better and faster window resize; Add "AllowsTransparency" to plugin interface; Use IPreviewHandler for Office files

QuickLook.Installer/QuickLook.Installer.wixproj

@@ -64,14 +64,6 @@
       <RefProjectOutputGroups>Binaries;Content;Satellites</RefProjectOutputGroups>
       <RefTargetDir>INSTALLFOLDER</RefTargetDir>
     </ProjectReference>
-    <ProjectReference Include="..\QuickLook.Plugin\QuickLook.Plugin.OfficeViewer\QuickLook.Plugin.OfficeViewer.csproj">
-      <Name>QuickLook.Plugin.OfficeViewer</Name>
-      <Project>{e37675ea-d957-4495-8655-2609bf86756c}</Project>
-      <Private>True</Private>
-      <DoNotHarvest>True</DoNotHarvest>
-      <RefProjectOutputGroups>Binaries;Content;Satellites</RefProjectOutputGroups>
-      <RefTargetDir>INSTALLFOLDER</RefTargetDir>
-    </ProjectReference>
     <ProjectReference Include="..\QuickLook.Plugin\QuickLook.Plugin.PDFViewer\QuickLook.Plugin.PdfViewer.csproj">
       <Name>QuickLook.Plugin.PdfViewer</Name>
       <Project>{a82ac69c-edf5-4f0d-8cbd-8e5e3c06e64d}</Project>

QuickLook.Plugin/QuickLook.Plugin.ArchiveViewer/Plugin.cs

@@ -1,7 +1,6 @@
 using System;
 using System.IO;
 using System.Windows;
-using SharpCompress.Archives;
 
 namespace QuickLook.Plugin.ArchiveViewer
 {
@@ -10,6 +9,7 @@ namespace QuickLook.Plugin.ArchiveViewer
         private ArchiveInfoPanel _panel;
 
         public int Priority => 0;
+        public bool AllowsTransparency => true;
 
         public bool CanHandle(string path)
         {

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

@@ -9,6 +9,7 @@ namespace QuickLook.Plugin.HtmlViewer
         private WebkitPanel _panel;
 
         public int Priority => int.MaxValue;
+        public bool AllowsTransparency => true;
 
         public bool CanHandle(string path)
         {
@@ -30,7 +31,7 @@ namespace QuickLook.Plugin.HtmlViewer
         {
             context.PreferredSize = new Size(800, 800);
 
-            context.Focusable = true;
+            context.CanFocus = true;
         }
 
         public void View(string path, ContextObject context)

QuickLook.Plugin/QuickLook.Plugin.IPreviewHandlers/IInitializeWithFile.cs

@@ -0,0 +1,12 @@
+using System.Runtime.InteropServices;
+
+namespace QuickLook.Plugin.IPreviewHandlers
+{
+    [ComImport]
+    [InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
+    [Guid("b7d14566-0509-4cce-a71f-0a554233bd9b")]
+    internal interface IInitializeWithFile
+    {
+        void Initialize([MarshalAs(UnmanagedType.LPWStr)] string pszFilePath, uint grfMode);
+    }
+}

QuickLook.Plugin/QuickLook.Plugin.IPreviewHandlers/IPreviewHandler.cs

@@ -0,0 +1,23 @@
+using System;
+using System.Drawing;
+using System.Runtime.InteropServices;
+using System.Windows.Forms;
+
+namespace QuickLook.Plugin.IPreviewHandlers
+{
+    [ComImport]
+    [InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
+    [Guid("8895b1c6-b41f-4c1c-a562-0d564250836f")]
+    internal interface IPreviewHandler
+    {
+        void SetWindow(IntPtr hwnd, ref Rectangle rect);
+        void SetRect(ref Rectangle rect);
+        void DoPreview();
+        void Unload();
+        void SetFocus();
+        void QueryFocus(out IntPtr phwnd);
+
+        [PreserveSig]
+        uint TranslateAccelerator(ref Message pmsg);
+    }
+}

QuickLook.Plugin/QuickLook.Plugin.IPreviewHandlers/PluginInterface.cs

@@ -0,0 +1,77 @@
+using System;
+using System.IO;
+using System.Runtime.InteropServices;
+using System.Windows;
+using System.Windows.Interop;
+
+namespace QuickLook.Plugin.IPreviewHandlers
+{
+    public class PluginInterface : IViewer
+    {
+        private PreviewPanel _panel;
+
+        public int Priority => int.MaxValue;
+        public bool AllowsTransparency => false;
+
+        public bool CanHandle(string path)
+        {
+            if (Directory.Exists(path))
+                return false;
+
+            switch (Path.GetExtension(path).ToLower())
+            {
+                case ".doc":
+                case ".docx":
+                case ".xls":
+                case ".xlsx":
+                case ".xlsm":
+                // Visio Viewer will not quit after preview, which cause serious memory issue
+                //case ".vsd":
+                //case ".vsdx":
+                case ".ppt":
+                case ".pptx":
+                    return true;
+            }
+
+            return false;
+        }
+
+        public void Prepare(string path, ContextObject context)
+        {
+            context.SetPreferredSizeFit(new Size {Width = 800, Height = 800}, 0.8);
+        }
+
+        public void View(string path, ContextObject context)
+        {
+            _panel = new PreviewPanel();
+            context.ViewerContent = _panel;
+            context.Title = Path.GetFileName(path);
+
+            _panel.Loaded += (sender, e) =>
+            {
+                _panel.PreviewFile(path);
+                SetForegroundWindow(new WindowInteropHelper(context.ViewerWindow).Handle);
+            };
+
+            context.IsBusy = false;
+        }
+
+        public void Cleanup()
+        {
+            GC.SuppressFinalize(this);
+
+            _panel?.Dispose();
+            _panel = null;
+        }
+
+
+        [DllImport("user32.dll")]
+        [return: MarshalAs(UnmanagedType.Bool)]
+        private static extern bool SetForegroundWindow(IntPtr hWnd);
+
+        ~PluginInterface()
+        {
+            Cleanup();
+        }
+    }
+}

