SEBWIN-841: Implemented focus handler API in attempt to resolve issue…

… (without success).

SafeExamBrowser.Browser/BrowserControl.cs

@@ -26,6 +26,7 @@ internal class BrowserControl : IBrowserControl
 		private readonly IDialogHandler dialogHandler;
 		private readonly IDisplayHandler displayHandler;
 		private readonly IDownloadHandler downloadHandler;
+		private readonly IFocusHandler focusHandler;
 		private readonly IKeyboardHandler keyboardHandler;
 		private readonly ILogger logger;
 		private readonly IRenderProcessMessageHandler renderProcessMessageHandler;
@@ -47,6 +48,7 @@ public BrowserControl(
 			IDialogHandler dialogHandler,
 			IDisplayHandler displayHandler,
 			IDownloadHandler downloadHandler,
+			IFocusHandler focusHandler,
 			IKeyboardHandler keyboardHandler,
 			ILogger logger,
 			IRenderProcessMessageHandler renderProcessMessageHandler,
@@ -57,6 +59,7 @@ public BrowserControl(
 			this.dialogHandler = dialogHandler;
 			this.displayHandler = displayHandler;
 			this.downloadHandler = downloadHandler;
+			this.focusHandler = focusHandler;
 			this.keyboardHandler = keyboardHandler;
 			this.logger = logger;
 			this.renderProcessMessageHandler = renderProcessMessageHandler;
@@ -128,6 +131,7 @@ public void Initialize()
 			control.FaviconUrlChanged += (w, b, u) => displayHandler.OnFaviconUrlChange(w, b, u);
 			control.FileDialogRequested += (w, b, m, t, p, f, e, d, c) => dialogHandler.OnFileDialog(w, b, m, t, p, f, e, d, c);
 			control.FocusedNodeChanged += (w, b, f, n) => renderProcessMessageHandler.OnFocusedNodeChanged(w, b, f, n);
+			control.GotFocusCefSharp += (w, b) => focusHandler.OnGotFocus(w, b);
 			control.IsBrowserInitializedChanged += Control_IsBrowserInitializedChanged;
 			control.KeyEvent += (w, b, t, k, n, m, s) => keyboardHandler.OnKeyEvent(w, b, t, k, n, m, s);
 			control.LoadError += (o, e) => LoadFailed?.Invoke((int) e.ErrorCode, e.ErrorText, e.Frame.IsMain, e.FailedUrl);
@@ -136,6 +140,8 @@ public void Initialize()
 			control.OpenUrlFromTab += (w, b, f, u, t, g, a) => a.Value = requestHandler.OnOpenUrlFromTab(w, b, f, u, t, g);
 			control.PreKeyEvent += (IWebBrowser w, IBrowser b, KeyType t, int k, int n, CefEventFlags m, bool i, ref bool s, GenericEventArgs a) => a.Value = keyboardHandler.OnPreKeyEvent(w, b, t, k, n, m, i, ref s);
 			control.ResourceRequestHandlerRequired += (IWebBrowser w, IBrowser b, IFrame f, IRequest r, bool n, bool d, string i, ref bool h, ResourceRequestEventArgs a) => a.Handler = requestHandler.GetResourceRequestHandler(w, b, f, r, n, d, i, ref h);
+			control.SetFocus += (w, b, s, a) => a.Value = focusHandler.OnSetFocus(w, b, s);
+			control.TakeFocus += (w, b, n) => focusHandler.OnTakeFocus(w, b, n);
 			control.TitleChanged += (o, e) => TitleChanged?.Invoke(e.Title);
 			control.UncaughtExceptionEvent += (w, b, f, e) => renderProcessMessageHandler.OnUncaughtException(w, b, f, e);
 

SafeExamBrowser.Browser/BrowserWindow.cs

@@ -157,6 +157,7 @@ internal void InitializeControl()
 			var displayHandler = new DisplayHandler();
 			var downloadLogger = logger.CloneFor($"{nameof(DownloadHandler)} #{Id}");
 			var downloadHandler = new DownloadHandler(appConfig, downloadLogger, settings, WindowSettings);
+			var focusHandler = new FocusHandler(logger.CloneFor($"{nameof(FocusHandler)} #{Id}"));
 			var keyboardHandler = new KeyboardHandler();
 			var renderHandler = new RenderProcessMessageHandler(appConfig, clipboard, keyGenerator, settings, text);
 			var requestFilter = new RequestFilter();
@@ -195,7 +196,7 @@ internal void InitializeControl()
 
