#1080: dark theme support for the text viewer

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

@@ -16,6 +16,7 @@
 // along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 using System.Collections.Generic;
+using System.Diagnostics;
 using System.IO;
 using System.Linq;
 using System.Reflection;
@@ -25,6 +26,7 @@ using System.Xml;
 using ICSharpCode.AvalonEdit;
 using ICSharpCode.AvalonEdit.Highlighting;
 using ICSharpCode.AvalonEdit.Highlighting.Xshd;
+using QuickLook.Common.Helpers;
 using QuickLook.Common.Plugin;
 
 namespace QuickLook.Plugin.TextViewer
@@ -33,33 +35,18 @@ namespace QuickLook.Plugin.TextViewer
     {
         private TextViewerPanel _tvp;
 
+        private static HighlightingManager _hlmLight;
+        private static HighlightingManager _hlmDark;
+
         public int Priority => -5;
 
         public void Init()
         {
-            var hlm = HighlightingManager.Instance;
-
-            var assemblyPath = Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location);
-            if (string.IsNullOrEmpty(assemblyPath)) return;
-
-            var syntaxPath = Path.Combine(assemblyPath, "Syntax");
-            if (!Directory.Exists(syntaxPath)) return;
-
-            foreach (var file in Directory.EnumerateFiles(syntaxPath, "*.xshd"))
-            {
-                var ext = Path.GetFileNameWithoutExtension(file);
-                using (Stream s = File.OpenRead(Path.GetFullPath(file)))
-                using (var reader = new XmlTextReader(s))
-                {
-                    var xshd = HighlightingLoader.LoadXshd(reader);
-                    var highlightingDefinition = HighlightingLoader.Load(xshd, hlm);
-                    if (xshd.Extensions.Count > 0)
-                        hlm.RegisterHighlighting(ext, xshd.Extensions.ToArray(), highlightingDefinition);
-                }
-            }
-
             // pre-load
             var _ = new TextEditor();
+
+            _hlmLight = getHighlightingManager(Themes.Light, "Light");
+            _hlmDark = getHighlightingManager(Themes.Dark, "Dark");
         }
 
         public bool CanHandle(string path)
@@ -87,8 +74,6 @@ namespace QuickLook.Plugin.TextViewer
 
         public void Prepare(string path, ContextObject context)
         {
-            //context.Theme = Themes.Light;
-
             context.PreferredSize = new Size {Width = 800, Height = 600};
         }
 
@@ -109,6 +94,8 @@ namespace QuickLook.Plugin.TextViewer
             else
             {
                 _tvp = new TextViewerPanel(path, context);
+                AssignHighlightingManager(_tvp, context);
+
                 context.ViewerContent = _tvp;
             }
             context.Title = $"{Path.GetFileName(path)}";
@@ -128,5 +115,39 @@ namespace QuickLook.Plugin.TextViewer
 
             return true;
         }
+
+        private HighlightingManager getHighlightingManager(Themes theme, string dirName)
+        {
+            var hlm = new HighlightingManager();
+
+            var assemblyPath = Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location);
+            if (string.IsNullOrEmpty(assemblyPath))
+                return hlm;
+
+            var syntaxPath = Path.Combine(assemblyPath, "Syntax", dirName);
+            if (!Directory.Exists(syntaxPath))
+                return hlm;
+
+            foreach (var file in Directory.EnumerateFiles(syntaxPath, "*.xshd"))
+            {
+                Debug.WriteLine(file);
+                var ext = Path.GetFileNameWithoutExtension(file);
+                using (Stream s = File.OpenRead(Path.GetFullPath(file)))
+                using (var reader = new XmlTextReader(s))
+                {
+                    var xshd = HighlightingLoader.LoadXshd(reader);
+                    var highlightingDefinition = HighlightingLoader.Load(xshd, hlm);
+                    if (xshd.Extensions.Count > 0)
+                        hlm.RegisterHighlighting(ext, xshd.Extensions.ToArray(), highlightingDefinition);
+                }
+            }
+
+            return hlm;
+        }
+        private void AssignHighlightingManager(TextViewerPanel tvp, ContextObject context)
+        {
+            var isDark = (context.Theme == Themes.Dark) | OSThemeHelper.AppsUseDarkTheme() | false;
+            tvp.HighlightingManager = isDark ? _hlmDark : _hlmLight;
+        }
     }
 }