QuickLook.Plugin/QuickLook.Plugin.IPreviewHandlers/PreviewHandlerHost.cs

@@ -0,0 +1,157 @@
+// Preview Handlers Revisted
+// Bradley Smith - 2010/09/17, updated 2013/10/14
+
+using System;
+using System.ComponentModel;
+using System.Drawing;
+using System.IO;
+using System.Runtime.InteropServices;
+using System.Windows.Forms;
+using Microsoft.Win32;
+
+namespace QuickLook.Plugin.IPreviewHandlers
+{
+    /// <summary>
+    ///     A Windows Forms host for Preview Handlers.
+    /// </summary>
+    public class PreviewHandlerHost : Control
+    {
+        /// <summary>
+        ///     The GUID for the IShellItem interface.
+        /// </summary>
+        internal const string GuidIshellitem = "43826d1e-e718-42ee-bc55-a1e261c37bfe";
+
+        private IPreviewHandler _mCurrentPreviewHandler;
+
+        /// <summary>
+        ///     Initialialises a new instance of the PreviewHandlerHost class.
+        /// </summary>
+        public PreviewHandlerHost()
+        {
+            Size = new Size(320, 240);
+        }
+
+        /// <summary>
+        ///     Gets the GUID of the current preview handler.
+        /// </summary>
+        [Browsable(false)]
+        [ReadOnly(true)]
+        public Guid CurrentPreviewHandler { get; private set; } = Guid.Empty;
+
+        /// <summary>
+        ///     Releases the unmanaged resources used by the PreviewHandlerHost and optionally releases the managed resources.
+        /// </summary>
+        /// <param name="disposing"></param>
+        protected override void Dispose(bool disposing)
+        {
+            UnloadPreviewHandler();
+
+            if (_mCurrentPreviewHandler != null)
+            {
+                Marshal.FinalReleaseComObject(_mCurrentPreviewHandler);
+                _mCurrentPreviewHandler = null;
+                GC.Collect();
+            }
+
+            base.Dispose(disposing);
+        }
+
+        /// <summary>
+        ///     Returns the GUID of the preview handler associated with the specified file.
+        /// </summary>
+        /// <param name="filename"></param>
+        /// <returns></returns>
+        private Guid GetPreviewHandlerGUID(string filename)
+        {
+            // open the registry key corresponding to the file extension
+            var ext = Registry.ClassesRoot.OpenSubKey(Path.GetExtension(filename));
+            if (ext != null)
+            {
+                // open the key that indicates the GUID of the preview handler type
+                var test = ext.OpenSubKey("shellex\\{8895b1c6-b41f-4c1c-a562-0d564250836f}");
+                if (test != null) return new Guid(Convert.ToString(test.GetValue(null)));
+
+                // sometimes preview handlers are declared on key for the class
+                var className = Convert.ToString(ext.GetValue(null));
+                if (className != null)
+                {
+                    test = Registry.ClassesRoot.OpenSubKey(
+                        className + "\\shellex\\{8895b1c6-b41f-4c1c-a562-0d564250836f}");
+                    if (test != null) return new Guid(Convert.ToString(test.GetValue(null)));
+                }
+            }
+
+            return Guid.Empty;
+        }
+
+        /// <summary>
+        ///     Resizes the hosted preview handler when this PreviewHandlerHost is resized.
+        /// </summary>
+        /// <param name="e"></param>
+        protected override void OnResize(EventArgs e)
+        {
+            base.OnResize(e);
+
+            var r = ClientRectangle;
+            _mCurrentPreviewHandler?.SetRect(ref r);
+        }
+
+        /// <summary>
+        ///     Opens the specified file using the appropriate preview handler and displays the result in this PreviewHandlerHost.
+        /// </summary>
+        /// <param name="path"></param>
+        /// <returns></returns>
+        public bool Open(string path)
+        {
+            UnloadPreviewHandler();
+
+            if (string.IsNullOrEmpty(path))
+                return false;
+
+            // try to get GUID for the preview handler
+            var guid = GetPreviewHandlerGUID(path);
+
+            if (guid == Guid.Empty)
+                return false;
+
+            CurrentPreviewHandler = guid;
+            var o = Activator.CreateInstance(Type.GetTypeFromCLSID(CurrentPreviewHandler, true));
+
+            var fileInit = o as IInitializeWithFile;
+
+            if (fileInit == null)
+                return false;
+
+            fileInit.Initialize(path, 0);
+            _mCurrentPreviewHandler = o as IPreviewHandler;
+            if (_mCurrentPreviewHandler == null)
+                return false;
+
+            // bind the preview handler to the control's bounds and preview the content
+            var r = ClientRectangle;
+            _mCurrentPreviewHandler.SetWindow(Handle, ref r);
+            _mCurrentPreviewHandler.DoPreview();
+
+            return true;
+        }
+
+        /// <summary>
+        ///     Unloads the preview handler hosted in this PreviewHandlerHost and closes the file stream.
+        /// </summary>
+        public void UnloadPreviewHandler()
+        {
+            try
+            {
+                _mCurrentPreviewHandler?.Unload();
+            }
+            catch (Exception)
+            {
+                // ignored
+            }
+        }
+    }
+
+    #region COM Interop
+
+    #endregion
+}

QuickLook.Plugin/QuickLook.Plugin.IPreviewHandlers/PreviewPanel.xaml

@@ -0,0 +1,12 @@
+<UserControl x:Class="QuickLook.Plugin.IPreviewHandlers.PreviewPanel"
+             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"
+             mc:Ignorable="d"
+             x:Name="panel"
+             d:DesignHeight="300" d:DesignWidth="300">
+    <Grid>
+        <WindowsFormsHost x:Name="presenter" />
+    </Grid>
+</UserControl>

QuickLook.Plugin/QuickLook.Plugin.IPreviewHandlers/PreviewPanel.xaml.cs

@@ -0,0 +1,43 @@
+using System;
+using System.Runtime.InteropServices;
+using System.Windows.Controls;
+
+namespace QuickLook.Plugin.IPreviewHandlers
+{
+    /// <summary>
+    ///     Interaction logic for PreviewPanel.xaml
+    /// </summary>
+    public partial class PreviewPanel : UserControl, IDisposable
+    {
+        private PreviewHandlerHost _control = new PreviewHandlerHost();
+
+        public PreviewPanel()
+        {
+            InitializeComponent();
+        }
+
+        public void Dispose()
+        {
+            presenter.Child = null;
+            presenter?.Dispose();
+
+            _control?.Dispose();
+            _control = null;
+        }
+
+        public void PreviewFile(string file)
+        {
+            _control = new PreviewHandlerHost();
+
+            presenter.Child = _control;
+
+            _control.Open(file);
+
+            SetActiveWindow(presenter.Handle);
+        }
+
+        [DllImport("user32.dll")]
+        [return: MarshalAs(UnmanagedType.Bool)]
+        private static extern bool SetActiveWindow(IntPtr hWnd);
+    }
+}

QuickLook.Plugin/QuickLook.Plugin.IPreviewHandlers/Properties/AssemblyInfo.cs

@@ -5,11 +5,11 @@ using System.Windows;
 // General Information about an assembly is controlled through the following
 // set of attributes. Change these attribute values to modify the information
 // associated with an assembly.
-[assembly: AssemblyTitle("QuickLook.Plugin.OfficeViewer")]
+[assembly: AssemblyTitle("QuickLook.Plugin.IPreviewHandlers")]
 [assembly: AssemblyDescription("")]
 [assembly: AssemblyConfiguration("")]
 [assembly: AssemblyCompany("")]
-[assembly: AssemblyProduct("QuickLook.Plugin.OfficeViewer")]
+[assembly: AssemblyProduct("QuickLook.Plugin.IPreviewHandlers")]
 [assembly: AssemblyCopyright("Copyright ©  2017")]
 [assembly: AssemblyTrademark("")]
 [assembly: AssemblyCulture("")]

QuickLook.Plugin/QuickLook.Plugin.IPreviewHandlers/Properties/Resources.Designer.cs

@@ -8,7 +8,8 @@
 // </auto-generated>
 //------------------------------------------------------------------------------
 
