QuickLook/QuickLook.Plugin/QuickLook.Plugin.ImageViewer/Helper.cs

// Copyright © 2020 Paddy Xu
// 
// 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.IO;
using System.Reflection;
using System.Text;
using System.Windows.Media.Imaging;
using QuickLook.Common.Helpers;

namespace QuickLook.Plugin.ImageViewer
{
    internal class Helper
    {
        public static void DpiHack(BitmapSource img)
        {
            // a dirty hack... but is the fastest

            var newDpiX = (double) DisplayDeviceHelper.DefaultDpi * DisplayDeviceHelper.GetCurrentScaleFactor().Horizontal;
            var newDpiY = (double) DisplayDeviceHelper.DefaultDpi * DisplayDeviceHelper.GetCurrentScaleFactor().Vertical;

            var dpiX = img.GetType().GetField("_dpiX",
                BindingFlags.NonPublic | BindingFlags.Instance);
            var dpiY = img.GetType().GetField("_dpiY",
                BindingFlags.NonPublic | BindingFlags.Instance);
            dpiX?.SetValue(img, newDpiX);
            dpiY?.SetValue(img, newDpiY);
        }

        public static Uri FilePathToFileUrl(string filePath)
        {
            var uri = new StringBuilder();
            foreach (var v in filePath)
                if (v >= 'a' && v <= 'z' || v >= 'A' && v <= 'Z' || v >= '0' && v <= '9' ||
                    v == '+' || v == '/' || v == ':' || v == '.' || v == '-' || v == '_' || v == '~' ||
                    v > '\x80')
                    uri.Append(v);
                else if (v == Path.DirectorySeparatorChar || v == Path.AltDirectorySeparatorChar)
                    uri.Append('/');
                else
                    uri.Append($"%{(int) v:X2}");
            if (uri.Length >= 2 && uri[0] == '/' && uri[1] == '/') // UNC path
                uri.Insert(0, "file:");
            else
                uri.Insert(0, "file:///");

            try
            {
                return new Uri(uri.ToString());
            }
            catch
            {
                return null;
            }
        }
    }
}