Add theme toggle button to SVG and WebView2-based image previews

QuickLook.Plugin/QuickLook.Plugin.ImageViewer/Webview/Lottie/LottieImagePanel.cs

@@ -35,6 +35,10 @@ public override void Preview(string path)
         ObjectForScripting ??= new ScriptHandler(path);
 
         _homePage = _resources["/lottie2html.html"];
+
+        // Update WebView2 background color based on current theme
+        UpdateWebViewBackgroundColor();
+
         NavigateToUri(new Uri("file://quicklook/"));
     }
 

QuickLook.Plugin/QuickLook.Plugin.ImageViewer/Webview/Svg/SvgImagePanel.cs

@@ -18,6 +18,7 @@
 using Microsoft.Web.WebView2.Core;
 using Microsoft.Web.WebView2.Wpf;
 using QuickLook.Common.Helpers;
+using QuickLook.Common.Plugin;
 using QuickLook.Plugin.HtmlViewer;
 using System;
 using System.Collections.Generic;
@@ -29,17 +30,36 @@
 using System.Runtime.InteropServices;
 using System.Text;
 using System.Threading.Tasks;
+using System.Windows;
+using System.Windows.Controls;
 
 namespace QuickLook.Plugin.ImageViewer.Webview.Svg;
 
-public class SvgImagePanel : WebpagePanel, IWebImagePanel
+public partial class SvgImagePanel : UserControl, IWebImagePanel
 {
     protected const string _resourcePrefix = "QuickLook.Plugin.ImageViewer.Resources.";
     protected internal static readonly Dictionary<string, byte[]> _resources = [];
     protected byte[] _homePage;
+    protected WebView2 _webView;
+    protected Uri _currentUri;
+    protected string _primaryPath;
+    protected string _fallbackPath;
+    private ContextObject _contextObject;
 
     private object _objectForScripting;
 
+    public string FallbackPath
+    {
+        get => _fallbackPath;
+        set => _fallbackPath = value;
+    }
+
+    public ContextObject ContextObject
+    {
+        get => _contextObject;
+        set => _contextObject = value;
+    }
+
     public object ObjectForScripting
     {
         get => _objectForScripting;
@@ -60,7 +80,21 @@ static SvgImagePanel()
         InitializeResources();
     }
 
-    protected override void InitializeComponent()
+    public SvgImagePanel()
+    {
+        InitializeComponent();
+
+        // Clear merged dictionaries from design time
+        Resources.MergedDictionaries.Clear();
+
+        // Initialize WebView2
+        InitializeWebView();
+
+        // Wire up the theme toggle button
+        buttonBackgroundColour.Click += OnBackgroundColourOnClick;
+    }
+
+    protected void InitializeWebView()
     {
         _webView = new WebView2()
         {
@@ -71,7 +105,53 @@ protected override void InitializeComponent()
             DefaultBackgroundColor = Color.Transparent,
         };
         _webView.CoreWebView2InitializationCompleted += WebView_CoreWebView2InitializationCompleted;
-        Content = _webView;
+
+        // Add WebView2 to the Grid at the first position (behind the button)
+        var grid = (Grid)Content;
+        grid.Children.Insert(0, _webView);
+    }
+
+    private void OnBackgroundColourOnClick(object sender, RoutedEventArgs e)
+    {
+        if (ContextObject == null) return;
+
+        // Toggle the theme
+        var newTheme = ContextObject.Theme == Themes.Dark ? Themes.Light : Themes.Dark;
+        ContextObject.Theme = newTheme;
+
+        // Save the theme preference
+        SettingHelper.Set("LastTheme", (int)newTheme, "QuickLook.Plugin.ImageViewer");
+
+        // Update WebView2 background color
+        UpdateWebViewBackgroundColor();
+    }
+
+    protected void UpdateWebViewBackgroundColor()
+    {
+        if (_webView == null) return;
+
+        var isDark = ContextObject?.Theme == Themes.Dark;
+        _webView.DefaultBackgroundColor = isDark 
+            ? Color.FromArgb(255, 32, 32, 32) 
+            : Color.White;
+    }
+
+    public void NavigateToUri(Uri uri)
+    {
+        if (_webView == null)
+            return;
+
+        _webView.Source = uri;
+        _currentUri = _webView.Source;
+    }
+
+    protected virtual void WebView_CoreWebView2InitializationCompleted(object sender, CoreWebView2InitializationCompletedEventArgs e)
+    {
+        if (e.IsSuccess)
+        {
+            _webView.CoreWebView2.AddWebResourceRequestedFilter("*", CoreWebView2WebResourceContext.All);
+            _webView.CoreWebView2.WebResourceRequested += WebView_WebResourceRequested;
+        }
     }
 
     protected static void InitializeResources()
@@ -102,10 +182,14 @@ public virtual void Preview(string path)
         ObjectForScripting ??= new ScriptHandler(path);
 
