Go back from Webkit to IE render engine

QuickLook.Plugin/QuickLook.Plugin.HtmlViewer/Helper.cs

@@ -0,0 +1,50 @@
+using System.IO;
+using System.Text;
+using Microsoft.Win32;
+
+namespace QuickLook.Plugin.HtmlViewer
+{
+    internal static class Helper
+    {
+        public static string 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 > '\xFF')
+                    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:///");
+            return uri.ToString();
+        }
+
+        public static void SetBrowserFeatureControl()
+        {
+            var exeName = Path.GetFileName(App.AppFullPath);
+
+            // use latest engine
+            SetBrowserFeatureControlKey("FEATURE_BROWSER_EMULATION", exeName, 0);
+            //
+            SetBrowserFeatureControlKey("FEATURE_GPU_RENDERING", exeName, 0);
+            // turn on hi-dpi mode
+            SetBrowserFeatureControlKey("FEATURE_96DPI_PIXEL", exeName, 1);
+        }
+
+        private static void SetBrowserFeatureControlKey(string feature, string appName, uint value)
+        {
+            using (var key = Registry.CurrentUser.CreateSubKey(
+                string.Concat(@"Software\Microsoft\Internet Explorer\Main\FeatureControl\", feature),
+                RegistryKeyPermissionCheck.ReadWriteSubTree))
+            {
+                key?.SetValue(appName, value, RegistryValueKind.DWord);
+            }
+        }
+    }
+}

QuickLook.Plugin/QuickLook.Plugin.HtmlViewer/JsDialogHandler.cs

@@ -1,36 +0,0 @@
-// Copyright © 2010-2017 The CefSharp Authors. All rights reserved.
-//
-// Use of this source code is governed by a BSD-style license that can be found in the LICENSE file.
-
-using CefSharp;
-
-namespace QuickLook.Plugin.HtmlViewer
-{
-    public class JsDialogHandler : IJsDialogHandler
-    {
-        public bool OnJSDialog(IWebBrowser browserControl, IBrowser browser, string originUrl,
-            CefJsDialogType dialogType, string messageText, string defaultPromptText, IJsDialogCallback callback,
-            ref bool suppressMessage)
-        {
-            return true;
-        }
-
-        public bool OnJSBeforeUnload(IWebBrowser browserControl, IBrowser browser, string message, bool isReload,
-            IJsDialogCallback callback)
-        {
-            //NOTE: No need to execute the callback if you return false
-            // callback.Continue(true);
-
-            //NOTE: Returning false will trigger the default behaviour, you need to return true to handle yourself.
-            return true;
-        }
-
-        public void OnResetDialogState(IWebBrowser browserControl, IBrowser browser)
-        {
-        }
-
-        public void OnDialogClosed(IWebBrowser browserControl, IBrowser browser)
-        {
-        }
-    }
-}

QuickLook.Plugin/QuickLook.Plugin.HtmlViewer/MenuHandler.cs

@@ -1,35 +0,0 @@
-// Copyright © 2010-2017 The CefSharp Authors. All rights reserved.
-//
-// Use of this source code is governed by a BSD-style license that can be found in the LICENSE file.
-
-using CefSharp;
-
-namespace QuickLook.Plugin.HtmlViewer
-{
-    internal class MenuHandler : IContextMenuHandler
-    {
-        public void OnBeforeContextMenu(IWebBrowser browserControl, IBrowser browser, IFrame frame,
-            IContextMenuParams parameters,
-            IMenuModel model)
-        {
-        }
-
-        public bool OnContextMenuCommand(IWebBrowser browserControl, IBrowser browser, IFrame frame,
-            IContextMenuParams parameters,
-            CefMenuCommand commandId, CefEventFlags eventFlags)
-        {
-            return false;
-        }
-
-        public void OnContextMenuDismissed(IWebBrowser browserControl, IBrowser browser, IFrame frame)
-        {
-        }
-
-        public bool RunContextMenu(IWebBrowser browserControl, IBrowser browser, IFrame frame,
-            IContextMenuParams parameters,
-            IMenuModel model, IRunContextMenuCallback callback)
-        {
-            return true;
-        }
-    }
-}

