Add CHM viewer plugin (WebView2-based)

This commit does not implement the file link

QuickLook.Plugin/QuickLook.Plugin.ChmViewer/.gitattributes

@@ -0,0 +1,8 @@
+# Ignore HTML files in Resources and subdirectories
+Resources/**/*.html linguist-vendored
+
+# Ignore CSS files in Resources and subdirectories
+Resources/**/*.css linguist-vendored
+
+# Ignore JS files in Resources and subdirectories
+Resources/**/*.js linguist-vendored

QuickLook.Plugin/QuickLook.Plugin.ChmViewer/ChmWebpagePanel.cs

@@ -0,0 +1,125 @@
+// Copyright © 2017-2026 QL-Win Contributors
+//
+// This file is part of QuickLook program.
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+using QuickLook.Plugin.HtmlViewer;
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Reflection;
+
+namespace QuickLook.Plugin.ChmViewer;
+
+public class ChmWebpagePanel : WebpagePanel
+{
+    private const string _resourcePrefix = "QuickLook.Plugin.ChmViewer.Resources.";
+    private static readonly Dictionary<string, byte[]> _resources = [];
+    private readonly byte[] _homePage;
+
+    static ChmWebpagePanel()
+    {
+        InitializeResources();
+    }
+
+    public ChmWebpagePanel()
+    {
+        _homePage = ReadResource("/chm2html.html") ?? [];
+    }
+
+    private static void InitializeResources()
+    {
+        if (_resources.Any())
+            return;
+
+        var assembly = Assembly.GetExecutingAssembly();
+        foreach (var resourceName in assembly.GetManifestResourceNames())
+        {
+            if (!resourceName.StartsWith(_resourcePrefix, StringComparison.Ordinal))
+                continue;
+
+            var relativePath = resourceName.Substring(_resourcePrefix.Length).Replace('\\', '/');
+            if (string.IsNullOrEmpty(relativePath))
+                continue;
+
+            using var stream = assembly.GetManifestResourceStream(resourceName);
+            if (stream == null)
+                continue;
+
+            using var memoryStream = new MemoryStream();
+            stream.CopyTo(memoryStream);
+            _resources[$"/{relativePath}"] = memoryStream.ToArray();
+        }
+    }
+
+    public void PreviewCompiledHtmlHelp(string path)
+    {
+        FallbackPath = Path.GetDirectoryName(path);
+
+        var chmFileUrl = Helper.FilePathToFileUrl(path);
+        var pluginUri = new Uri($"file://quicklook/?plugin=1&chm={Uri.EscapeDataString(chmFileUrl.AbsoluteUri)}");
+
+        NavigateToUri(pluginUri);
+    }
+
+    protected override void WebView_WebResourceRequested(object sender, Microsoft.Web.WebView2.Core.CoreWebView2WebResourceRequestedEventArgs args)
+    {
+        try
+        {
+            if (string.IsNullOrWhiteSpace(args.Request.Uri))
+            {
+                base.WebView_WebResourceRequested(sender, args);
+                return;
+            }
+
+            var requestedUri = new Uri(args.Request.Uri);
+            if (requestedUri.Scheme != "file")
+            {
+                base.WebView_WebResourceRequested(sender, args);
+                return;
+            }
+
+            var requestedPath = Uri.UnescapeDataString(requestedUri.AbsolutePath);
+            if (requestedPath == "/")
+            {
+                var response = _webView.CoreWebView2.Environment.CreateWebResourceResponse(
+                    new MemoryStream(_homePage), 200, "OK", MimeTypes.GetContentType(".html"));
+                args.Response = response;
+                return;
+            }
+
+            if (ContainsKey(requestedPath))
+            {
+                var response = _webView.CoreWebView2.Environment.CreateWebResourceResponse(
+                    ReadStream(requestedPath), 200, "OK", MimeTypes.GetContentType(Path.GetExtension(requestedPath)));
+                args.Response = response;
+                return;
+            }
+
+            base.WebView_WebResourceRequested(sender, args);
+        }
+        catch
+        {
+            base.WebView_WebResourceRequested(sender, args);
+        }
+    }
+
+    private static bool ContainsKey(string key) => _resources.ContainsKey(key);
+
+    private static Stream ReadStream(string key) => new MemoryStream(_resources[key]);
+
+    private static byte[] ReadResource(string key) => _resources.TryGetValue(key, out var value) ? value : null;
+}