         _homePage = _resources["/svg2html.html"];
+
+        // Update WebView2 background color based on current theme
+        UpdateWebViewBackgroundColor();
+
         NavigateToUri(new Uri("file://quicklook/"));
     }
 
-    protected override void WebView_WebResourceRequested(object sender, CoreWebView2WebResourceRequestedEventArgs args)
+    protected virtual void WebView_WebResourceRequested(object sender, CoreWebView2WebResourceRequestedEventArgs args)
     {
         Debug.WriteLine($"[{args.Request.Method}] {args.Request.Uri}");
 
@@ -186,7 +270,13 @@ public static string ReadString(string key)
         return reader.ReadToEnd();
     }
 
-    public new static class MimeTypes
+    public void Dispose()
+    {
+        _webView?.Dispose();
+        _webView = null;
+    }
+
+    public static class MimeTypes
     {
         public static string GetContentTypeHeader(string extension = null)
             => $"Content-Type: {WebpagePanel.MimeTypes.GetMimeType(extension)}";

QuickLook.Plugin/QuickLook.Plugin.ImageViewer/Webview/Svg/SvgImagePanel.xaml

@@ -0,0 +1,32 @@
+<UserControl x:Class="QuickLook.Plugin.ImageViewer.Webview.Svg.SvgImagePanel"
+             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+             xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
+             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
+             x:Name="svgImagePanel"
+             d:DesignHeight="300"
+             d:DesignWidth="300"
+             mc:Ignorable="d">
+    <UserControl.Resources>
+        <ResourceDictionary>
+            <ResourceDictionary.MergedDictionaries>
+                <!--  only for design  -->
+                <ResourceDictionary Source="/QuickLook.Common;component/Styles/MainWindowStyles.xaml" />
+                <ResourceDictionary Source="/QuickLook.Common;component/Styles/MainWindowStyles.Dark.xaml" />
+            </ResourceDictionary.MergedDictionaries>
+        </ResourceDictionary>
+    </UserControl.Resources>
+    <Grid>
+        <!-- WebView2 will be added here programmatically -->
+        <StackPanel Margin="0,8,8,0"
+                    HorizontalAlignment="Right"
+                    VerticalAlignment="Top"
+                    Orientation="Horizontal">
+            <Button x:Name="buttonBackgroundColour"
+                    Width="24"
+                    Height="24"
+                    Content="&#xEF1F;"
+                    Style="{StaticResource CaptionButtonStyle}" />
+        </StackPanel>
+    </Grid>
+</UserControl>

QuickLook.Plugin/QuickLook.Plugin.ImageViewer/Webview/Svga/SvgaImagePanel.cs

@@ -34,6 +34,10 @@ public override void Preview(string path)
         ObjectForScripting ??= new ScriptHandler(path, _metaWeb);
 
         _homePage = _resources["/svga2html.html"];
+
+        // Update WebView2 background color based on current theme
+        UpdateWebViewBackgroundColor();
+
         NavigateToUri(new Uri("file://quicklook/"));
     }
 }

QuickLook.Plugin/QuickLook.Plugin.ImageViewer/Webview/Tgs/TgsImagePanel.cs

@@ -35,6 +35,10 @@ public override void Preview(string path)
         ObjectForScripting ??= new TgsScriptHandler(path);
 
         _homePage = _resources["/lottie2html.html"];
+
+        // Update WebView2 background color based on current theme
+        UpdateWebViewBackgroundColor();
+
         NavigateToUri(new Uri("file://quicklook/"));
     }
 

QuickLook.Plugin/QuickLook.Plugin.ImageViewer/Webview/WebHandler.cs

@@ -102,10 +102,10 @@ public static bool TryView(string path, ContextObject context, IWebMetaProvider
 
             ipWeb = ext switch
             {
-                ".svg" => new SvgImagePanel(),
-                ".svga" => new SvgaImagePanel(metaWeb),
-                ".lottie" or ".json" => new LottieImagePanel(),
-                ".tgs" => new TgsImagePanel(),
+                ".svg" => new SvgImagePanel() { ContextObject = context },
+                ".svga" => new SvgaImagePanel(metaWeb) { ContextObject = context },
+                ".lottie" or ".json" => new LottieImagePanel() { ContextObject = context },
+                ".tgs" => new TgsImagePanel() { ContextObject = context },
                 _ => throw new NotSupportedException($"Unsupported file type: {ext}")
             };