QuickLook.Plugin/QuickLook.Plugin.HtmlViewer/Plugin.cs

@@ -1,15 +1,16 @@
 using System;
 using System.IO;
 using System.Windows;
+using System.Windows.Threading;
 
 namespace QuickLook.Plugin.HtmlViewer
 {
     public class Plugin : IViewer
     {
-        private WebkitPanel _panel;
+        private WebpagePanel _panel;
 
         public int Priority => int.MaxValue;
-        public bool AllowsTransparency => true;
+        public bool AllowsTransparency => false;
 
         public bool CanHandle(string path)
         {
@@ -36,12 +37,12 @@ namespace QuickLook.Plugin.HtmlViewer
 
         public void View(string path, ContextObject context)
         {
-            _panel = new WebkitPanel();
+            _panel = new WebpagePanel();
             context.ViewerContent = _panel;
             context.Title = Path.IsPathRooted(path) ? Path.GetFileName(path) : path;
 
             _panel.Navigate(path);
-            context.IsBusy = false;
+            _panel.Dispatcher.Invoke(() => { context.IsBusy = false; }, DispatcherPriority.Loaded);
         }
 
         public void Cleanup()

QuickLook.Plugin/QuickLook.Plugin.HtmlViewer/QuickLook.Plugin.HtmlViewer.csproj

@@ -35,20 +35,10 @@
     <CodeAnalysisRuleSet>MinimumRecommendedRules.ruleset</CodeAnalysisRuleSet>
   </PropertyGroup>
   <ItemGroup>
-    <Reference Include="CefSharp, Version=57.0.0.0, Culture=neutral, PublicKeyToken=40c4b6fc221f4138, processorArchitecture=x86">
-      <SpecificVersion>False</SpecificVersion>
-      <HintPath>References\CefSharp.dll</HintPath>
-    </Reference>
-    <Reference Include="CefSharp.Core, Version=57.0.0.0, Culture=neutral, PublicKeyToken=40c4b6fc221f4138, processorArchitecture=x86">
-      <SpecificVersion>False</SpecificVersion>
-      <HintPath>References\CefSharp.Core.dll</HintPath>
-    </Reference>
-    <Reference Include="CefSharp.Wpf, Version=57.0.0.0, Culture=neutral, PublicKeyToken=40c4b6fc221f4138, processorArchitecture=x86">
-      <SpecificVersion>False</SpecificVersion>
-      <HintPath>References\CefSharp.Wpf.dll</HintPath>
-    </Reference>
+    <Reference Include="Microsoft.CSharp" />
     <Reference Include="System" />
     <Reference Include="System.Core" />
+    <Reference Include="System.Windows.Forms" />
     <Reference Include="System.Xaml">
       <RequiredTargetFramework>4.0</RequiredTargetFramework>
     </Reference>
@@ -57,20 +47,18 @@
     <Reference Include="PresentationFramework" />
   </ItemGroup>
   <ItemGroup>
-    <Page Include="WebkitPanel.xaml">
+    <Compile Include="WpfBrowserWrapper.cs" />
+    <Page Include="WebpagePanel.xaml">
       <Generator>MSBuild:Compile</Generator>
       <SubType>Designer</SubType>
     </Page>
     <Compile Include="..\..\GitVersion.cs">
       <Link>Properties\GitVersion.cs</Link>
     </Compile>
-    <Compile Include="JsDialogHandler.cs" />
-    <Compile Include="MenuHandler.cs" />
     <Compile Include="Plugin.cs" />
-    <Compile Include="RequestHandler.cs" />
-    <Compile Include="UrlHelper.cs" />
-    <Compile Include="WebkitPanel.xaml.cs">
-      <DependentUpon>WebkitPanel.xaml</DependentUpon>
+    <Compile Include="Helper.cs" />
+    <Compile Include="WebpagePanel.xaml.cs">
+      <DependentUpon>WebpagePanel.xaml</DependentUpon>
       <SubType>Code</SubType>
     </Compile>
   </ItemGroup>
@@ -78,38 +66,6 @@
     <Compile Include="Properties\AssemblyInfo.cs">
       <SubType>Code</SubType>
     </Compile>
-    <ContentWithTargetPath Include="CefSharp\cef.pak">
-      <CopyToOutputDirectory>Always</CopyToOutputDirectory>
-      <TargetPath>cef.pak</TargetPath>
-    </ContentWithTargetPath>
-    <ContentWithTargetPath Include="CefSharp\cef_100_percent.pak">
