implement NativeTheme API with shouldUseDarkColors

Author: GregorBiswanger

ElectronNET.API/Electron.cs

@@ -78,5 +78,10 @@ public static class Electron
         /// Allows you to execute native Lock and Unlock process.       
         /// </summary>
         public static PowerMonitor PowerMonitor { get { return PowerMonitor.Instance; } }
+
+        /// <summary>
+        /// Read and respond to changes in Chromium's native color theme.
+        /// </summary>
+        public static NativeTheme NativeTheme { get { return NativeTheme.Instance; } }
     }
 }

ElectronNET.API/NativeTheme.cs

@@ -0,0 +1,55 @@
+using System.Threading.Tasks;
+
+namespace ElectronNET.API
+{
+    /// <summary>
+    /// Read and respond to changes in Chromium's native color theme.
+    /// </summary>
+    public sealed class NativeTheme
+    {
+        private static NativeTheme _nativeTheme;
+        private static object _syncRoot = new object();
+
+        internal NativeTheme() { }
+
+        internal static NativeTheme Instance
+        {
+            get
+            {
+                if (_nativeTheme == null)
+                {
+                    lock (_syncRoot)
+                    {
+                        if (_nativeTheme == null)
+                        {
+                            _nativeTheme = new NativeTheme();
+                        }
+                    }
+                }
+
+                return _nativeTheme;
+            }
+        }
+
+        /// <summary>
+        /// A `Boolean` for if the OS / Chromium currently has a dark mode enabled or is
+        /// being instructed to show a dark-style UI.If you want to modify this value you
+        /// should use `themeSource` below.
+        /// </summary>
+        /// <returns></returns>
+        public Task<bool> ShouldUseDarkColorsAsync()
+        {
+            var taskCompletionSource = new TaskCompletionSource<bool>();
+
+            BridgeConnector.Socket.On("nativeTheme-shouldUseDarkColors-completed", (shouldUseDarkColors) => {
+                BridgeConnector.Socket.Off("nativeTheme-shouldUseDarkColors-completed");
+
+                taskCompletionSource.SetResult((bool)shouldUseDarkColors);
+            });
+
+            BridgeConnector.Socket.Emit("nativeTheme-shouldUseDarkColors");
+
+            return taskCompletionSource.Task;
+        }
+    }
+}

ElectronNET.CLI/Commands/Actions/DeployEmbeddedElectronFiles.cs

@@ -31,6 +31,7 @@ public static void Do(string tempPath)
             EmbeddedFileHelper.DeployEmbeddedFile(hostApiFolder, "autoUpdater.js", "api.");
             EmbeddedFileHelper.DeployEmbeddedFile(hostApiFolder, "browserView.js", "api.");
             EmbeddedFileHelper.DeployEmbeddedFile(hostApiFolder, "powerMonitor.js", "api.");
+            EmbeddedFileHelper.DeployEmbeddedFile(hostApiFolder, "nativeTheme.js", "api.");
 
             string splashscreenFolder = Path.Combine(tempPath, "splashscreen");
             if (Directory.Exists(splashscreenFolder) == false)

ElectronNET.CLI/ElectronNET.CLI.csproj

@@ -72,6 +72,7 @@
     <EmbeddedResource Include="..\ElectronNET.Host\api\autoUpdater.js" Link="ElectronHost\api\autoUpdater.js" />
     <EmbeddedResource Include="..\ElectronNET.Host\api\browserView.js" Link="ElectronHost\api\browserView.js" />
     <EmbeddedResource Include="..\ElectronNET.Host\api\powerMonitor.js" Link="ElectronHost\api\powerMonitor.js" />
+    <EmbeddedResource Include="..\ElectronNET.Host\api\nativeTheme.js" Link="ElectronHost\api\nativeTheme.js" />
   </ItemGroup>
 
   <ItemGroup>

ElectronNET.Host/api/nativeTheme.js

@@ -0,0 +1,12 @@
+import { nativeTheme } from 'electron';
+let electronSocket;
+
+export = (socket: SocketIO.Socket) => {
+    electronSocket = socket;
+
+    socket.on('nativeTheme-shouldUseDarkColors', () => {
+        const shouldUseDarkColors = nativeTheme.shouldUseDarkColors;
+
+        electronSocket.emit('nativeTheme-shouldUseDarkColors-completed', shouldUseDarkColors);
+    });
+};

ElectronNET.Host/api/nativeTheme.js.map

@@ -10,7 +10,7 @@ let globalShortcut, shellApi, screen, clipboard, autoUpdater;
 let commandLine, browserView;
 let powerMonitor;
 let splashScreen, hostHook;
-let mainWindowId;
+let mainWindowId, nativeTheme;
 
 let manifestJsonFileName = 'electron.manifest.json';
 let watchable = false;
@@ -154,6 +154,7 @@ function startSocketApiBridge(port) {
             delete require.cache[require.resolve('./api/clipboard')];
             delete require.cache[require.resolve('./api/browserView')];
             delete require.cache[require.resolve('./api/powerMonitor')];
+            delete require.cache[require.resolve('./api/nativeTheme')];
         });
 
         global['electronsocket'] = socket;
@@ -176,6 +177,7 @@ function startSocketApiBridge(port) {
         clipboard = require('./api/clipboard')(socket);
         browserView = require('./api/browserView')(socket);
         powerMonitor = require('./api/powerMonitor')(socket);
+        nativeTheme = require('./api/nativeTheme')(socket);
 
         try {
             const hostHookScriptFilePath = path.join(__dirname, 'ElectronHostHook', 'index.js');