Converters.cs

// Copyright © 2020 Paddy Xu, Frank Becker
// 
// This file is part of QuickLook program.
// 
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
// 
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
// 
// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

using System;
using System.Globalization;
using System.Runtime.InteropServices;
using System.Windows;
using System.Windows.Data;
using System.Windows.Interop;
using System.Windows.Media.Imaging;
using QuickLook.Common.ExtensionMethods;

namespace QuickLook.Plugin.FolderViewer
{
    public class Percent100ToVisibilityVisibleConverter : DependencyObject, IValueConverter
    {
        public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
        {
            if (value == null)
                value = 0;

            var percent = (double)value;
            return Math.Abs(percent - 100) < 0.00001 ? Visibility.Visible : Visibility.Collapsed;
        }

        public object ConvertBack(object value, Type targetTypes, object parameter, CultureInfo culture)
        {
            throw new NotImplementedException();
        }
    }

    public class Percent100ToVisibilityCollapsedConverter : DependencyObject, IValueConverter
    {
        public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
        {
            if (value == null)
                value = 0;

            var percent = (double)value;
            return Math.Abs(percent - 100) < 0.00001 ? Visibility.Collapsed : Visibility.Visible;
        }

        public object ConvertBack(object value, Type targetTypes, object parameter, CultureInfo culture)
        {
            throw new NotImplementedException();
        }
    }

    public class SizePrettyPrintConverter : DependencyObject, IMultiValueConverter
    {
        public object Convert(object[] values, Type targetType, object parameter, CultureInfo culture)
        {
            var size = (ulong)values[0];
            var isFolder = (bool)values[1];

            return isFolder ? "" : ((long)size).ToPrettySize(2);
        }

        public object[] ConvertBack(object value, Type[] targetTypes, object parameter, CultureInfo culture)
        {
            throw new NotImplementedException();
        }
    }

    public class DatePrintConverter : DependencyObject, IMultiValueConverter
    {
        public object Convert(object[] values, Type targetType, object parameter, CultureInfo culture)
        {
            var date = (DateTime)values[0];
            var isFolder = (bool)values[1];

            return isFolder ? "" : date.ToString(CultureInfo.CurrentCulture);
        }

        public object[] ConvertBack(object value, Type[] targetTypes, object parameter, CultureInfo culture)
        {
            throw new NotImplementedException();
        }
    }

    public class FileToIconConverter : DependencyObject, IMultiValueConverter
    {
        // FB: I have no idea what I'm doing here...
        // A bunch gratuitously copied from WindowsThumbnailProvider.cs

        [Flags]
        internal enum ThumbnailOptions
        {
            None = 0x00,
            BiggerSizeOk = 0x01,
            InMemoryOnly = 0x02,
            IconOnly = 0x04,
            ThumbnailOnly = 0x08,
            InCacheOnly = 0x10,
            IconBackground = 0x80,
            ScaleUp = 0x100
        }

        internal enum HResult
        {
            Ok = 0x0000,
            False = 0x0001,
            InvalidArguments = unchecked((int)0x80070057),
            OutOfMemory = unchecked((int)0x8007000E),
            NoInterface = unchecked((int)0x80004002),
            Fail = unchecked((int)0x80004005),
            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)
        }

        internal enum SIGDN : uint
        {
            NORMALDISPLAY = 0,
            PARENTRELATIVEPARSING = 0x80018001,
            PARENTRELATIVEFORADDRESSBAR = 0x8001c001,
            DESKTOPABSOLUTEPARSING = 0x80028000,
            PARENTRELATIVEEDITING = 0x80031001,
            DESKTOPABSOLUTEEDITING = 0x8004c000,
            FILESYSPATH = 0x80058000,
            URL = 0x80068000
        }

        [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);
        }

        [ComImport]
        [Guid("bcc18b79-ba16-442f-80c4-8a59c30c463b")]
        [InterfaceType(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;
            }
        }

        private const string IShellItem2Guid = "7E9FB0D3-919F-4307-AB2E-9B1860310C93";

        [DllImport("shell32.dll", CharSet = CharSet.Unicode, SetLastError = true)]
        private static extern int SHCreateItemFromParsingName(
            [MarshalAs(UnmanagedType.LPWStr)] string path,
            // The following parameter is not used - binding context.
            IntPtr pbc,
            ref Guid riid,
            [MarshalAs(UnmanagedType.Interface)] out IShellItem shellItem);

        [DllImport("gdi32.dll", EntryPoint = "DeleteObject")]
        [return: MarshalAs(UnmanagedType.Bool)]
        public static extern bool DeleteObject([In] IntPtr hObject);

        private static IntPtr GetHBitmap(string fileName, int width, int height, ThumbnailOptions options)
        {
            var shellItem2Guid = new Guid(IShellItem2Guid);
            var retCode =
                SHCreateItemFromParsingName(fileName, IntPtr.Zero, ref shellItem2Guid, out var nativeShellItem);

            if (retCode != 0)
                return IntPtr.Zero;

            var nativeSize = new NativeSize
            {
                Width = width,
                Height = height
            };

            var hr = ((IShellItemImageFactory)nativeShellItem).GetImage(nativeSize, options, out var hBitmap);

            Marshal.ReleaseComObject(nativeShellItem);

            return hr == HResult.Ok ? hBitmap : IntPtr.Zero;
        }

        public object Convert(object[] values, Type targetType, object parameter, CultureInfo culture)
        {
            var fullPath = (string)values[0];

            // HBitmap to BitmapSource - See https://stackoverflow.com/a/35274172
            var bitmapHandle = GetHBitmap(fullPath, 16, 16, ThumbnailOptions.None);
            try
            {
                return Imaging.CreateBitmapSourceFromHBitmap(bitmapHandle, IntPtr.Zero, Int32Rect.Empty, BitmapSizeOptions.FromEmptyOptions());
            }
            finally { DeleteObject(bitmapHandle); }
        }

        public object[] ConvertBack(object value, Type[] targetTypes, object parameter, CultureInfo culture)
        {
            throw new NotImplementedException();
        }
    }
}