-namespace QuickLook.Plugin.OfficeViewer.Properties {
+namespace QuickLook.Plugin.IPreviewHandlers.Properties {
+    using System;
     
     
     /// <summary>
@@ -37,8 +38,8 @@ namespace QuickLook.Plugin.OfficeViewer.Properties {
         [global::System.ComponentModel.EditorBrowsableAttribute(global::System.ComponentModel.EditorBrowsableState.Advanced)]
         internal static global::System.Resources.ResourceManager ResourceManager {
             get {
-                if ((resourceMan == null)) {
+                if (object.ReferenceEquals(resourceMan, null)) {
-                    global::System.Resources.ResourceManager temp = new global::System.Resources.ResourceManager("QuickLook.Plugin.OfficeViewer.Properties.Resources", typeof(Resources).Assembly);
+                    global::System.Resources.ResourceManager temp = new global::System.Resources.ResourceManager("QuickLook.Plugin.IPreviewHandlers.Properties.Resources", typeof(Resources).Assembly);
                     resourceMan = temp;
                 }
                 return resourceMan;

QuickLook.Plugin/QuickLook.Plugin.IPreviewHandlers/Properties/Settings.Designer.cs

@@ -8,7 +8,7 @@
 // </auto-generated>
 //------------------------------------------------------------------------------
 
-namespace QuickLook.Plugin.OfficeViewer.Properties {
+namespace QuickLook.Plugin.IPreviewHandlers.Properties {
     
     
     [global::System.Runtime.CompilerServices.CompilerGeneratedAttribute()]

QuickLook.Plugin/QuickLook.Plugin.IPreviewHandlers/QuickLook.Plugin.IPreviewHandlers.csproj

@@ -6,8 +6,8 @@
     <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
     <ProjectGuid>{E37675EA-D957-4495-8655-2609BF86756C}</ProjectGuid>
     <OutputType>library</OutputType>
-    <RootNamespace>QuickLook.Plugin.OfficeViewer</RootNamespace>
+    <RootNamespace>QuickLook.Plugin.IPreviewHandlers</RootNamespace>
-    <AssemblyName>QuickLook.Plugin.OfficeViewer</AssemblyName>
+    <AssemblyName>QuickLook.Plugin.IPreviewHandlers</AssemblyName>
     <TargetFrameworkVersion>v4.5.2</TargetFrameworkVersion>
     <FileAlignment>512</FileAlignment>
     <ProjectTypeGuids>{60dc8134-eba5-43b8-bcc9-bb4bc16c2548};{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}</ProjectTypeGuids>
@@ -15,7 +15,7 @@
   </PropertyGroup>
   <PropertyGroup Condition="'$(Configuration)|$(Platform)' == 'Debug|x86'">
     <DebugSymbols>true</DebugSymbols>
-    <OutputPath>..\..\Build\Debug\QuickLook.Plugin\QuickLook.Plugin.OfficeViewer\</OutputPath>
+    <OutputPath>..\..\Build\Debug\QuickLook.Plugin\QuickLook.Plugin.IPreviewHandlers\</OutputPath>
     <DefineConstants>DEBUG;TRACE</DefineConstants>
     <DebugType>full</DebugType>
     <PlatformTarget>x86</PlatformTarget>
@@ -23,7 +23,7 @@
     <CodeAnalysisRuleSet>MinimumRecommendedRules.ruleset</CodeAnalysisRuleSet>
   </PropertyGroup>
   <PropertyGroup Condition="'$(Configuration)|$(Platform)' == 'Release|x86'">
-    <OutputPath>..\..\Build\Release\QuickLook.Plugin\QuickLook.Plugin.OfficeViewer\</OutputPath>
+    <OutputPath>..\..\Build\Release\QuickLook.Plugin\QuickLook.Plugin.IPreviewHandlers\</OutputPath>
     <DefineConstants>TRACE</DefineConstants>
     <Optimize>true</Optimize>
     <DebugType>pdbonly</DebugType>
@@ -32,44 +32,35 @@
     <CodeAnalysisRuleSet>MinimumRecommendedRules.ruleset</CodeAnalysisRuleSet>
   </PropertyGroup>
   <ItemGroup>
-    <Reference Include="Microsoft.Office.Interop.Excel, Version=15.0.0.0, Culture=neutral, PublicKeyToken=71e9bce111e9429c, processorArchitecture=MSIL">
-      <EmbedInteropTypes>True</EmbedInteropTypes>
-      <HintPath>..\..\packages\Microsoft.Office.Interop.Excel.15.0.4795.1000\lib\net20\Microsoft.Office.Interop.Excel.dll</HintPath>
-      <Private>True</Private>
-    </Reference>
-    <Reference Include="Microsoft.Office.Interop.PowerPoint, Version=15.0.0.0, Culture=neutral, PublicKeyToken=71e9bce111e9429c, processorArchitecture=MSIL">
-      <EmbedInteropTypes>True</EmbedInteropTypes>
-      <HintPath>..\..\packages\Microsoft.Office.Interop.PowerPoint.15.0.4420.1017\lib\net20\Microsoft.Office.Interop.PowerPoint.dll</HintPath>
-      <Private>True</Private>
-    </Reference>
-    <Reference Include="Microsoft.Office.Interop.Word, Version=15.0.0.0, Culture=neutral, PublicKeyToken=71e9bce111e9429c, processorArchitecture=MSIL">
-      <EmbedInteropTypes>True</EmbedInteropTypes>
-      <HintPath>..\..\packages\Microsoft.Office.Interop.Word.15.0.4797.1003\lib\net20\Microsoft.Office.Interop.Word.dll</HintPath>
-      <Private>True</Private>
-    </Reference>
-    <Reference Include="office, Version=15.0.0.0, Culture=neutral, PublicKeyToken=71e9bce111e9429c">
-      <EmbedInteropTypes>True</EmbedInteropTypes>
-    </Reference>
     <Reference Include="System" />
-    <Reference Include="Microsoft.CSharp" />
     <Reference Include="System.Core" />
+    <Reference Include="System.Drawing" />
+    <Reference Include="System.Windows.Forms" />
     <Reference Include="System.Xaml">
       <RequiredTargetFramework>4.0</RequiredTargetFramework>
     </Reference>
     <Reference Include="WindowsBase" />
     <Reference Include="PresentationCore" />
     <Reference Include="PresentationFramework" />
+    <Reference Include="WindowsFormsIntegration" />
   </ItemGroup>
   <ItemGroup>
     <Compile Include="..\..\GitVersion.cs">
       <Link>Properties\GitVersion.cs</Link>
     </Compile>
-    <Compile Include="OfficeInteropWrapper.cs" />
+    <Compile Include="IInitializeWithFile.cs" />
+    <Compile Include="IPreviewHandler.cs" />
     <Compile Include="PluginInterface.cs">
       <SubType>Code</SubType>
     </Compile>
   </ItemGroup>
   <ItemGroup>
+    <Compile Include="PreviewHandlerHost.cs">
+      <SubType>Component</SubType>
+    </Compile>
+    <Compile Include="PreviewPanel.xaml.cs">
+      <DependentUpon>PreviewPanel.xaml</DependentUpon>
+    </Compile>
     <Compile Include="Properties\AssemblyInfo.cs">
       <SubType>Code</SubType>
     </Compile>
@@ -87,7 +78,6 @@
       <Generator>ResXFileCodeGenerator</Generator>
       <LastGenOutput>Resources.Designer.cs</LastGenOutput>
     </EmbeddedResource>
-    <None Include="packages.config" />
     <None Include="Properties\Settings.settings">
       <Generator>SettingsSingleFileGenerator</Generator>
       <LastGenOutput>Settings.Designer.cs</LastGenOutput>
@@ -99,11 +89,12 @@
       <Name>QuickLook</Name>
       <Private>False</Private>
     </ProjectReference>
-    <ProjectReference Include="..\QuickLook.Plugin.PDFViewer\QuickLook.Plugin.PdfViewer.csproj">
+  </ItemGroup>
-      <Project>{a82ac69c-edf5-4f0d-8cbd-8e5e3c06e64d}</Project>
+  <ItemGroup>
-      <Name>QuickLook.Plugin.PdfViewer</Name>
+    <Page Include="PreviewPanel.xaml">
-      <Private>False</Private>
+      <SubType>Designer</SubType>
-    </ProjectReference>
+      <Generator>MSBuild:Compile</Generator>
+    </Page>
   </ItemGroup>
   <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
 </Project>

