            [MarshalAs(UnmanagedType.Interface)] out IShellItem shellItem);
+
+        [DllImport("gdi32.dll")]
+        [return: MarshalAs(UnmanagedType.Bool)]
+        internal static extern bool DeleteObject(IntPtr hObject);
+
+        [ComImport]
+        [InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
+        [Guid("43826d1e-e718-42ee-bc55-a1e261c37bfe")]
+        internal interface IShellItem
+        {
+            void BindToHandler(IntPtr pbc,
+                [MarshalAs(UnmanagedType.LPStruct)]Guid bhid,
+                [MarshalAs(UnmanagedType.LPStruct)]Guid riid,
+                out IntPtr ppv);
+
+            void GetParent(out IShellItem ppsi);
+            void GetDisplayName(SIGDN sigdnName, out IntPtr ppszName);
+            void GetAttributes(uint sfgaoMask, out uint psfgaoAttribs);
+            void Compare(IShellItem psi, uint hint, out int piOrder);
+        };
+
+        internal enum SIGDN : uint
+        {
+            NORMALDISPLAY = 0,
+            PARENTRELATIVEPARSING = 0x80018001,
+            PARENTRELATIVEFORADDRESSBAR = 0x8001c001,
+            DESKTOPABSOLUTEPARSING = 0x80028000,
+            PARENTRELATIVEEDITING = 0x80031001,
+            DESKTOPABSOLUTEEDITING = 0x8004c000,
+            FILESYSPATH = 0x80058000,
+            URL = 0x80068000
+        }
+
+        internal enum HResult
+        {
+            Ok = 0x0000,
+            False = 0x0001,
+            InvalidArguments = unchecked((int)0x80070057),
+            OutOfMemory = unchecked((int)0x8007000E),
+            NoInterface = unchecked((int)0x80004002),
+            Fail = unchecked((int)0x80004005),
+            ExtractionFailed = unchecked((int)0x8004B200),
+            ElementNotFound = unchecked((int)0x80070490),
+            TypeElementNotFound = unchecked((int)0x8002802B),
+            NoObject = unchecked((int)0x800401E5),
+            Win32ErrorCanceled = 1223,
+            Canceled = unchecked((int)0x800704C7),
+            ResourceInUse = unchecked((int)0x800700AA),
+            AccessDenied = unchecked((int)0x80030005)
+        }
+
+        [ComImportAttribute()]
+        [GuidAttribute("bcc18b79-ba16-442f-80c4-8a59c30c463b")]
+        [InterfaceTypeAttribute(ComInterfaceType.InterfaceIsIUnknown)]
+        internal interface IShellItemImageFactory
+        {
+            [PreserveSig]
+            HResult GetImage(
+            [In, MarshalAs(UnmanagedType.Struct)] NativeSize size,
+            [In] ThumbnailOptions flags,
+            [Out] out IntPtr phbm);
+        }
+
+        [StructLayout(LayoutKind.Sequential)]
+        internal struct NativeSize
+        {
+            private int width;
+            private int height;
+
+            public int Width { set => width = value; }
+            public int Height { set => height = value; }
+        };
+
+
+        public static BitmapSource GetThumbnail(string fileName, int width, int height, ThumbnailOptions options)
+        {
+            IntPtr hBitmap = GetHBitmap(Path.GetFullPath(fileName), width, height, options);
+
+            try
+            {
+
+                return Imaging.CreateBitmapSourceFromHBitmap(hBitmap, IntPtr.Zero, Int32Rect.Empty, BitmapSizeOptions.FromEmptyOptions());
+            }
+            finally
+            {
+                // delete HBitmap to avoid memory leaks
+                DeleteObject(hBitmap);
+            }
+        }
+        
+        private static IntPtr GetHBitmap(string fileName, int width, int height, ThumbnailOptions options)
+        {
+            IShellItem nativeShellItem;
+            Guid shellItem2Guid = new Guid(IShellItem2Guid);
+            int retCode = SHCreateItemFromParsingName(fileName, IntPtr.Zero, ref shellItem2Guid, out nativeShellItem);
+
+            if (retCode != 0)
+                throw Marshal.GetExceptionForHR(retCode);
+
+            NativeSize nativeSize = new NativeSize
+            {
+                Width = width,
+                Height = height
+            };
+
+            IntPtr hBitmap;
+            HResult hr = ((IShellItemImageFactory)nativeShellItem).GetImage(nativeSize, options, out hBitmap);
+
+            // if extracting image thumbnail and failed, extract shell icon
+            if (options == ThumbnailOptions.ThumbnailOnly && hr == HResult.ExtractionFailed)
+            {
+                hr = ((IShellItemImageFactory) nativeShellItem).GetImage(nativeSize, ThumbnailOptions.IconOnly, out hBitmap);
+            }
+
+            Marshal.ReleaseComObject(nativeShellItem);
+
+            if (hr == HResult.Ok) return hBitmap;
+
+            throw new COMException($"Error while extracting thumbnail for {fileName}", Marshal.GetExceptionForHR((int)hr));
+        }
+    }
+}

Wox.Infrastructure/Wox.Infrastructure.csproj

@@ -72,6 +72,7 @@
     <Compile Include="Hotkey\KeyEvent.cs" />
     <Compile Include="Image\ImageCache.cs" />
     <Compile Include="Image\ImageLoader.cs" />
+    <Compile Include="Image\ThumbnailReader.cs" />
     <Compile Include="Logger\Log.cs" />
     <Compile Include="Storage\ISavable.cs" />
     <Compile Include="Storage\PluginJsonStorage.cs" />

Wox.Infrastructure/Wox.cs

@@ -20,6 +20,7 @@ namespace Wox.Infrastructure
         public const string Issue = "https://github.com/Wox-launcher/Wox/issues/new";
         public static readonly string Version = FileVersionInfo.GetVersionInfo(Assembly.Location.NonNull()).ProductVersion;
 
+        public static readonly int ThumbnailSize = 64;
         public static readonly string DefaultIcon = Path.Combine(ProgramDirectory, "Images", "app.png");
         public static readonly string ErrorIcon = Path.Combine(ProgramDirectory, "Images", "app_error.png");