 			InitializeRequestFilter(requestFilter);
 
-			Control = new BrowserControl(clipboard, cefSharpControl, dialogHandler, displayHandler, downloadHandler, keyboardHandler, controlLogger, renderHandler, requestHandler);
+			Control = new BrowserControl(clipboard, cefSharpControl, dialogHandler, displayHandler, downloadHandler, focusHandler, keyboardHandler, controlLogger, renderHandler, requestHandler);
 			Control.AddressChanged += Control_AddressChanged;
 			Control.LoadFailed += Control_LoadFailed;
 			Control.LoadingStateChanged += Control_LoadingStateChanged;

SafeExamBrowser.Browser/Handlers/FocusHandler.cs

@@ -0,0 +1,36 @@
+/*
+ * Copyright (c) 2024 ETH Zürich, IT Services
+ * 
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+using CefSharp;
+using SafeExamBrowser.Logging.Contracts;
+
+namespace SafeExamBrowser.Browser.Handlers
+{
+	internal class FocusHandler : IFocusHandler
+	{
+		private readonly ILogger logger;
+
+		internal FocusHandler(ILogger logger)
+		{
+			this.logger = logger;
+		}
+
+		public void OnGotFocus(IWebBrowser webBrowser, IBrowser browser)
+		{
+		}
+
+		public bool OnSetFocus(IWebBrowser webBrowser, IBrowser browser, CefFocusSource source)
+		{
+			return true;
+		}
+
+		public void OnTakeFocus(IWebBrowser webBrowser, IBrowser browser, bool next)
+		{
+		}
+	}
+}

SafeExamBrowser.Browser/SafeExamBrowser.Browser.csproj

@@ -103,6 +103,7 @@
     <Compile Include="Handlers\DialogHandler.cs" />
     <Compile Include="Handlers\DisplayHandler.cs" />
     <Compile Include="Handlers\DownloadHandler.cs" />
+    <Compile Include="Handlers\FocusHandler.cs" />
     <Compile Include="Handlers\KeyboardHandler.cs" />
     <Compile Include="Handlers\RenderProcessMessageHandler.cs" />
     <Compile Include="Handlers\RequestHandler.cs" />
@@ -125,18 +126,22 @@
     <Compile Include="Wrapper\Events\FaviconUrlChangedEventHandler.cs" />
     <Compile Include="Wrapper\Events\FileDialogRequestedEventHandler.cs" />
     <Compile Include="Wrapper\Events\FocusedNodeChangedEventHandler.cs" />
+    <Compile Include="Wrapper\Events\GotFocusEventHandler.cs" />
     <Compile Include="Wrapper\Events\KeyEventHandler.cs" />
     <Compile Include="Wrapper\Events\LoadingProgressChangedEventHandler.cs" />
     <Compile Include="Wrapper\Events\GenericEventArgs.cs" />
     <Compile Include="Wrapper\Events\OpenUrlFromTabEventHandler.cs" />
     <Compile Include="Wrapper\Events\PreKeyEventHandler.cs" />
     <Compile Include="Wrapper\Events\ResourceRequestEventArgs.cs" />
     <Compile Include="Wrapper\Events\ResourceRequestEventHandler.cs" />
+    <Compile Include="Wrapper\Events\SetFocusEventHandler.cs" />
+    <Compile Include="Wrapper\Events\TakeFocusEventHandler.cs" />
     <Compile Include="Wrapper\Events\UncaughtExceptionEventHandler.cs" />
     <Compile Include="Wrapper\Extensions.cs" />
     <Compile Include="Wrapper\Handlers\DialogHandlerSwitch.cs" />
     <Compile Include="Wrapper\Handlers\DisplayHandlerSwitch.cs" />
     <Compile Include="Wrapper\Handlers\DownloadHandlerSwitch.cs" />
+    <Compile Include="Wrapper\Handlers\FocusHandlerSwitch.cs" />
     <Compile Include="Wrapper\Handlers\KeyboardHandlerSwitch.cs" />
     <Compile Include="Wrapper\Handlers\RenderProcessMessageHandlerSwitch.cs" />
     <Compile Include="Wrapper\Handlers\RequestHandlerSwitch.cs" />