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

@@ -8,7 +8,8 @@ namespace QuickLook.Plugin.ImageViewer
         private Size _imageSize;
         private ImagePanel _ip;
 
-        public int Priority => 9999;
+        public int Priority => int.MaxValue;
+        public bool AllowsTransparency => true;
 
         public bool CanHandle(string path)
         {

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

@@ -10,6 +10,7 @@ namespace QuickLook.Plugin.MarkdownViewer
         private WebkitPanel _panel;
 
         public int Priority => int.MaxValue;
+        public bool AllowsTransparency => true;
 
         public bool CanHandle(string path)
         {
@@ -30,7 +31,7 @@ namespace QuickLook.Plugin.MarkdownViewer
         {
             context.PreferredSize = new Size(800, 800);
 
-            context.Focusable = true;
+            context.CanFocus = true;
         }
 
         public void View(string path, ContextObject context)

QuickLook.Plugin/QuickLook.Plugin.OfficeViewer/OfficeInteropWrapper.cs

@@ -1,189 +0,0 @@
-using System;
-using System.Diagnostics;
-using System.IO;
-using Microsoft.Office.Interop.Excel;
-using Microsoft.Office.Interop.PowerPoint;
-using Microsoft.Office.Interop.Word;
-using Application = Microsoft.Office.Interop.Excel.Application;
-using Task = System.Threading.Tasks.Task;
-
-namespace QuickLook.Plugin.OfficeViewer
-{
-    internal class OfficeInteropWrapper : IDisposable
-    {
-        public enum FileTypeEnum
-        {
-            Word,
-            Excel,
-            PowerPoint
-        }
-
-        private readonly string _path;
-        private readonly string _tempPdf = Path.GetTempFileName();
-
-        private Application _excelApp;
-        private Microsoft.Office.Interop.PowerPoint.Application _powerpointApp;
-        private Microsoft.Office.Interop.Word.Application _wordApp;
-
-        public OfficeInteropWrapper(string path)
-        {
-            _path = path;
-
-            switch (Path.GetExtension(path).ToLower())
-            {
-                case ".doc":
-                case ".docx":
-                    FileType = FileTypeEnum.Word;
-                    break;
-                case ".xls":
-                case ".xlsx":
-                case ".xlsm":
-                    FileType = FileTypeEnum.Excel;
-                    break;
-                case ".ppt":
-                case ".pptx":
-                    FileType = FileTypeEnum.PowerPoint;
-                    break;
-                default:
-                    throw new NotSupportedException($"{path} is not supported.");
-            }
-
-            LoadApplication();
-        }
-
-        public FileTypeEnum FileType { get; }
-
-        public void Dispose()
-        {
-            GC.SuppressFinalize(this);
-
-            // communicate with COM in a separate thread
-            Task.Run(() =>
-                {
-                    try
-                    {
-                        //_wordApp?.Documents.Close(false);
-                        _wordApp?.Quit(false);
-                        _wordApp = null;
-
-                        _excelApp?.Workbooks.Close();
-                        _excelApp?.Quit();
-                        _excelApp = null;
-
-                        _powerpointApp?.Quit();
-                        _powerpointApp = null;
-                    }
-                    catch (Exception e)
-                    {
-                        Debug.WriteLine(e.Message);
-                        Debug.WriteLine(e.StackTrace);
-                    }
-                })
-                .Wait();
-        }
-
-        public string SaveAsPdf()
-        {
-            if (_wordApp == null && _excelApp == null && _powerpointApp == null)
-                throw new Exception("Office application launch failed.");
-
-            var succeeded = false;
-
-            // communicate with COM in a separate thread
-            Task.Run(() =>
-                {
-                    try
-                    {
-                        switch (FileType)
-                        {
-                            case FileTypeEnum.Word:
-                                _wordApp.ActiveDocument.ExportAsFixedFormat(_tempPdf,
-                                    WdExportFormat.wdExportFormatPDF);
-                                succeeded = true;
-                                break;
-                            case FileTypeEnum.Excel:
-                                _excelApp.ActiveWorkbook.ExportAsFixedFormat(XlFixedFormatType.xlTypePDF,
-                                    _tempPdf);
-                                succeeded = true;
-                                break;
-                            case FileTypeEnum.PowerPoint:
-                                _powerpointApp.ActivePresentation.ExportAsFixedFormat(_tempPdf,
-                                    PpFixedFormatType.ppFixedFormatTypePDF);
-                                succeeded = true;
-                                break;
-                            default:
-                                throw new NotSupportedException($"{_path} is not supported.");
-                        }
-                    }
-                    catch (Exception e)
-                    {
-                        Debug.WriteLine(e.Message);
-                        Debug.WriteLine(e.StackTrace);
-                    }
-                })
-                .Wait();
-
-            if (succeeded)
-                return FileType == FileTypeEnum.Excel
-                    ? _tempPdf + ".pdf"
-                    : _tempPdf; // Excel will add ".pdf" to our filename
-
-            Dispose();
-            return string.Empty;
-        }
-
-        private void LoadApplication()
-        {
-            var succeeded = false;
-
-            // communicate with COM in a separate thread
-            Task.Run(() =>
-                {
-                    try
-                    {
-                        switch (FileType)
-                        {
-                            case FileTypeEnum.Word:
-                                _wordApp = new Microsoft.Office.Interop.Word.Application();
-                                _wordApp.DisplayAlerts = WdAlertLevel.wdAlertsNone;
-                                _wordApp.Documents.Open(_path);
-                                succeeded = true;
-                                break;
-                            case FileTypeEnum.Excel:
-                                _excelApp = new Application();
-                                _excelApp.DisplayAlerts = false;
-                                _excelApp.Workbooks.Open(_path);
-                                var worksheets = _excelApp.ActiveWorkbook.Sheets;
-                                if (worksheets != null)
-                                    foreach (Worksheet sheet in worksheets)
-                                        sheet.PageSetup.PrintGridlines = true;
-                                succeeded = true;
-                                break;
-                            case FileTypeEnum.PowerPoint:
-                                _powerpointApp = new Microsoft.Office.Interop.PowerPoint.Application();
-                                _powerpointApp.DisplayAlerts = PpAlertLevel.ppAlertsNone;
-                                _powerpointApp.Presentations.Open(_path);
-                                succeeded = true;
-                                break;
-                            default:
-                                throw new NotSupportedException($"{_path} is not supported.");
-                        }
-                    }
-                    catch (Exception e)
-                    {
-                        Debug.WriteLine(e.Message);
-                        Debug.WriteLine(e.StackTrace);
-                    }
-                })
-                .Wait();
-
-            if (!succeeded)
-                Dispose();
-        }
-
-        ~OfficeInteropWrapper()
-        {
-            Dispose();
-        }
-    }
-}

