Started working on window monitoring.

SafeExamBrowser.Contracts/Monitoring/IWindowMonitor.cs

@@ -10,5 +10,25 @@ namespace SafeExamBrowser.Contracts.Monitoring
 {
 	public interface IWindowMonitor
 	{
+		/// <summary>
+		/// Hides all currently opened windows.
+		/// </summary>
+		void HideAllWindows();
+
+		/// <summary>
+		/// Restores all windows which were hidden during the startup procedure.
+		/// </summary>
+		void RestoreHiddenWindows();
+
+		/// <summary>
+		/// Starts monitoring application windows by subscribing to specific system events.
+		/// If a window is shown which is not supposed to do so, it will be automatically hidden.
+		/// </summary>
+		void StartMonitoringWindows();
+
+		/// <summary>
+		/// Stops monitoring windows and deregisters from any subscribed system events.
+		/// </summary>
+		void StopMonitoringWindows();
 	}
 }

SafeExamBrowser.Core/Behaviour/Operations/ProcessMonitoringOperation.cs

@@ -30,6 +30,11 @@ namespace SafeExamBrowser.Core.Behaviour.Operations
 		public void Perform()
 		{
 			logger.Info("--- Initializing process monitoring ---");
+			SplashScreen.UpdateText(Key.SplashScreen_WaitExplorerTermination, true);
+
+			processMonitor.CloseExplorerShell();
+			processMonitor.StartMonitoringExplorer();
+
 			SplashScreen.UpdateText(Key.SplashScreen_InitializeProcessMonitoring);
 
 			// TODO
@@ -41,6 +46,11 @@ namespace SafeExamBrowser.Core.Behaviour.Operations
 			SplashScreen.UpdateText(Key.SplashScreen_StopProcessMonitoring);
 
 			// TODO
+
+			SplashScreen.UpdateText(Key.SplashScreen_WaitExplorerStartup, true);
+
+			processMonitor.StopMonitoringExplorer();
+			processMonitor.StartExplorerShell();
 		}
 	}
 }

SafeExamBrowser.Core/Behaviour/Operations/WorkingAreaOperation.cs

@@ -10,7 +10,6 @@ using SafeExamBrowser.Contracts.Behaviour;
 using SafeExamBrowser.Contracts.Configuration;
 using SafeExamBrowser.Contracts.I18n;
 using SafeExamBrowser.Contracts.Logging;
-using SafeExamBrowser.Contracts.Monitoring;
 using SafeExamBrowser.Contracts.UserInterface;
 
 namespace SafeExamBrowser.Core.Behaviour.Operations
@@ -18,16 +17,14 @@ namespace SafeExamBrowser.Core.Behaviour.Operations
 	public class WorkingAreaOperation : IOperation
 	{
 		private ILogger logger;
-		private IProcessMonitor processMonitor;
 		private ITaskbar taskbar;
 		private IWorkingArea workingArea;
 
 		public ISplashScreen SplashScreen { private get; set; }
 
-		public WorkingAreaOperation(ILogger logger, IProcessMonitor processMonitor, ITaskbar taskbar, IWorkingArea workingArea)
+		public WorkingAreaOperation(ILogger logger, ITaskbar taskbar, IWorkingArea workingArea)
 		{
 			this.logger = logger;
-			this.processMonitor = processMonitor;
 			this.taskbar = taskbar;
 			this.workingArea = workingArea;
 		}
@@ -35,16 +32,11 @@ namespace SafeExamBrowser.Core.Behaviour.Operations
 		public void Perform()
 		{
 			logger.Info("--- Initializing working area ---");
-			SplashScreen.UpdateText(Key.SplashScreen_WaitExplorerTermination, true);
+			SplashScreen.UpdateText(Key.SplashScreen_InitializeWorkingArea);
-
-			processMonitor.CloseExplorerShell();
-			processMonitor.StartMonitoringExplorer();
 
 			// TODO
-			// - Minimizing all open windows
 			// - Emptying clipboard
 
-			SplashScreen.UpdateText(Key.SplashScreen_InitializeWorkingArea);
 			workingArea.InitializeFor(taskbar);
 		}
 
@@ -54,15 +46,9 @@ namespace SafeExamBrowser.Core.Behaviour.Operations
 			SplashScreen.UpdateText(Key.SplashScreen_RestoreWorkingArea);
 
 			// TODO
-			// - Restore all windows?
 			// - Emptying clipboard
 
 			workingArea.Reset();
-
-			SplashScreen.UpdateText(Key.SplashScreen_WaitExplorerStartup, true);
-
-			processMonitor.StopMonitoringExplorer();
-			processMonitor.StartExplorerShell();
 		}
 	}
 }

SafeExamBrowser.Monitoring/SafeExamBrowser.Monitoring.csproj

@@ -42,6 +42,7 @@
   <ItemGroup>
     <Compile Include="Processes\ProcessMonitor.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />
+    <Compile Include="Windows\WindowMonitor.cs" />
   </ItemGroup>
   <ItemGroup>
     <ProjectReference Include="..\SafeExamBrowser.Contracts\SafeExamBrowser.Contracts.csproj">
@@ -56,7 +57,6 @@
   <ItemGroup>
     <Folder Include="Keyboard\" />
     <Folder Include="Mouse\" />
-    <Folder Include="Windows\" />
   </ItemGroup>
   <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
 </Project>