SafeExamBrowser.Browser/Wrapper/CefSharpBrowserControl.cs

@@ -27,18 +27,22 @@ internal class CefSharpBrowserControl : ChromiumWebBrowser, ICefSharpControl
 		public event FaviconUrlChangedEventHandler FaviconUrlChanged;
 		public event FileDialogRequestedEventHandler FileDialogRequested;
 		public event FocusedNodeChangedEventHandler FocusedNodeChanged;
+		public event GotFocusEventHandler GotFocusCefSharp;
 		public event KeyEventHandler KeyEvent;
 		public event LoadingProgressChangedEventHandler LoadingProgressChanged;
 		public event OpenUrlFromTabEventHandler OpenUrlFromTab;
 		public event PreKeyEventHandler PreKeyEvent;
 		public event ResourceRequestEventHandler ResourceRequestHandlerRequired;
+		public event SetFocusEventHandler SetFocus;
+		public event TakeFocusEventHandler TakeFocus;
 		public event UncaughtExceptionEventHandler UncaughtExceptionEvent;
 
 		public CefSharpBrowserControl(ILifeSpanHandler lifeSpanHandler, string url) : base(url)
 		{
 			DialogHandler = new DialogHandlerSwitch();
 			DisplayHandler = new DisplayHandlerSwitch();
 			DownloadHandler = new DownloadHandlerSwitch();
+			FocusHandler = new FocusHandlerSwitch();
 			KeyboardHandler = new KeyboardHandlerSwitch();
 			LifeSpanHandler = lifeSpanHandler;
 			MenuHandler = new ContextMenuHandler();
@@ -106,6 +110,11 @@ public void OnFocusedNodeChanged(IWebBrowser webBrowser, IBrowser browser, IFram
 			FocusedNodeChanged?.Invoke(webBrowser, browser, frame, node);
 		}
 
+		public void OnGotFocus(IWebBrowser webBrowser, IBrowser browser)
+		{
+			GotFocusCefSharp?.Invoke(webBrowser, browser);
+		}
+
 		public void OnKeyEvent(IWebBrowser webBrowser, IBrowser browser, KeyType type, int windowsKeyCode, int nativeKeyCode, CefEventFlags modifiers, bool isSystemKey)
 		{
 			KeyEvent?.Invoke(webBrowser, browser, type, windowsKeyCode, nativeKeyCode, modifiers, isSystemKey);
@@ -126,6 +135,16 @@ public void OnPreKeyEvent(IWebBrowser webBrowser, IBrowser browser, KeyType type
 			PreKeyEvent?.Invoke(webBrowser, browser, type, windowsKeyCode, nativeKeyCode, modifiers, isSystemKey, ref isKeyboardShortcut, args);
 		}
 
+		public void OnSetFocus(IWebBrowser webBrowser, IBrowser browser, CefFocusSource source, GenericEventArgs args)
+		{
+			SetFocus?.Invoke(webBrowser, browser, source, args);
+		}
+
+		public void OnTakeFocus(IWebBrowser webBrowser, IBrowser browser, bool next)
+		{
+			TakeFocus?.Invoke(webBrowser, browser, next);
+		}
+
 		public void OnUncaughtException(IWebBrowser webBrowser, IBrowser browser, IFrame frame, JavascriptException exception)
 		{
 			UncaughtExceptionEvent?.Invoke(webBrowser, browser, frame, exception);

SafeExamBrowser.Browser/Wrapper/CefSharpPopupControl.cs

@@ -25,11 +25,14 @@ internal class CefSharpPopupControl : ChromiumHostControl, ICefSharpControl
 		public event FaviconUrlChangedEventHandler FaviconUrlChanged;
 		public event FileDialogRequestedEventHandler FileDialogRequested;
 		public event FocusedNodeChangedEventHandler FocusedNodeChanged;
+		public event GotFocusEventHandler GotFocusCefSharp;
 		public event KeyEventHandler KeyEvent;
 		public event LoadingProgressChangedEventHandler LoadingProgressChanged;
 		public event OpenUrlFromTabEventHandler OpenUrlFromTab;
 		public event PreKeyEventHandler PreKeyEvent;
 		public event ResourceRequestEventHandler ResourceRequestHandlerRequired;
+		public event SetFocusEventHandler SetFocus;
+		public event TakeFocusEventHandler TakeFocus;
 		public event UncaughtExceptionEventHandler UncaughtExceptionEvent;
 
 		void ICefSharpControl.Dispose(bool disposing)
@@ -100,6 +103,11 @@ public void OnFocusedNodeChanged(IWebBrowser webBrowser, IBrowser browser, IFram
 			FocusedNodeChanged?.Invoke(webBrowser, browser, frame, node);
 		}
 