QuickLook.Plugin/QuickLook.Plugin.OfficeViewer/PluginInterface.cs

@@ -1,96 +0,0 @@
-using System;
-using System.IO;
-using System.Windows;
-using QuickLook.Plugin.PDFViewer;
-
-namespace QuickLook.Plugin.OfficeViewer
-{
-    public class PluginInterface : IViewer
-    {
-        private string _pdfPath = "";
-        private PdfViewerControl _pdfViewer;
-
-        public int Priority => int.MaxValue;
-
-        public bool CanHandle(string path)
-        {
-            if (Directory.Exists(path))
-                return false;
-
-            switch (Path.GetExtension(path).ToLower())
-            {
-                case ".doc":
-                case ".docx":
-                case ".xls":
-                case ".xlsx":
-                case ".xlsm":
-                case ".ppt":
-                case ".pptx":
-                    return true;
-            }
-
-            return false;
-        }
-
-        public void Prepare(string path, ContextObject context)
-        {
-            context.SetPreferredSizeFit(new Size {Width = 800, Height = 600}, 0.8);
-        }
-
-        public void View(string path, ContextObject context)
-        {
-            using (var officeApp = new OfficeInteropWrapper(path))
-            {
-                _pdfPath = officeApp.SaveAsPdf();
-            }
-
-            if (string.IsNullOrEmpty(_pdfPath))
-                throw new Exception("COM failed.");
-
-            _pdfViewer = new PdfViewerControl();
-
-            _pdfViewer.Loaded += (sender, e) =>
-            {
-                try
-                {
-                    _pdfViewer.LoadPdf(_pdfPath);
-                }
-                catch (Exception ex)
-                {
-                    throw ex;
-                }
-
-                context.Title = $"{Path.GetFileName(path)} (1 / {_pdfViewer.TotalPages})";
-            };
-            _pdfViewer.CurrentPageChanged += (sender, e) => context.Title =
-                $"{Path.GetFileName(path)} ({_pdfViewer.CurrentPage + 1} / {_pdfViewer.TotalPages})";
-
-            context.ViewerContent = _pdfViewer;
-
-            context.IsBusy = false;
-        }
-
-        public void Cleanup()
-        {
-            GC.SuppressFinalize(this);
-
-            // release the Pdf file first
-            _pdfViewer?.Dispose();
-            _pdfViewer = null;
-
-            try
-            {
-                File.Delete(_pdfPath);
-            }
-            catch (Exception)
-            {
-                // ignored
-            }
-        }
-
-        ~PluginInterface()
-        {
-            Cleanup();
-        }
-    }
-}

QuickLook.Plugin/QuickLook.Plugin.OfficeViewer/packages.config

@@ -1,7 +0,0 @@
-<?xml version="1.0" encoding="utf-8"?>
-
-<packages>
-  <package id="Microsoft.Office.Interop.Excel" version="15.0.4795.1000" targetFramework="net452" />
-  <package id="Microsoft.Office.Interop.PowerPoint" version="15.0.4420.1017" targetFramework="net452" />
-  <package id="Microsoft.Office.Interop.Word" version="15.0.4797.1003" targetFramework="net452" />
-</packages>

QuickLook.Plugin/QuickLook.Plugin.PDFViewer/Plugin.cs

@@ -9,6 +9,7 @@ namespace QuickLook.Plugin.PDFViewer
         private PdfViewerControl _pdfControl;
 
         public int Priority => int.MaxValue;
+        public bool AllowsTransparency => true;
 
         public bool CanHandle(string path)
         {

QuickLook.Plugin/QuickLook.Plugin.TextViewer/Plugin.cs

@@ -9,6 +9,7 @@ namespace QuickLook.Plugin.TextViewer
         private TextViewerPanel _tvp;
 
         public int Priority => 0;
+        public bool AllowsTransparency => true;
 
         public bool CanHandle(string path)
         {
@@ -43,7 +44,7 @@ namespace QuickLook.Plugin.TextViewer
         public void Prepare(string path, ContextObject context)
         {
             context.PreferredSize = new Size {Width = 800, Height = 600};
-            context.Focusable = true;
+            context.CanFocus = true;
         }
 
         public void View(string path, ContextObject context)

QuickLook.Plugin/QuickLook.Plugin.VideoViewer/PluginInterface.cs

@@ -11,6 +11,7 @@ namespace QuickLook.Plugin.VideoViewer
         private ViewerPanel _vp;
 
         public int Priority => int.MaxValue;
+        public bool AllowsTransparency => true;
 