-      <CopyToOutputDirectory>Always</CopyToOutputDirectory>
-      <TargetPath>cef_100_percent.pak</TargetPath>
-    </ContentWithTargetPath>
-    <ContentWithTargetPath Include="CefSharp\cef_200_percent.pak">
-      <CopyToOutputDirectory>Always</CopyToOutputDirectory>
-      <TargetPath>cef_200_percent.pak</TargetPath>
-    </ContentWithTargetPath>
-    <ContentWithTargetPath Include="CefSharp\cef_extensions.pak">
-      <CopyToOutputDirectory>Always</CopyToOutputDirectory>
-      <TargetPath>cef_extensions.pak</TargetPath>
-    </ContentWithTargetPath>
-    <ContentWithTargetPath Include="CefSharp\icudtl.dat">
-      <CopyToOutputDirectory>Always</CopyToOutputDirectory>
-      <TargetPath>icudtl.dat</TargetPath>
-    </ContentWithTargetPath>
-    <ContentWithTargetPath Include="CefSharp\locales\en-US.pak">
-      <CopyToOutputDirectory>Always</CopyToOutputDirectory>
-      <TargetPath>locales\en-US.pak</TargetPath>
-    </ContentWithTargetPath>
-    <ContentWithTargetPath Include="CefSharp\natives_blob.bin">
-      <CopyToOutputDirectory>Always</CopyToOutputDirectory>
-      <TargetPath>natives_blob.bin</TargetPath>
-    </ContentWithTargetPath>
-    <ContentWithTargetPath Include="CefSharp\snapshot_blob.bin">
-      <CopyToOutputDirectory>Always</CopyToOutputDirectory>
-      <TargetPath>snapshot_blob.bin</TargetPath>
-    </ContentWithTargetPath>
   </ItemGroup>
   <ItemGroup>
     <ProjectReference Include="..\..\QuickLook\QuickLook.csproj">
@@ -119,38 +75,15 @@
     </ProjectReference>
   </ItemGroup>
   <ItemGroup>
-    <ContentWithTargetPath Include="CefSharp\CefSharp.BrowserSubprocess.Core.dll">
-      <CopyToOutputDirectory>Always</CopyToOutputDirectory>
-      <TargetPath>CefSharp.BrowserSubprocess.Core.dll</TargetPath>
-    </ContentWithTargetPath>
-    <ContentWithTargetPath Include="CefSharp\CefSharp.BrowserSubprocess.exe">
-      <CopyToOutputDirectory>Always</CopyToOutputDirectory>
-      <TargetPath>CefSharp.BrowserSubprocess.exe</TargetPath>
-    </ContentWithTargetPath>
-    <ContentWithTargetPath Include="CefSharp\chrome_elf.dll">
-      <CopyToOutputDirectory>Always</CopyToOutputDirectory>
-      <TargetPath>chrome_elf.dll</TargetPath>
-    </ContentWithTargetPath>
-    <ContentWithTargetPath Include="CefSharp\d3dcompiler_47.dll">
-      <CopyToOutputDirectory>Always</CopyToOutputDirectory>
-      <TargetPath>d3dcompiler_47.dll</TargetPath>
-    </ContentWithTargetPath>
-    <ContentWithTargetPath Include="CefSharp\libcef.dll">
-      <CopyToOutputDirectory>Always</CopyToOutputDirectory>
-      <TargetPath>libcef.dll</TargetPath>
-    </ContentWithTargetPath>
-    <ContentWithTargetPath Include="CefSharp\libEGL.dll">
-      <CopyToOutputDirectory>Always</CopyToOutputDirectory>
-      <TargetPath>libEGL.dll</TargetPath>
-    </ContentWithTargetPath>
-    <ContentWithTargetPath Include="CefSharp\libGLESv2.dll">
-      <CopyToOutputDirectory>Always</CopyToOutputDirectory>
-      <TargetPath>libGLESv2.dll</TargetPath>
-    </ContentWithTargetPath>
-    <ContentWithTargetPath Include="CefSharp\widevinecdmadapter.dll">
-      <CopyToOutputDirectory>Always</CopyToOutputDirectory>
-      <TargetPath>widevinecdmadapter.dll</TargetPath>
-    </ContentWithTargetPath>
+    <COMReference Include="SHDocVw">
+      <Guid>{EAB22AC0-30C1-11CF-A7EB-0000C05BAE0B}</Guid>
+      <VersionMajor>1</VersionMajor>
+      <VersionMinor>1</VersionMinor>
+      <Lcid>0</Lcid>
+      <WrapperTool>tlbimp</WrapperTool>
+      <Isolated>False</Isolated>
+      <EmbedInteropTypes>True</EmbedInteropTypes>
+    </COMReference>
   </ItemGroup>
   <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
 </Project>