+		public void OnGotFocus(IWebBrowser webBrowser, IBrowser browser)
+		{
+			GotFocusCefSharp?.Invoke(webBrowser, browser);
+		}
+
 		public void OnKeyEvent(IWebBrowser webBrowser, IBrowser browser, KeyType type, int windowsKeyCode, int nativeKeyCode, CefEventFlags modifiers, bool isSystemKey)
 		{
 			KeyEvent?.Invoke(webBrowser, browser, type, windowsKeyCode, nativeKeyCode, modifiers, isSystemKey);
@@ -120,6 +128,16 @@ public void OnPreKeyEvent(IWebBrowser webBrowser, IBrowser browser, KeyType type
 			PreKeyEvent?.Invoke(webBrowser, browser, type, windowsKeyCode, nativeKeyCode, modifiers, isSystemKey, ref isKeyboardShortcut, args);
 		}
 
+		public void OnSetFocus(IWebBrowser webBrowser, IBrowser browser, CefFocusSource source, GenericEventArgs args)
+		{
+			SetFocus?.Invoke(webBrowser, browser, source, args);
+		}
+
+		public void OnTakeFocus(IWebBrowser webBrowser, IBrowser browser, bool next)
+		{
+			TakeFocus?.Invoke(webBrowser, browser, next);
+		}
+
 		public void OnUncaughtException(IWebBrowser webBrowser, IBrowser browser, IFrame frame, JavascriptException exception)
 		{
 			UncaughtExceptionEvent?.Invoke(webBrowser, browser, frame, exception);

SafeExamBrowser.Browser/Wrapper/Events/GotFocusEventHandler.cs

@@ -0,0 +1,14 @@
+/*
+ * Copyright (c) 2024 ETH Zürich, IT Services
+ * 
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+using CefSharp;
+
+namespace SafeExamBrowser.Browser.Wrapper.Events
+{
+	internal delegate void GotFocusEventHandler(IWebBrowser webBrowser, IBrowser browser);
+}

SafeExamBrowser.Browser/Wrapper/Events/SetFocusEventHandler.cs

@@ -0,0 +1,14 @@
+/*
+ * Copyright (c) 2024 ETH Zürich, IT Services
+ * 
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+using CefSharp;
+
+namespace SafeExamBrowser.Browser.Wrapper.Events
+{
+	internal delegate void SetFocusEventHandler(IWebBrowser webBrowser, IBrowser browser, CefFocusSource source, GenericEventArgs args);
+}

SafeExamBrowser.Browser/Wrapper/Events/TakeFocusEventHandler.cs

@@ -0,0 +1,14 @@
+/*
+ * Copyright (c) 2024 ETH Zürich, IT Services
+ * 
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+using CefSharp;
+
+namespace SafeExamBrowser.Browser.Wrapper.Events
+{
+	internal delegate void TakeFocusEventHandler(IWebBrowser chromiumWebBrowser, IBrowser browser, bool next);
+}