         public bool CanHandle(string path)
         {

QuickLook.sln

@@ -20,8 +20,6 @@ Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "QuickLook.Plugin.PdfViewer"
 EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "QuickLook.Plugin.TextViewer", "QuickLook.Plugin\QuickLook.Plugin.TextViewer\QuickLook.Plugin.TextViewer.csproj", "{AE041682-E3A1-44F6-8BB4-916A98D89FBE}"
 EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "QuickLook.Plugin.OfficeViewer", "QuickLook.Plugin\QuickLook.Plugin.OfficeViewer\QuickLook.Plugin.OfficeViewer.csproj", "{E37675EA-D957-4495-8655-2609BF86756C}"
-EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "QuickLook.Plugin.VideoViewer", "QuickLook.Plugin\QuickLook.Plugin.VideoViewer\QuickLook.Plugin.VideoViewer.csproj", "{1B746D92-49A5-4A37-9D75-DCC490393290}"
 EndProject
 Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "Solution Items", "Solution Items", "{BAE81497-98FA-4A7A-A0FB-2B86C9694B9C}"
@@ -35,6 +33,8 @@ Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "QuickLook.Plugin.MarkdownVi
 EndProject
 Project("{930C7802-8A8C-48F9-8165-68863BCCD9DD}") = "QuickLook.Installer", "QuickLook.Installer\QuickLook.Installer.wixproj", "{F0214FC2-EFBE-426C-842D-B42BC37D9525}"
 EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "QuickLook.Plugin.IPreviewHandlers", "QuickLook.Plugin\QuickLook.Plugin.IPreviewHandlers\QuickLook.Plugin.IPreviewHandlers.csproj", "{E37675EA-D957-4495-8655-2609BF86756C}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -79,12 +79,6 @@ Global
 		{AE041682-E3A1-44F6-8BB4-916A98D89FBE}.Release|Any CPU.ActiveCfg = Release|x86
 		{AE041682-E3A1-44F6-8BB4-916A98D89FBE}.Release|x86.ActiveCfg = Release|x86
 		{AE041682-E3A1-44F6-8BB4-916A98D89FBE}.Release|x86.Build.0 = Release|x86
-		{E37675EA-D957-4495-8655-2609BF86756C}.Debug|Any CPU.ActiveCfg = Debug|x86
-		{E37675EA-D957-4495-8655-2609BF86756C}.Debug|x86.ActiveCfg = Debug|x86
-		{E37675EA-D957-4495-8655-2609BF86756C}.Debug|x86.Build.0 = Debug|x86
-		{E37675EA-D957-4495-8655-2609BF86756C}.Release|Any CPU.ActiveCfg = Release|x86
-		{E37675EA-D957-4495-8655-2609BF86756C}.Release|x86.ActiveCfg = Release|x86
-		{E37675EA-D957-4495-8655-2609BF86756C}.Release|x86.Build.0 = Release|x86
 		{1B746D92-49A5-4A37-9D75-DCC490393290}.Debug|Any CPU.ActiveCfg = Debug|x86
 		{1B746D92-49A5-4A37-9D75-DCC490393290}.Debug|x86.ActiveCfg = Debug|x86
 		{1B746D92-49A5-4A37-9D75-DCC490393290}.Debug|x86.Build.0 = Debug|x86
@@ -108,6 +102,12 @@ Global
 		{F0214FC2-EFBE-426C-842D-B42BC37D9525}.Release|Any CPU.ActiveCfg = Release|x86
 		{F0214FC2-EFBE-426C-842D-B42BC37D9525}.Release|x86.ActiveCfg = Release|x86
 		{F0214FC2-EFBE-426C-842D-B42BC37D9525}.Release|x86.Build.0 = Release|x86
+		{E37675EA-D957-4495-8655-2609BF86756C}.Debug|Any CPU.ActiveCfg = Debug|x86
+		{E37675EA-D957-4495-8655-2609BF86756C}.Debug|x86.ActiveCfg = Debug|x86
+		{E37675EA-D957-4495-8655-2609BF86756C}.Debug|x86.Build.0 = Debug|x86
+		{E37675EA-D957-4495-8655-2609BF86756C}.Release|Any CPU.ActiveCfg = Release|x86
+		{E37675EA-D957-4495-8655-2609BF86756C}.Release|x86.ActiveCfg = Release|x86
+		{E37675EA-D957-4495-8655-2609BF86756C}.Release|x86.Build.0 = Release|x86
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE
@@ -117,9 +117,9 @@ Global
 		{FE5A5111-9607-4721-A7BE-422754002ED8} = {06EFDBE0-6408-4B37-BCF2-0CF9EBEA2E93}
 		{A82AC69C-EDF5-4F0D-8CBD-8E5E3C06E64D} = {06EFDBE0-6408-4B37-BCF2-0CF9EBEA2E93}
 		{AE041682-E3A1-44F6-8BB4-916A98D89FBE} = {06EFDBE0-6408-4B37-BCF2-0CF9EBEA2E93}
-		{E37675EA-D957-4495-8655-2609BF86756C} = {06EFDBE0-6408-4B37-BCF2-0CF9EBEA2E93}
 		{1B746D92-49A5-4A37-9D75-DCC490393290} = {06EFDBE0-6408-4B37-BCF2-0CF9EBEA2E93}
 		{CE22A1F3-7F2C-4EC8-BFDE-B58D0EB625FC} = {06EFDBE0-6408-4B37-BCF2-0CF9EBEA2E93}
 		{AB1270AF-7EB4-4B4F-9E09-6404F1A28EA0} = {06EFDBE0-6408-4B37-BCF2-0CF9EBEA2E93}
+		{E37675EA-D957-4495-8655-2609BF86756C} = {06EFDBE0-6408-4B37-BCF2-0CF9EBEA2E93}
 	EndGlobalSection
 EndGlobal

QuickLook/Converters/BooleanToResizeBorderThicknessConverter.cs

@@ -0,0 +1,25 @@
+using System;
+using System.Globalization;
+using System.Windows;
+using System.Windows.Data;
+
+namespace QuickLook.Converters
+{
+    public sealed class BooleanToResizeBorderThicknessConverter : DependencyObject, IValueConverter
+    {
+        public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
+        {
+            if (value == null)
+                return Visibility.Visible;
+
+            var v = (bool) value;
+
+            return v ? 6 : 0;
+        }
+
+        object IValueConverter.ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
+        {
+            throw new NotImplementedException();
+        }
+    }
+}

QuickLook/Converters/BooleanToVisibilityCollapsedConverter.cs

@@ -0,0 +1,25 @@
+using System;
+using System.Globalization;
+using System.Windows;
+using System.Windows.Data;
+
+namespace QuickLook.Converters
+{
+    public sealed class BooleanToVisibilityCollapsedConverter : DependencyObject, IValueConverter
+    {
+        public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
+        {
+            if (value == null)
+                return Visibility.Visible;
+
+            var v = (bool) value;
+
+            return v ? Visibility.Visible : Visibility.Collapsed;
+        }
+
+        object IValueConverter.ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
+        {
+            throw new NotImplementedException();
+        }
+    }
+}

QuickLook/Helpers/BlurLibrary/BlurWindow.cs

@@ -1,5 +1,6 @@
 using System;
 using System.Windows;
+using System.Windows.Interop;
 
 namespace QuickLook.Helpers.BlurLibrary
 {
@@ -36,7 +37,7 @@ namespace QuickLook.Helpers.BlurLibrary
         /// <param name="window">Window object</param>
         public static void EnableWindowBlur(Window window)
         {
-            EnableWindowBlur(Helpers.GetWindowHandle(window));
+            EnableWindowBlur(new WindowInteropHelper(window).Handle);
         }
 
         private static void DisableWindowBlur(IntPtr hwnd)
@@ -53,7 +54,7 @@ namespace QuickLook.Helpers.BlurLibrary
         /// <param name="window">Window object</param>
         public static void DisableWindowBlur(Window window)
         {
-            DisableWindowBlur(Helpers.GetWindowHandle(window));
+            DisableWindowBlur(new WindowInteropHelper(window).Handle);
         }
     }
 }

QuickLook/MainWindowNoTransparent.cs

@@ -0,0 +1,13 @@
+using System.Windows.Media;
+
+namespace QuickLook
+{
+    internal class MainWindowNoTransparent : MainWindowTransparent
+    {
+        public MainWindowNoTransparent()
+        {
+            Background = new SolidColorBrush(Colors.White);
+            AllowsTransparency = false;
+        }
+    }
+}

