[Peek] Add support for preview handlers

.github/actions/spell-check/expect.txt

@@ -1430,6 +1430,7 @@ ppsi
 ppsid
 ppsrm
 ppsrree
+ppstm
 ppsz
 pptal
 ppv
@@ -1472,6 +1473,8 @@ psfi
 Psr
 psrm
 psrree
+pstatstg
+pstm
 pstr
 pstream
 pstrm
@@ -1826,6 +1829,7 @@ STDMETHODCALLTYPE
 STDMETHODIMP
 stefan
 Stereolithography
+STGC
 STGM
 STGMEDIUM
 sticpl
@@ -2191,6 +2195,7 @@ wnd
 WNDCLASS
 WNDCLASSEX
 WNDCLASSEXW
+WNDCLASSW
 WNDPROC
 wordpad
 workaround

src/modules/peek/Peek.Common/NativeMethods.txt

@@ -2,4 +2,8 @@
 _SHCONTF
 SIGDN
 SHGDNF
-SIATTRIBFLAGS
+SIATTRIBFLAGS
+IInitializeWithFile
+IInitializeWithStream
+IPreviewHandler
+IPreviewHandlerVisuals

src/modules/peek/Peek.FilePreviewer/Controls/ShellPreviewHandlerControl.xaml

@@ -0,0 +1,17 @@
+<!-- Copyright (c) Microsoft Corporation. All rights reserved. -->
+<!-- Licensed under the MIT License. See LICENSE in the project root for license information. -->
+
+<UserControl
+    x:Class="Peek.FilePreviewer.Controls.ShellPreviewHandlerControl"
+    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+    xmlns:local="using:Peek.FilePreviewer.Controls"
+    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
+    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
+    mc:Ignorable="d"
+    Loaded="UserControl_Loaded"
+    EffectiveViewportChanged="UserControl_EffectiveViewportChanged"
+    IsTabStop="True" GotFocus="UserControl_GotFocus"
+    ActualThemeChanged="{x:Bind UpdatePreviewerTheme}">
+
+</UserControl>