QuickLook.Plugin/QuickLook.Plugin.ChmViewer/Helper.cs

@@ -0,0 +1,52 @@
+// Copyright © 2017-2026 QL-Win Contributors
+//
+// This file is part of QuickLook program.
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+using System;
+using System.IO;
+using System.Text;
+
+namespace QuickLook.Plugin.ChmViewer;
+
+internal static class Helper
+{
+    public static Uri FilePathToFileUrl(string filePath)
+    {
+        var uri = new StringBuilder();
+        foreach (var v in filePath)
+            if (v >= 'a' && v <= 'z' || v >= 'A' && v <= 'Z' || v >= '0' && v <= '9' ||
+                v == '+' || v == '/' || v == ':' || v == '.' || v == '-' || v == '_' || v == '~' ||
+                v > '\x80')
+                uri.Append(v);
+            else if (v == Path.DirectorySeparatorChar || v == Path.AltDirectorySeparatorChar)
+                uri.Append('/');
+            else
+                uri.Append($"%{(int)v:X2}");
+        if (uri.Length >= 2 && uri[0] == '/' && uri[1] == '/') // UNC path - Universal Naming Convention
+            uri.Insert(0, "file:");
+        else
+            uri.Insert(0, "file:///");
+
+        try
+        {
+            return new Uri(uri.ToString());
+        }
+        catch
+        {
+            return null;
+        }
+    }
+}

QuickLook.Plugin/QuickLook.Plugin.ChmViewer/Plugin.cs

@@ -24,7 +24,13 @@ namespace QuickLook.Plugin.ChmViewer;
 
 public sealed class Plugin : IViewer
 {
-    public int Priority => 0;
+    private ChmWebpagePanel _panel;
+
+    /// <summary>
+    /// The implementation of this plugin is better than following
+    /// https://github.com/emako/QuickLook.Plugin.SumatraPDFReader
+    /// </summary>
+    public int Priority => 2;
 
     public void Init()
     {
@@ -32,26 +38,29 @@ public sealed class Plugin : IViewer
 
     public bool CanHandle(string path)
     {
-        return false;
-#pragma warning disable CS0162 // Unreachable code detected
         return !Directory.Exists(path)
             && Path.GetExtension(path).Equals(".chm", StringComparison.OrdinalIgnoreCase);
-#pragma warning restore CS0162 // Unreachable code detected
     }
 
     public void Prepare(string path, ContextObject context)
     {
-        context.Title = Path.GetFileName(path);
-        context.IsBlocked = true;
-        context.PreferredSize = new Size { Width = 800, Height = 600 };
+        context.PreferredSize = new Size(1280, 720);
     }
 
     public void View(string path, ContextObject context)
     {
+        _panel = new ChmWebpagePanel();
+        _panel.PreviewCompiledHtmlHelp(path);
+
+        context.ViewerContent = _panel;
+        context.Title = Path.GetFileName(path);
         context.IsBusy = false;
     }
 
     public void Cleanup()
     {
+        _panel?.Dispose();
+        _panel = null;
+        GC.SuppressFinalize(this);
     }
 }

QuickLook.Plugin/QuickLook.Plugin.ChmViewer/QuickLook.Plugin.ChmViewer.csproj

@@ -76,6 +76,21 @@
             <Name>QuickLook.Common</Name>
             <Private>False</Private>
         </ProjectReference>
+        <ProjectReference Include="..\QuickLook.Plugin.HtmlViewer\QuickLook.Plugin.HtmlViewer.csproj">
+            <Project>{CE22A1F3-7F2C-4EC8-BFDE-B58D0EB625FC}</Project>
+            <Name>QuickLook.Plugin.HtmlViewer</Name>
+            <Private>False</Private>
+        </ProjectReference>
+    </ItemGroup>
+
+    <ItemGroup>
+        <PackageReference Include="Microsoft.Web.WebView2" Version="1.0.3912.50">
+            <PrivateAssets>all</PrivateAssets>
+        </PackageReference>
+    </ItemGroup>
+
+    <ItemGroup>
+        <EmbeddedResource Include="Resources\chm2html.html" />
     </ItemGroup>
 
 </Project>