QuickLook/MainWindowTransparent.xaml

@@ -6,18 +6,24 @@
     xmlns:control="clr-namespace:QuickLook.Controls"
     xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
     xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
-    mc:Ignorable="d" x:Class="QuickLook.MainWindow" x:Name="mainWindow"
+    xmlns:converters="clr-namespace:QuickLook.Converters"
+    mc:Ignorable="d" x:Class="QuickLook.MainWindowTransparent" x:Name="mainWindow"
     UseLayoutRounding="True"
     d:DesignWidth="624" d:DesignHeight="700"
     MinWidth="275" MinHeight="150"
     WindowStartupLocation="CenterScreen"
-    x:ClassModifier="internal" Focusable="False"
+    Focusable="False" WindowStyle="None"
-    ShowActivated="False" ShowInTaskbar="False" WindowStyle="None"
+    Background="#E5FAFAFA" AllowsTransparency="True"
-    FontFamily="Segoe UI,Microsoft Yahei UI"
+    ShowActivated="False" ShowInTaskbar="False"
-    ResizeMode="CanResizeWithGrip" AllowsTransparency="True">
+    FontFamily="Segoe UI,Microsoft Yahei UI">
-    <Window.Background>
+    <Window.Resources>
-        <SolidColorBrush Color="#E5FAFAFA" />
+        <converters:BooleanToResizeBorderThicknessConverter x:Key="BooleanToResizeBorderThicknessConverter" />
-    </Window.Background>
+    </Window.Resources>
+    <WindowChrome.WindowChrome>
+        <WindowChrome CaptionHeight="{Binding Height, ElementName=titlebar}"
+                      ResizeBorderThickness="{Binding ContextObject.CanResize, Converter={StaticResource BooleanToResizeBorderThicknessConverter}, ElementName=mainWindow}"
+                      UseAeroCaptionButtons="False" />
+    </WindowChrome.WindowChrome>
     <Border x:Name="windowBorder" BorderThickness="1" BorderBrush="#FF7B7B7B">
         <Grid>
             <DockPanel x:Name="windowPanel">
@@ -48,10 +54,11 @@
                 </DockPanel.Style>
                 <DockPanel x:Name="titlebar" Height="28" Dock="Top">
                     <fa:ImageAwesome DockPanel.Dock="Right" x:Name="buttonCloseWindow" Icon="TimesCircle"
+                                     WindowChrome.IsHitTestVisibleInChrome="True"
                                      Height="15" Margin="10,0" Foreground="Gray"
                                      Cursor="Hand" />
                     <!-- set grid.background colour makes it clickable -->
-                    <Grid x:Name="titleBarArea" Background="Transparent">
+                    <Grid x:Name="titleArea" Background="Transparent">
                         <TextBlock Text="{Binding ContextObject.Title, ElementName=mainWindow}" FontSize="14"
                                    HorizontalAlignment="Center"
                                    VerticalAlignment="Center" />

QuickLook/MainWindowTransparent.xaml.cs

@@ -1,9 +1,7 @@
 using System;
 using System.Diagnostics;
 using System.Windows;
-using System.Windows.Input;
 using System.Windows.Threading;
-using QuickLook.ExtensionMethods;
 using QuickLook.Helpers;
 using QuickLook.Helpers.BlurLibrary;
 using QuickLook.Plugin;
@@ -11,11 +9,11 @@ using QuickLook.Plugin;
 namespace QuickLook
 {
     /// <summary>
-    ///     Interaction logic for MainWindow.xaml
+    ///     Interaction logic for MainWindowTransparent.xaml
     /// </summary>
-    internal partial class MainWindow : Window
+    public partial class MainWindowTransparent : Window
     {
-        internal MainWindow()
+        internal MainWindowTransparent()
         {
             // this object should be initialized before loading UI components, because many of which are binding to it.
             ContextObject = new ContextObject();
@@ -26,33 +24,17 @@ namespace QuickLook
             if (!Debugger.IsAttached)
                 Topmost = true;
 
-            Loaded += (sender, e) => BlurWindow.EnableWindowBlur(this);
+            SourceInitialized += (sender, e) =>
+            {
+                if (AllowsTransparency)
+                    BlurWindow.EnableWindowBlur(this);
+            };
 
-            buttonCloseWindow.MouseLeftButtonUp += (sender, e) => { Hide(); };
+            buttonCloseWindow.MouseLeftButtonUp += (sender, e) => Hide();
-
-            titleBarArea.PreviewMouseLeftButtonDown += DragMoveCurrentWindow;
         }
 
         public ContextObject ContextObject { get; private set; }
 
-        private void DragMoveCurrentWindow(object sender, MouseButtonEventArgs e)
-        {
-            if (WindowState == WindowState.Maximized)
-            {
-                var dpi = DpiHelper.GetCurrentDpi();
-
-                // MouseDevice.GetPosition() returns device-dependent coordinate, however WPF is not like that
-                var point = PointToScreen(e.MouseDevice.GetPosition(this));
-
-                Left = point.X / (dpi.HorizontalDpi / DpiHelper.DEFAULT_DPI) - RestoreBounds.Width * 0.5;
-                Top = point.Y / (dpi.VerticalDpi / DpiHelper.DEFAULT_DPI);
-
-                WindowState = WindowState.Normal;
-            }
-
-            DragMove();
-        }
-
         private new void Show()
         {
             // revert UI changes
@@ -65,11 +47,9 @@ namespace QuickLook
 
             ResizeAndCenter(new Size(newWidth, newHeight));
 
-            ResizeMode = ContextObject.CanResize ? ResizeMode.CanResizeWithGrip : ResizeMode.NoResize;
-
             base.Show();
 
-            //if (!ContextObject.Focusable)
+            //if (!ContextObject.CanFocus)
             //    WindowHelper.SetNoactivate(new WindowInteropHelper(this));
         }
 
@@ -125,6 +105,7 @@ namespace QuickLook
         {
             ContextObject.CurrentContentContainer = container;
             ContextObject.ViewerPlugin = matchedPlugin;
+            ContextObject.ViewerWindow = this;
 
             // get window size before showing it
             ContextObject.ViewerPlugin.Prepare(path, ContextObject);

QuickLook/PidHelper.cs

@@ -23,7 +23,9 @@ namespace QuickLook
             var ppid = -1;
             using (var file = File.Open(pid, FileMode.Open, FileAccess.Read, FileShare.ReadWrite))
             using (var sr = new StreamReader(file))
+            {
                 int.TryParse(sr.ReadToEnd(), out ppid);
+            }
 
             try
             {

QuickLook/Plugin/ContextObject.cs

@@ -13,12 +13,19 @@ namespace QuickLook.Plugin
     /// </summary>
     public class ContextObject : INotifyPropertyChanged
     {
-        private bool _isBusy = true;
+        private bool _canFocus;
+        private bool _canResize = true;
 
+        private bool _isBusy = true;
         private string _title = "";
         internal ContentControl CurrentContentContainer;
         internal IViewer ViewerPlugin;
 