src/modules/peek/Peek.FilePreviewer/Controls/ShellPreviewHandlerControl.xaml.cs

@@ -0,0 +1,183 @@
+// Copyright (c) Microsoft Corporation
+// The Microsoft Corporation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System;
+using System.Runtime.CompilerServices;
+using Microsoft.UI;
+using Microsoft.UI.Xaml;
+using Microsoft.UI.Xaml.Controls;
+using Peek.FilePreviewer.Previewers;
+using Windows.Win32;
+using Windows.Win32.Foundation;
+using Windows.Win32.UI.Shell;
+using Windows.Win32.UI.WindowsAndMessaging;
+
+namespace Peek.FilePreviewer.Controls
+{
+    public unsafe sealed partial class ShellPreviewHandlerControl : UserControl
+    {
+        // Making this into a DependencyProperty causes a InvalidCastException
+        private IPreviewHandler? _source;
+
+        private HWND containerHwnd;
+        private WNDPROC containerWndProc;
+        private RECT controlRect;
+
+        public static readonly DependencyProperty LoadingStateProperty = DependencyProperty.Register(
+            nameof(LoadingState),
+            typeof(PreviewState),
+            typeof(ShellPreviewHandlerControl),
+            new PropertyMetadata(PreviewState.Uninitialized));
+
+        public PreviewState? LoadingState
+        {
+            get { return (PreviewState)GetValue(LoadingStateProperty); }
+            set { SetValue(LoadingStateProperty, value); }
+        }
+
+        public IPreviewHandler? Source
+        {
+            get => _source;
+            set
+            {
+                _source = value;
+                SourcePropertyChanged();
+            }
+        }
+
+        public ShellPreviewHandlerControl()
+        {
+            InitializeComponent();
+
+            containerWndProc = ContainerWndProc;
+        }
+
+        private void SourcePropertyChanged()
+        {
+            if (Source != null)
+            {
+                UpdatePreviewerTheme();
+
+                try
+                {
+                    // Attach the preview handler to the container window
+                    Source.SetWindow(containerHwnd, (RECT*)Unsafe.AsPointer(ref controlRect));
+                    Source.DoPreview();
+
+                    PInvoke.ShowWindow(containerHwnd, SHOW_WINDOW_CMD.SW_SHOW);
+                }
+                catch
+                {
+                }
+            }
+            else
+            {
+                PInvoke.ShowWindow(containerHwnd, SHOW_WINDOW_CMD.SW_HIDE);
+            }
+        }
+
+        private void UpdatePreviewerTheme()
+        {
+            if (Source is IPreviewHandlerVisuals visuals)
+            {
+                try
+                {
+                    switch (ActualTheme)
+                    {
+                        case ElementTheme.Light:
+                            visuals.SetBackgroundColor(new COLORREF(0x00f3f3f3));
+                            visuals.SetTextColor(new COLORREF(0x00000000));
+                            break;
+
+                        case ElementTheme.Dark:
+                            visuals.SetBackgroundColor(new COLORREF(0x00202020));
+                            visuals.SetTextColor(new COLORREF(0x00FFFFFF));
+                            break;
+                    }
+
+                    // Changing the previewer colors might not always redraw itself
+                    PInvoke.InvalidateRect(containerHwnd, (RECT*)null, true);
+                }
+                catch
+                {
+                }
+            }
+        }
+
+        private LRESULT ContainerWndProc(HWND hWnd, uint msg, WPARAM wParam, LPARAM lParam)
+        {
+            // Here for future use :)
+            return PInvoke.DefWindowProc(hWnd, msg, wParam, lParam);
+        }
+
+        private void UserControl_Loaded(object sender, RoutedEventArgs e)
+        {
+            fixed (char* pContainerClassName = "PeekShellPreviewHandlerContainer")
+            {
+                PInvoke.RegisterClass(new WNDCLASSW()
+                {
+                    lpfnWndProc = containerWndProc,
+                    lpszClassName = pContainerClassName,
+                });
+
+                // Create the container window to host the preview handler
+                containerHwnd = PInvoke.CreateWindowEx(
+                    WINDOW_EX_STYLE.WS_EX_LAYERED,
+                    pContainerClassName,
+                    null,
+                    WINDOW_STYLE.WS_CHILD,
+                    0, // X
+                    0, // Y
+                    0, // Width
+                    0, // Height
+                    (HWND)Win32Interop.GetWindowFromWindowId(XamlRoot.ContentIslandEnvironment.AppWindowId), // Peek UI window
+                    HMENU.Null,
+                    HINSTANCE.Null);
+
+                // Allows the preview handlers to display properly
+                PInvoke.SetLayeredWindowAttributes(containerHwnd, default, byte.MaxValue, LAYERED_WINDOW_ATTRIBUTES_FLAGS.LWA_ALPHA);
+            }
+        }
+
+        private void UserControl_EffectiveViewportChanged(FrameworkElement sender, EffectiveViewportChangedEventArgs args)
+        {
+            var dpi = (float)PInvoke.GetDpiForWindow(containerHwnd) / 96;
+
+            // Resize the container window
+            PInvoke.SetWindowPos(
+                containerHwnd,
+                (HWND)0, // HWND_TOP
+                (int)(Math.Abs(args.EffectiveViewport.X) * dpi),
+                (int)(Math.Abs(args.EffectiveViewport.Y) * dpi),
+                (int)(ActualWidth * dpi),
+                (int)(ActualHeight * dpi),
+                SET_WINDOW_POS_FLAGS.SWP_NOACTIVATE);
+
+            // Resize the preview handler window
+            controlRect.right = (int)(ActualWidth * dpi);
+            controlRect.bottom = (int)(ActualHeight * dpi);
+            try
+            {
+                Source?.SetRect((RECT*)Unsafe.AsPointer(ref controlRect));
+            }
+            catch
+            {
+            }
+
+            // Resizing the previewer might not always redraw itself
+            PInvoke.InvalidateRect(containerHwnd, (RECT*)null, false);
+        }
+
+        private void UserControl_GotFocus(object sender, RoutedEventArgs e)
+        {
+            try
+            {
+                Source?.SetFocus();
+            }
+            catch
+            {
+            }
+        }
+    }
+}

src/modules/peek/Peek.FilePreviewer/FilePreview.xaml

@@ -18,6 +18,11 @@
             VerticalAlignment="Center"
             IsActive="{x:Bind MatchPreviewState(Previewer.State, previewers:PreviewState.Loading), Mode=OneWay}" />
 
+        <controls:ShellPreviewHandlerControl
+            x:Name="ShellPreviewHandlerPreview"
+            LoadingState="{x:Bind ShellPreviewHandlerPreviewer.State, Mode=OneWay}"
+            Source="{x:Bind ShellPreviewHandlerPreviewer.Preview, Mode=OneWay}" />
+
         <Image
             x:Name="ImagePreview"
             MaxWidth="{x:Bind ImagePreviewer.MaxImageSize.Width, Mode=OneWay}"
@@ -59,7 +64,7 @@
             DirectoryCount="{x:Bind ArchivePreviewer.DirectoryCountText, Mode=OneWay}"
             Size="{x:Bind ArchivePreviewer.SizeText, Mode=OneWay}"
             Visibility="{x:Bind IsPreviewVisible(ArchivePreviewer, Previewer.State), Mode=OneWay}" />
-        
+
         <controls:UnsupportedFilePreview
             x:Name="UnsupportedFilePreview"
             LoadingState="{x:Bind UnsupportedFilePreviewer.State, Mode=OneWay}"

src/modules/peek/Peek.FilePreviewer/FilePreview.xaml.cs

@@ -49,6 +49,7 @@ public sealed partial class FilePreview : UserControl, IDisposable
         [NotifyPropertyChangedFor(nameof(VideoPreviewer))]
         [NotifyPropertyChangedFor(nameof(BrowserPreviewer))]
         [NotifyPropertyChangedFor(nameof(ArchivePreviewer))]
+        [NotifyPropertyChangedFor(nameof(ShellPreviewHandlerPreviewer))]
         [NotifyPropertyChangedFor(nameof(UnsupportedFilePreviewer))]
 
         private IPreviewer? previewer;
@@ -96,6 +97,8 @@ private async void Previewer_PropertyChanged(object? sender, System.ComponentMod
 
         public IArchivePreviewer? ArchivePreviewer => Previewer as IArchivePreviewer;
 