QuickLook.Plugin/QuickLook.Plugin.HtmlViewer/RequestHandler.cs

@@ -1,113 +0,0 @@
-// Copyright © 2010-2017 The CefSharp Authors. All rights reserved.
-//
-// Use of this source code is governed by a BSD-style license that can be found in the LICENSE file.
-
-using System.Security.Cryptography.X509Certificates;
-using CefSharp;
-
-namespace QuickLook.Plugin.HtmlViewer
-{
-    public class RequestHandler : IRequestHandler
-    {
-        bool IRequestHandler.OnBeforeBrowse(IWebBrowser browserControl, IBrowser browser, IFrame frame,
-            IRequest request, bool isRedirect)
-        {
-            return request.TransitionType != TransitionType.Explicit;
-        }
-
-        bool IRequestHandler.OnOpenUrlFromTab(IWebBrowser browserControl, IBrowser browser, IFrame frame,
-            string targetUrl, WindowOpenDisposition targetDisposition, bool userGesture)
-        {
-            return OnOpenUrlFromTab(browserControl, browser, frame, targetUrl, targetDisposition, userGesture);
-        }
-
-        bool IRequestHandler.OnCertificateError(IWebBrowser browserControl, IBrowser browser, CefErrorCode errorCode,
-            string requestUrl, ISslInfo sslInfo, IRequestCallback callback)
-        {
-            callback.Dispose();
-            return false;
-        }
-
-        void IRequestHandler.OnPluginCrashed(IWebBrowser browserControl, IBrowser browser, string pluginPath)
-        {
-        }
-
-        CefReturnValue IRequestHandler.OnBeforeResourceLoad(IWebBrowser browserControl, IBrowser browser, IFrame frame,
-            IRequest request, IRequestCallback callback)
-        {
-            return CefReturnValue.Continue;
-        }
-
-        bool IRequestHandler.GetAuthCredentials(IWebBrowser browserControl, IBrowser browser, IFrame frame,
-            bool isProxy, string host, int port, string realm, string scheme, IAuthCallback callback)
-        {
-            callback.Dispose();
-            return false;
-        }
-
-        bool IRequestHandler.OnSelectClientCertificate(IWebBrowser browserControl, IBrowser browser, bool isProxy,
-            string host, int port, X509Certificate2Collection certificates, ISelectClientCertificateCallback callback)
-        {
-            //NOTE: If you do not wish to implement this method returning false is the default behaviour
-            // We also suggest you explicitly Dispose of the callback as it wraps an unmanaged resource.
-
-            return OnSelectClientCertificate(browserControl, browser, isProxy, host, port, certificates, callback);
-        }
-
-        void IRequestHandler.OnRenderProcessTerminated(IWebBrowser browserControl, IBrowser browser,
-            CefTerminationStatus status)
-        {
-        }
-
-        bool IRequestHandler.OnQuotaRequest(IWebBrowser browserControl, IBrowser browser, string originUrl,
-            long newSize, IRequestCallback callback)
-        {
-            callback.Dispose();
-            return false;
-        }
-
-        void IRequestHandler.OnResourceRedirect(IWebBrowser browserControl, IBrowser browser, IFrame frame,
-            IRequest request, IResponse response, ref string newUrl)
-        {
-        }
-
-        bool IRequestHandler.OnProtocolExecution(IWebBrowser browserControl, IBrowser browser, string url)
-        {
-            return false;
-        }
-
-        void IRequestHandler.OnRenderViewReady(IWebBrowser browserControl, IBrowser browser)
-        {
-        }
-
-        bool IRequestHandler.OnResourceResponse(IWebBrowser browserControl, IBrowser browser, IFrame frame,
-            IRequest request, IResponse response)
-        {
-            return false;
-        }
-
-        IResponseFilter IRequestHandler.GetResourceResponseFilter(IWebBrowser browserControl, IBrowser browser,
-            IFrame frame, IRequest request, IResponse response)
-        {
-            return null;
-        }
-
-        void IRequestHandler.OnResourceLoadComplete(IWebBrowser browserControl, IBrowser browser, IFrame frame,
-            IRequest request, IResponse response, UrlRequestStatus status, long receivedContentLength)
-        {
-        }
-
-        protected virtual bool OnOpenUrlFromTab(IWebBrowser browserControl, IBrowser browser, IFrame frame,
-            string targetUrl, WindowOpenDisposition targetDisposition, bool userGesture)
-        {
-            return false;
-        }
-
-        protected virtual bool OnSelectClientCertificate(IWebBrowser browserControl, IBrowser browser, bool isProxy,
-            string host, int port, X509Certificate2Collection certificates, ISelectClientCertificateCallback callback)
-        {
-            callback.Dispose();
-            return false;
-        }
-    }
-}