SafeExamBrowser.Browser/Wrapper/Handlers/FocusHandlerSwitch.cs

@@ -0,0 +1,70 @@
+/*
+ * Copyright (c) 2024 ETH Zürich, IT Services
+ * 
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+using CefSharp;
+using CefSharp.WinForms;
+using CefSharp.WinForms.Host;
+using SafeExamBrowser.Browser.Wrapper.Events;
+
+namespace SafeExamBrowser.Browser.Wrapper.Handlers
+{
+	internal class FocusHandlerSwitch : IFocusHandler
+	{
+		public void OnGotFocus(IWebBrowser webBrowser, IBrowser browser)
+		{
+			if (browser.IsPopup)
+			{
+				var control = ChromiumHostControl.FromBrowser(browser) as CefSharpPopupControl;
+
+				control?.OnGotFocus(webBrowser, browser);
+			}
+			else
+			{
+				var control = ChromiumWebBrowser.FromBrowser(browser) as CefSharpBrowserControl;
+
+				control?.OnGotFocus(webBrowser, browser);
+			}
+		}
+
+		public bool OnSetFocus(IWebBrowser webBrowser, IBrowser browser, CefFocusSource source)
+		{
+			var args = new GenericEventArgs { Value = false };
+
+			if (browser.IsPopup)
+			{
+				var control = ChromiumHostControl.FromBrowser(browser) as CefSharpPopupControl;
+
+				control?.OnSetFocus(webBrowser, browser, source, args);
+			}
+			else
+			{
+				var control = ChromiumWebBrowser.FromBrowser(browser) as CefSharpBrowserControl;
+
+				control?.OnSetFocus(webBrowser, browser, source, args);
+			}
+
+			return args.Value;
+		}
+
+		public void OnTakeFocus(IWebBrowser webBrowser, IBrowser browser, bool next)
+		{
+			if (browser.IsPopup)
+			{
+				var control = ChromiumHostControl.FromBrowser(browser) as CefSharpPopupControl;
+
+				control?.OnTakeFocus(webBrowser, browser, next);
+			}
+			else
+			{
+				var control = ChromiumWebBrowser.FromBrowser(browser) as CefSharpBrowserControl;
+
+				control?.OnTakeFocus(webBrowser, browser, next);
+			}
+		}
+	}
+}

SafeExamBrowser.Browser/Wrapper/ICefSharpControl.cs

@@ -28,11 +28,14 @@ internal interface ICefSharpControl : IChromiumWebBrowserBase, IWinFormsChromium
 		event FaviconUrlChangedEventHandler FaviconUrlChanged;
 		event FileDialogRequestedEventHandler FileDialogRequested;
 		event FocusedNodeChangedEventHandler FocusedNodeChanged;
+		event GotFocusEventHandler GotFocusCefSharp;
 		event KeyEventHandler KeyEvent;
 		event LoadingProgressChangedEventHandler LoadingProgressChanged;
 		event OpenUrlFromTabEventHandler OpenUrlFromTab;
 		event PreKeyEventHandler PreKeyEvent;
 		event ResourceRequestEventHandler ResourceRequestHandlerRequired;
+		event SetFocusEventHandler SetFocus;
+		event TakeFocusEventHandler TakeFocus;
 		event UncaughtExceptionEventHandler UncaughtExceptionEvent;
 
 		void Dispose(bool disposing);
@@ -48,10 +51,13 @@ internal interface ICefSharpControl : IChromiumWebBrowserBase, IWinFormsChromium
 		void OnFaviconUrlChange(IWebBrowser webBrowser, IBrowser browser, IList<string> urls);
 		void OnFileDialog(IWebBrowser webBrowser, IBrowser browser, CefFileDialogMode mode, string title, string defaultFilePath, IReadOnlyCollection<string> acceptFilters, IReadOnlyCollection<string> acceptExtensions, IReadOnlyCollection<string> acceptDescriptions, IFileDialogCallback callback);
 		void OnFocusedNodeChanged(IWebBrowser webBrowser, IBrowser browser, IFrame frame, IDomNode node);
+		void OnGotFocus(IWebBrowser webBrowser, IBrowser browser);
 		void OnKeyEvent(IWebBrowser webBrowser, IBrowser browser, KeyType type, int windowsKeyCode, int nativeKeyCode, CefEventFlags modifiers, bool isSystemKey);
 		void OnLoadingProgressChange(IWebBrowser webBrowser, IBrowser browser, double progress);
 		void OnOpenUrlFromTab(IWebBrowser webBrowser, IBrowser browser, IFrame frame, string targetUrl, WindowOpenDisposition targetDisposition, bool userGesture, GenericEventArgs args);
 		void OnPreKeyEvent(IWebBrowser webBrowser, IBrowser browser, KeyType type, int windowsKeyCode, int nativeKeyCode, CefEventFlags modifiers, bool isSystemKey, ref bool isKeyboardShortcut, GenericEventArgs args);
+		void OnSetFocus(IWebBrowser webBrowser, IBrowser browser, CefFocusSource source, GenericEventArgs args);
+		void OnTakeFocus(IWebBrowser webBrowser, IBrowser browser, bool next);
 		void OnUncaughtException(IWebBrowser webBrowser, IBrowser browser, IFrame frame, JavascriptException exception);
 	}
 }