+        public IShellPreviewHandlerPreviewer? ShellPreviewHandlerPreviewer => Previewer as IShellPreviewHandlerPreviewer;
+
         public IUnsupportedFilePreviewer? UnsupportedFilePreviewer => Previewer as IUnsupportedFilePreviewer;
 
         public IFileSystemItem Item
@@ -220,6 +223,9 @@ partial void OnPreviewerChanging(IPreviewer? value)
             ArchivePreview.Source = null;
             BrowserPreview.Source = null;
 
+            ShellPreviewHandlerPreviewer?.Clear();
+            ShellPreviewHandlerPreview.Source = null;
+
             if (Previewer != null)
             {
                 Previewer.PropertyChanged -= Previewer_PropertyChanged;

src/modules/peek/Peek.FilePreviewer/NativeMethods.json

@@ -0,0 +1,4 @@
+{
+    "$schema": "https://aka.ms/CsWin32.schema.json",
+    "public": false
+}

src/modules/peek/Peek.FilePreviewer/NativeMethods.txt

@@ -0,0 +1,8 @@
+CreateWindowEx
+DefWindowProc
+GetDpiForWindow
+InvalidateRect
+RegisterClass
+SetLayeredWindowAttributes
+SetWindowPos
+ShowWindow

src/modules/peek/Peek.FilePreviewer/Peek.FilePreviewer.csproj

@@ -8,6 +8,7 @@
     <RuntimeIdentifiers>win10-x86;win10-x64;win10-arm64</RuntimeIdentifiers>
     <UseWinUI>true</UseWinUI>
     <Nullable>enable</Nullable>
+    <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
   </PropertyGroup>
   <ItemGroup>
       <PRIResource Include="..\Peek.UI\Strings\en-US\Resources.resw" Link="Strings\en-US\Resources.resw">
@@ -17,6 +18,7 @@
   <ItemGroup>
     <None Remove="Controls\ArchiveControl.xaml" />
     <None Remove="Controls\BrowserControl.xaml" />
+    <None Remove="Controls\ShellPreviewHandlerControl.xaml" />
     <None Remove="Controls\UnsupportedFilePreview\FailedFallbackPreviewControl.xaml" />
     <None Remove="Controls\UnsupportedFilePreview\InformationalPreviewControl.xaml" />
     <None Remove="FilePreview.xaml" />
@@ -29,6 +31,10 @@
       <PackageReference Include="Microsoft.Windows.SDK.BuildTools" />
       <PackageReference Include="SharpCompress" />
       <PackageReference Include="System.Drawing.Common" />
+      <PackageReference Include="Microsoft.Windows.CsWin32">
+        <PrivateAssets>all</PrivateAssets>
+        <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
+      </PackageReference>
   </ItemGroup>
 
   <ItemGroup>
@@ -38,6 +44,12 @@
     <ProjectReference Include="..\Peek.Common\Peek.Common.csproj" />
   </ItemGroup>
 
+  <ItemGroup>
+    <Page Update="Controls\ShellPreviewHandlerControl.xaml">
+      <Generator>MSBuild:Compile</Generator>
+    </Page>
+  </ItemGroup>
+
   <ItemGroup>
     <Page Update="Controls\ArchiveControl.xaml">
       <Generator>MSBuild:Compile</Generator>

src/modules/peek/Peek.FilePreviewer/Previewers/Interfaces/IShellPreviewHandlerPreviewer.cs

@@ -0,0 +1,15 @@
+// Copyright (c) Microsoft Corporation
+// The Microsoft Corporation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using Windows.Win32.UI.Shell;
+
+namespace Peek.FilePreviewer.Previewers
+{
+    public interface IShellPreviewHandlerPreviewer : IPreviewer
+    {
+        public IPreviewHandler? Preview { get; }
+
+        public void Clear();
+    }
+}

src/modules/peek/Peek.FilePreviewer/Previewers/PreviewerFactory.cs

@@ -29,6 +29,10 @@ public IPreviewer Create(IFileSystemItem file)
             {
                 return new ArchivePreviewer(file);
             }
+            else if (ShellPreviewHandlerPreviewer.IsFileTypeSupported(file.Extension))
+            {
+                return new ShellPreviewHandlerPreviewer(file);
+            }
 
             // Other previewer types check their supported file types here
             return CreateDefaultPreviewer(file);