QuickLook.Plugin/QuickLook.Plugin.HtmlViewer/UrlHelper.cs

@@ -1,27 +0,0 @@
-using System.IO;
-using System.Text;
-
-namespace QuickLook.Plugin.HtmlViewer
-{
-    internal static class UrlHelper
-    {
-        internal static string 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 > '\xFF')
-                    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:///");
-            return uri.ToString();
-        }
-    }
-}

QuickLook.Plugin/QuickLook.Plugin.HtmlViewer/WebkitPanel.xaml.cs

@@ -1,63 +0,0 @@
-using System;
-using System.Collections.Generic;
-using System.IO;
-using System.Reflection;
-using System.Windows;
-using System.Windows.Controls;
-using CefSharp;
-
-namespace QuickLook.Plugin.HtmlViewer
-{
-    /// <summary>
-    ///     Interaction logic for UserControl1.xaml
-    /// </summary>
-    public partial class WebkitPanel : UserControl, IDisposable
-    {
-        private readonly string _cefPath =
-            Path.Combine(Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location));
-
-        public WebkitPanel()
-        {
-            var libraryLoader = new CefLibraryHandle(Path.Combine(_cefPath, "libcef.dll"));
-
-            if (!Cef.IsInitialized)
-                Cef.Initialize(new CefSettings
-                {
-                    BrowserSubprocessPath = Path.Combine(_cefPath, "CefSharp.BrowserSubprocess.exe"),
-                    LocalesDirPath = Path.Combine(_cefPath, "locales"),
-                    ResourcesDirPath = _cefPath,
-                    LogSeverity = LogSeverity.Disable,
-                    CefCommandLineArgs = {new KeyValuePair<string, string>("disable-gpu", "1")}
-                });
-
-            InitializeComponent();
-
-            Application.Current.Exit += (sender, e) => Cef.Shutdown();
-
-            browser.RequestHandler = new RequestHandler();
-            browser.MenuHandler = new MenuHandler();
-            browser.JsDialogHandler = new JsDialogHandler();
-        }
-
-        public void Dispose()
-        {
-            browser?.Dispose();
-        }
-
-        public void Navigate(string path)
-        {
-            if (Path.IsPathRooted(path))
-                path = UrlHelper.FilePathToFileUrl(path);
-
-            browser.IsBrowserInitializedChanged += (sender, e) => browser.Load(path);
-        }
-
-        public void LoadHtml(string html, string path)
-        {
-            if (Path.IsPathRooted(path))
-                path = UrlHelper.FilePathToFileUrl(path);
-
-            browser.IsBrowserInitializedChanged += (sender, e) => browser.LoadHtml(html, path);
-        }
-    }
-}