+        /// <summary>
+        ///     Get the viewer window.
+        /// </summary>
+        public MainWindowTransparent ViewerWindow { get; internal set; }
+
         /// <summary>
         ///     Get or set the title of Viewer window.
         /// </summary>
@@ -62,12 +69,28 @@ namespace QuickLook.Plugin
         /// <summary>
         ///     Set whether user are allowed to resize the viewer window.
         /// </summary>
-        public bool CanResize { get; set; } = true;
+        public bool CanResize
+        {
+            get => _canResize;
+            set
+            {
+                _canResize = value;
+                OnPropertyChanged();
+            }
+        }
 
         /// <summary>
         ///     Set whether user are allowed to set focus at the viewer window.
         /// </summary>
-        public bool Focusable { get; set; }
+        public bool CanFocus
+        {
+            get => _canFocus;
+            set
+            {
+                _canFocus = value;
+                OnPropertyChanged();
+            }
+        }
 
         public event PropertyChangedEventHandler PropertyChanged;
 
@@ -122,12 +145,13 @@ namespace QuickLook.Plugin
 
         internal void Reset()
         {
+            ViewerWindow = null;
             Title = "";
             ViewerContent = null;
             IsBusy = true;
             PreferredSize = new Size();
             CanResize = true;
-            Focusable = false;
+            CanFocus = false;
         }
 
         [NotifyPropertyChangedInvocator]

QuickLook/Plugin/IViewer.cs

@@ -11,6 +11,11 @@
         /// </summary>
         int Priority { get; }
 
+        /// <summary>
+        ///     Set whether the viewer window has blur effect.
+        /// </summary>
+        bool AllowsTransparency { get; }
+
         /// <summary>
         ///     Determine whether this plugin can open this file. Please also check the file header, if applicable.
         /// </summary>

QuickLook/Plugin/InfoPanel/PluginInterface.cs

@@ -7,6 +7,7 @@ namespace QuickLook.Plugin.InfoPanel
         private InfoPanel _ip;
 
         public int Priority => int.MinValue;
+        public bool AllowsTransparency => true;
 
         public bool CanHandle(string sample)
         {
@@ -16,15 +17,15 @@ namespace QuickLook.Plugin.InfoPanel
         public void Prepare(string path, ContextObject context)
         {
             context.PreferredSize = new Size {Width = 453, Height = 172};
+
+            context.Title = "";
+            context.CanResize = false;
         }
 
         public void View(string path, ContextObject context)
         {
             _ip = new InfoPanel();
-
-            context.Title = "";
             context.ViewerContent = _ip;
-            context.CanResize = false;
 
             _ip.DisplayInfo(path);
 

QuickLook/QuickLook.csproj

@@ -80,6 +80,8 @@
     <Compile Include="..\GitVersion.cs">
       <Link>Properties\GitVersion.cs</Link>
     </Compile>
+    <Compile Include="Converters\BooleanToVisibilityCollapsedConverter.cs" />
+    <Compile Include="Converters\BooleanToResizeBorderThicknessConverter.cs" />
     <Compile Include="Helpers\AutoStartupHelper.cs" />
     <Compile Include="Controls\BackgroundVisualHost.cs" />
     <Compile Include="Controls\BusyDecorator.cs" />
@@ -103,6 +105,7 @@
     <Compile Include="Helpers\BlurLibrary\PlatformsImpl\Windows81WindowBlurController.cs" />
     <Compile Include="Helpers\BlurLibrary\PlatformsImpl\Windows8WindowBlurController.cs" />
     <Compile Include="Helpers\BlurLibrary\PlatformsImpl\WindowsVistaWindowBlurController.cs" />
+    <Compile Include="MainWindowNoTransparent.cs" />
     <Compile Include="NativeMethods\ShellLink.cs" />
     <Compile Include="PidHelper.cs" />
     <Compile Include="PluginManager.cs" />
@@ -128,7 +131,7 @@
       <SubType>Designer</SubType>
       <Generator>MSBuild:Compile</Generator>
     </Page>
-    <Page Include="MainWindow.xaml">
+    <Page Include="MainWindowTransparent.xaml">
       <Generator>MSBuild:Compile</Generator>
       <SubType>Designer</SubType>
     </Page>
@@ -142,8 +145,8 @@
     <Compile Include="NativeMethods\User32.cs" />
     <Compile Include="Properties\Annotations.cs" />
     <Compile Include="GlobalKeyboardHook.cs" />
-    <Compile Include="MainWindow.xaml.cs">
+    <Compile Include="MainWindowTransparent.xaml.cs">
-      <DependentUpon>MainWindow.xaml</DependentUpon>
+      <DependentUpon>MainWindowTransparent.xaml</DependentUpon>
       <SubType>Code</SubType>
     </Compile>
     <Page Include="Styles\BusyDecorator.xaml">

QuickLook/ViewWindowManager.cs

@@ -4,6 +4,7 @@ using System.IO;
 using System.Linq;
 using System.Text;
 using System.Threading.Tasks;
+using System.Windows;
 using QuickLook.Helpers;
 using QuickLook.Plugin;
 
@@ -12,24 +13,29 @@ namespace QuickLook
     internal class ViewWindowManager
     {
         private static ViewWindowManager _instance;
+        private readonly MainWindowNoTransparent _viewWindowNoTransparent;
+        private readonly MainWindowTransparent _viewWindowTransparentTransparent;
 
-        private readonly MainWindow _viewWindow;
+        private MainWindowTransparent _currentMainWindow;
 
         internal ViewWindowManager()
         {
-            _viewWindow = new MainWindow();
+            _viewWindowTransparentTransparent = new MainWindowTransparent();
+            _viewWindowNoTransparent = new MainWindowNoTransparent();
+
+            _currentMainWindow = _viewWindowTransparentTransparent;
         }
 
         internal void InvokeRoutine(bool replaceView = false)
         {
-            if (replaceView && _viewWindow.IsLoaded && _viewWindow.Visibility != System.Windows.Visibility.Visible)
+            if (replaceView && _currentMainWindow.IsLoaded && _currentMainWindow.Visibility != Visibility.Visible)
                 return;
 
             if (!WindowHelper.IsFocusedControlExplorerItem())
                 if (!WindowHelper.IsFocusedWindowSelf())
                     return;
 
-            if (!replaceView && _viewWindow.BeginHide())
+            if (!replaceView && _currentMainWindow.BeginHide())
                 return;
 
             var path = GetCurrentSelection();
@@ -53,12 +59,21 @@ namespace QuickLook
         {
             try
             {
-                _viewWindow.UnloadPlugin();
+                _currentMainWindow.UnloadPlugin();
-                _viewWindow.BeginShow(matchedPlugin, path);
+
+                // switch window
+                var oldWindow = _currentMainWindow;
+                _currentMainWindow = matchedPlugin.AllowsTransparency
+                    ? _viewWindowTransparentTransparent
+                    : _viewWindowNoTransparent;
+                if (!ReferenceEquals(oldWindow, _currentMainWindow))
+                    oldWindow.BeginHide();
+
+                _currentMainWindow.BeginShow(matchedPlugin, path);
             }
             catch (Exception e) // if current plugin failed, switch to default one.
             {
-                _viewWindow.BeginHide();
+                _currentMainWindow.BeginHide();
 
                 TrayIconManager.GetInstance().ShowNotification("", $"Failed to preview {Path.GetFileName(path)}", true);