QuickLook.Plugin/QuickLook.Plugin.TextViewer/QuickLook.Plugin.TextViewer.csproj

@@ -57,8 +57,8 @@
     </AssemblyOriginatorKeyFile>
   </PropertyGroup>
   <ItemGroup>
-    <Reference Include="ICSharpCode.AvalonEdit, Version=6.1.2.30, Culture=neutral, PublicKeyToken=9cc39be672370310, processorArchitecture=MSIL">
-      <HintPath>..\..\packages\AvalonEdit.6.1.2.30\lib\net45\ICSharpCode.AvalonEdit.dll</HintPath>
+    <Reference Include="ICSharpCode.AvalonEdit, Version=6.1.3.50, Culture=neutral, PublicKeyToken=9cc39be672370310, processorArchitecture=MSIL">
+      <HintPath>..\..\packages\AvalonEdit.6.1.3.50\lib\net45\ICSharpCode.AvalonEdit.dll</HintPath>
     </Reference>
     <Reference Include="PresentationCore" />
     <Reference Include="PresentationFramework" />
@@ -89,8 +89,9 @@
   </ItemGroup>
   <ItemGroup>
     <Content Include="Syntax\**">
-      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
+      <CopyToOutputDirectory>None</CopyToOutputDirectory>
     </Content>
+    <None Include="app.config" />
     <None Include="packages.config" />
     <None Include="Translations.config">
       <SubType>Designer</SubType>

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

@@ -39,12 +39,14 @@ namespace QuickLook.Plugin.TextViewer
     {
         private readonly ContextObject _context;
         private bool _disposed;
+        private HighlightingManager highlightingManager = HighlightingManager.Instance;
 
         public TextViewerPanel(string path, ContextObject context)
         {
             _context = context;
 
-            Background = new SolidColorBrush(Color.FromArgb(0xAA, 255, 255, 255));
+            SetResourceReference(Control.ForegroundProperty, "WindowTextForeground");
+            Background = Brushes.Transparent;
             FontSize = 14;
             ShowLineNumbers = true;
             WordWrap = true;
@@ -82,6 +84,12 @@ namespace QuickLook.Plugin.TextViewer
             LoadFileAsync(path);
         }
 
+        public HighlightingManager HighlightingManager
+        {
+            get => highlightingManager;
+            set => highlightingManager = value;
+        }
+
         public void Dispose()
         {
             _disposed = true;
@@ -185,7 +193,7 @@ namespace QuickLook.Plugin.TextViewer
                     Encoding = encoding;
                     SyntaxHighlighting = bufferCopy.Length > maxHighlightingLength
                         ? null
-                        : HighlightingManager.Instance.GetDefinitionByExtension(Path.GetExtension(path));
+                        : HighlightingManager?.GetDefinitionByExtension(Path.GetExtension(path));
                     Document = doc;
 
                     _context.IsBusy = false;

QuickLook.Plugin/QuickLook.Plugin.TextViewer/app.config

@@ -0,0 +1,11 @@
+<?xml version="1.0" encoding="utf-8"?>
+<configuration>
+  <runtime>
+    <assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">
+      <dependentAssembly>
+        <assemblyIdentity name="ICSharpCode.AvalonEdit" publicKeyToken="9cc39be672370310" culture="neutral" />
+        <bindingRedirect oldVersion="0.0.0.0-6.1.3.50" newVersion="6.1.3.50" />
+      </dependentAssembly>
+    </assemblyBinding>
+  </runtime>
+</configuration>

QuickLook.Plugin/QuickLook.Plugin.TextViewer/packages.config

@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
 <packages>
-  <package id="AvalonEdit" version="6.1.2.30" targetFramework="net462" />
+  <package id="AvalonEdit" version="6.1.3.50" targetFramework="net462" />
   <package id="UTF.Unknown" version="2.5.0" targetFramework="net462" />
 </packages>