QuickLook.Plugin/QuickLook.Plugin.HtmlViewer/WebpagePanel.xaml

@@ -1,13 +1,12 @@
-<UserControl x:Class="QuickLook.Plugin.HtmlViewer.WebkitPanel"
+<UserControl x:Class="QuickLook.Plugin.HtmlViewer.WebpagePanel"
              xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
              xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
              xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
              xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
              xmlns:local="clr-namespace:QuickLook.Plugin.HtmlViewer"
-             xmlns:cef="clr-namespace:CefSharp.Wpf;assembly=CefSharp.Wpf"
              mc:Ignorable="d"
              d:DesignHeight="300" d:DesignWidth="300">
     <Grid>
-        <cef:ChromiumWebBrowser x:Name="browser" />
+        <local:WpfWebBrowserWrapper x:Name="browser" Zoom="200" />
     </Grid>
 </UserControl>

QuickLook.Plugin/QuickLook.Plugin.HtmlViewer/WebpagePanel.xaml.cs

@@ -0,0 +1,42 @@
+using System;
+using System.IO;
+using System.Text;
+using System.Windows.Controls;
+using System.Windows.Threading;
+
+namespace QuickLook.Plugin.HtmlViewer
+{
+    /// <summary>
+    ///     Interaction logic for UserControl1.xaml
+    /// </summary>
+    public partial class WebpagePanel : UserControl, IDisposable
+    {
+        public WebpagePanel()
+        {
+            InitializeComponent();
+
+            Helper.SetBrowserFeatureControl();
+        }
+
+        public void Dispose()
+        {
+            browser?.Dispose();
+            browser = null;
+        }
+
+        public void Navigate(string path)
+        {
+            if (Path.IsPathRooted(path))
+                path = Helper.FilePathToFileUrl(path);
+
+            browser.Dispatcher.Invoke(() => { browser.Navigate(path); }, DispatcherPriority.Loaded);
+        }
+
+        public void LoadHtml(string html)
+        {
+            var s = new MemoryStream(Encoding.UTF8.GetBytes(html ?? ""));
+
+            browser.Dispatcher.Invoke(() => { browser.Navigate(s); }, DispatcherPriority.Loaded);
+        }
+    }
+}

QuickLook.Plugin/QuickLook.Plugin.HtmlViewer/WpfBrowserWrapper.cs

@@ -0,0 +1,230 @@
+using System;
+using System.Diagnostics;
+using System.IO;
+using System.Reflection;
+using System.Runtime.InteropServices;
+using System.Windows;
+using System.Windows.Controls;
+using System.Windows.Forms;
+using System.Windows.Navigation;
+using SHDocVw;
+using HorizontalAlignment = System.Windows.HorizontalAlignment;
+using WebBrowser = System.Windows.Controls.WebBrowser;
+
+namespace QuickLook.Plugin.HtmlViewer
+{
+    /// <summary>
+    ///     Class wraps a Browser (which itself is a bad designed WPF control) and presents itself as
+    ///     a better designed WPF control. For example provides a bindable source property or commands.
+    /// </summary>
+    public class WpfWebBrowserWrapper : ContentControl, IDisposable
+    {
+        private static readonly Guid SidSWebBrowserApp = new Guid("0002DF05-0000-0000-C000-000000000046");
+
+        private WebBrowser _innerBrowser;
+        private bool _loaded;
+        private int _zoom;
+
+        public WpfWebBrowserWrapper()
+        {
+            _innerBrowser = new WebBrowser
+            {
+                HorizontalAlignment = HorizontalAlignment.Stretch,
+                VerticalAlignment = VerticalAlignment.Stretch
+            };
+
+            Content = _innerBrowser;
+            _innerBrowser.Navigated += InnerBrowserNavigated;
+            _innerBrowser.Navigating += InnerBrowserNavigating;
+            _innerBrowser.LoadCompleted += InnerBrowserLoadCompleted;
+            _innerBrowser.Loaded += InnerBrowserLoaded;
+            _innerBrowser.SizeChanged += InnerBrowserSizeChanged;
+        }
+
+        public string Url { get; private set; }
+
+        public int Zoom
+        {
+            get => _zoom;
+            set
+            {
+                _zoom = value;
+                ApplyZoom();
+            }
+        }
+
+
+        // gets the browser control's underlying activeXcontrol. Ready only from within Loaded-event but before loaded Document!
+        // do not use prior loaded event.
+        public InternetExplorer ActiveXControl
+        {
+            get
+            {
+                // this is a brilliant way to access the WebBrowserObject prior to displaying the actual document (eg. Document property)
+                var fiComWebBrowser =
+                    typeof(WebBrowser).GetField("_axIWebBrowser2", BindingFlags.Instance | BindingFlags.NonPublic);
+                if (fiComWebBrowser == null) return null;
+                var objComWebBrowser = fiComWebBrowser.GetValue(_innerBrowser);
+                return objComWebBrowser as InternetExplorer;
+            }
+        }
+
+        public void Dispose()
+        {
+            _innerBrowser.Source = null;
+            _innerBrowser.Dispose();
+            _innerBrowser = null;
+            Content = null;
+        }
+
+        private void InnerBrowserSizeChanged(object sender, SizeChangedEventArgs e)
+        {
+            ApplyZoom();
+        }
+
+        private void InnerBrowserLoaded(object sender, EventArgs e)
+        {
+            // make browser control not silent: allow HTTP-Auth-dialogs. Requery command availability
+            var ie = ActiveXControl;
+            ie.Silent = true;
+        }
+
+        // called when the loading of a web page is done
+        private void InnerBrowserLoadCompleted(object sender, NavigationEventArgs e)
+        {
+            ApplyZoom(); // apply later and not only at changed event, since only works if browser is rendered.
+        }
+
+        // called when the browser started to load and retrieve data.
+        private void InnerBrowserNavigating(object sender, NavigatingCancelEventArgs e)
+        {
+            if (_loaded)
+                e.Cancel = true;
+            _loaded = true;
+        }
+
+        // re query the commands once done navigating.
+        private void InnerBrowserNavigated(object sender, NavigationEventArgs e)
+        {
+            RegisterWindowErrorHanlder_();
+        }
+
+        public void Navigate(string uri)
+        {
+            Url = uri;
+
+            if (_innerBrowser == null)
+                return;
+
+            if (!string.IsNullOrWhiteSpace(uri) && Uri.IsWellFormedUriString(uri, UriKind.Absolute))
+                try
+                {
+                    _innerBrowser.Source = new Uri(uri);
+                }
+                catch (UriFormatException)
+                {
+                    // just don't crash because of a malformed url
+                }
+            else
+                _innerBrowser.Source = null;
+        }
+
+        public void Navigate(Stream stream)
+        {
+            if (_innerBrowser == null)
+                return;
+
+            try
+            {
+                _innerBrowser.NavigateToStream(stream);
+            }
+            catch (Exception)
+            {
+                // ignored
+            }
+        }
+
+        // register script errors handler on DOM - document.window
+        private void RegisterWindowErrorHanlder_()
+        {
+            object parwin = ((dynamic) _innerBrowser.Document).parentWindow;
+            var cookie = new AxHost.ConnectionPointCookie(parwin, new HtmlWindowEvents2Impl(this),
+                typeof(IIntHTMLWindowEvents2));
+            // MemoryLEAK? No: cookie has a Finalize() to Disconnect istelf. We'll rely on that. If disconnected too early, 
+            // though (eg. in LoadCompleted-event) scripts continue to run and can cause error messages to appear again.
+            // --> forget cookie and be happy.
+        }
+
+        private void ApplyZoom()
+        {
+            if (_innerBrowser == null || !_innerBrowser.IsLoaded)
+                return;
+
+            // grab a handle to the underlying ActiveX object
+            IServiceProvider serviceProvider = null;
+            if (_innerBrowser.Document != null)
+                serviceProvider = (IServiceProvider) _innerBrowser.Document;
+            if (serviceProvider == null)
+                return;
+
+            var serviceGuid = SidSWebBrowserApp;
+            var iid = typeof(IWebBrowser2).GUID;
+            var browserInst =
+                (IWebBrowser2) serviceProvider.QueryService(ref serviceGuid, ref iid);
+
+            try
+            {
+                object zoomPercObj = _zoom;
+                // send the zoom command to the ActiveX object
+                browserInst.ExecWB(OLECMDID.OLECMDID_OPTICAL_ZOOM,
+                    OLECMDEXECOPT.OLECMDEXECOPT_DONTPROMPTUSER,
+                    ref zoomPercObj,
+                    IntPtr.Zero);
+            }
+            catch (Exception)
+            {
+                // ignore this dynamic call if it fails.
+            }
+        }
+
+        // needed to implement the Event for script errors
+        [Guid("3050f625-98b5-11cf-bb82-00aa00bdce0b")]
+        [InterfaceType(ComInterfaceType.InterfaceIsIDispatch)]
+        [TypeLibType(TypeLibTypeFlags.FHidden)]
+        [ComImport]
+        private interface IIntHTMLWindowEvents2
+        {
+            [DispId(1002)]
+            bool onerror(string description, string url, int line);
+        }
+
+        // needed to implement the Event for script errors
+        private class HtmlWindowEvents2Impl : IIntHTMLWindowEvents2
+        {
+            private readonly WpfWebBrowserWrapper _control;
+
+            public HtmlWindowEvents2Impl(WpfWebBrowserWrapper control)
+            {
+                _control = control;
+            }
+
+            // implementation of the onerror Javascript error. Return true to indicate a "Handled" state.
+            public bool onerror(string description, string urlString, int line)
+            {
+                Debug.WriteLine(description + "@" + urlString + ": " + line);
+                // Handled:
+                return true;
+            }
+        }
+
+        // Needed to expose the WebBrowser's underlying ActiveX control for zoom functionality
+        [ComImport]
+        [InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
+        [Guid("6d5140c1-7436-11ce-8034-00aa006009fa")]
+        internal interface IServiceProvider
+        {
+            [return: MarshalAs(UnmanagedType.IUnknown)]
+            object QueryService(ref Guid guidService, ref Guid riid);
+        }
+    }
+}

QuickLook.Plugin/QuickLook.Plugin.MarkdownViewer/Plugin.cs

@@ -1,16 +1,17 @@
 using System;
 using System.IO;
 using System.Windows;
+using System.Windows.Threading;
 using QuickLook.Plugin.HtmlViewer;
 
 namespace QuickLook.Plugin.MarkdownViewer
 {
     public class Plugin : IViewer
     {
-        private WebkitPanel _panel;
+        private WebpagePanel _panel;
 
         public int Priority => int.MaxValue;
-        public bool AllowsTransparency => true;
+        public bool AllowsTransparency => false;
 
         public bool CanHandle(string path)
         {
@@ -20,6 +21,7 @@ namespace QuickLook.Plugin.MarkdownViewer
             switch (Path.GetExtension(path).ToLower())
             {
                 case ".md":
+                case ".rmd":
                     return true;
 
                 default:
@@ -36,13 +38,12 @@ namespace QuickLook.Plugin.MarkdownViewer
 
         public void View(string path, ContextObject context)
         {
-            _panel = new WebkitPanel();
+            _panel = new WebpagePanel();
             context.ViewerContent = _panel;
             context.Title = Path.GetFileName(path);
 
-            _panel.LoadHtml(GenerateMarkdownHtml(path), path);
-
-            context.IsBusy = false;
+            _panel.LoadHtml(GenerateMarkdownHtml(path));
+            _panel.Dispatcher.Invoke(() => { context.IsBusy = false; }, DispatcherPriority.Loaded);
         }
 
         public void Cleanup()