SafeExamBrowser.Monitoring/Windows/WindowMonitor.cs

@@ -0,0 +1,50 @@
+/*
+ * Copyright (c) 2017 ETH Zürich, Educational Development and Technology (LET)
+ * 
+ * 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 System;
+using SafeExamBrowser.Contracts.Logging;
+using SafeExamBrowser.Contracts.Monitoring;
+using SafeExamBrowser.WindowsApi;
+
+namespace SafeExamBrowser.Monitoring.Windows
+{
+	public class WindowMonitor : IWindowMonitor
+	{
+		private ILogger logger;
+
+		public WindowMonitor(ILogger logger)
+		{
+			this.logger = logger;
+
+			// TODO: Make operation for window monitor OR operation for all desktop initialization?!
+			// ...
+		}
+
+		public void HideAllWindows()
+		{
+			logger.Info("Minimizing all open windows...");
+			User32.MinimizeAllOpenWindows();
+			logger.Info("Open windows successfully minimized.");
+		}
+
+		public void RestoreHiddenWindows()
+		{
+			throw new NotImplementedException();
+		}
+
+		public void StartMonitoringWindows()
+		{
+			throw new NotImplementedException();
+		}
+
+		public void StopMonitoringWindows()
+		{
+			throw new NotImplementedException();
+		}
+	}
+}

SafeExamBrowser.WindowsApi/Constants/Constant.cs

@@ -0,0 +1,16 @@
+/*
+ * Copyright (c) 2017 ETH Zürich, Educational Development and Technology (LET)
+ * 
+ * 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/.
+ */
+
+namespace SafeExamBrowser.WindowsApi.Constants
+{
+	static class Constant
+	{
+		internal const int WM_COMMAND = 0x111;
+		internal const int MIN_ALL = 419;
+	}
+}

SafeExamBrowser.WindowsApi/SafeExamBrowser.WindowsApi.csproj

@@ -40,6 +40,7 @@
     <Reference Include="System.Xml" />
   </ItemGroup>
   <ItemGroup>
+    <Compile Include="Constants\Constant.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />
     <Compile Include="Constants\SPI.cs" />
     <Compile Include="Constants\SPIF.cs" />

SafeExamBrowser.WindowsApi/User32.cs

@@ -35,7 +35,7 @@ namespace SafeExamBrowser.WindowsApi
 		/// <returns></returns>
 		public static uint GetShellProcessId()
 		{
-			var handle = FindWindow("Shell_TrayWnd", null);
+			var handle = GetShellWindowHandle();
 			var threadId = GetWindowThreadProcessId(handle, out uint processId);
 
 			return processId;
@@ -60,6 +60,16 @@ namespace SafeExamBrowser.WindowsApi
 			return workingArea;
 		}
 
+		/// <summary>
+		/// Minimizes all open windows.
+		/// </summary>
+		public static void MinimizeAllOpenWindows()
+		{
+			var handle = GetShellWindowHandle();
+
+			SendMessage(handle, Constant.WM_COMMAND, (IntPtr) Constant.MIN_ALL, IntPtr.Zero);
+		}
+
 		/// <summary>
 		/// Instructs the main Windows explorer process to shut down.
 		/// </summary>
@@ -72,8 +82,8 @@ namespace SafeExamBrowser.WindowsApi
 		/// </remarks>
 		public static void PostCloseMessageToShell()
 		{
-			var taskbarHandle = FindWindow("Shell_TrayWnd", null);
+			var handle = GetShellWindowHandle();
-			var success = PostMessage(taskbarHandle, 0x5B4, IntPtr.Zero, IntPtr.Zero);
+			var success = PostMessage(handle, 0x5B4, IntPtr.Zero, IntPtr.Zero);
 
 			if (!success)
 			{
@@ -107,6 +117,9 @@ namespace SafeExamBrowser.WindowsApi
 		[return: MarshalAs(UnmanagedType.Bool)]
 		private static extern bool PostMessage(IntPtr hWnd, uint msg, IntPtr wParam, IntPtr lParam);
 
+		[DllImport("user32.dll", EntryPoint = "SendMessage")]
+		private static extern IntPtr SendMessage(IntPtr hWnd, uint msg, IntPtr wParam, IntPtr lParam);
+
 		[DllImport("user32.dll", SetLastError = true)]
 		[return: MarshalAs(UnmanagedType.Bool)]
 		static extern bool SystemParametersInfo(SPI uiAction, uint uiParam, ref RECT pvParam, SPIF fWinIni);

SafeExamBrowser/CompositionRoot.cs

@@ -20,6 +20,7 @@ using SafeExamBrowser.Core.Behaviour.Operations;
 using SafeExamBrowser.Core.I18n;
 using SafeExamBrowser.Core.Logging;
 using SafeExamBrowser.Monitoring.Processes;
+using SafeExamBrowser.Monitoring.Windows;
 using SafeExamBrowser.UserInterface;
 
 namespace SafeExamBrowser
@@ -36,6 +37,7 @@ namespace SafeExamBrowser
 		private IText text;
 		private ITextResource textResource;
 		private IUiElementFactory uiFactory;
+		private IWindowMonitor windowMonitor;
 		private IWorkingArea workingArea;
 
 		public IShutdownController ShutdownController { get; private set; }
@@ -59,13 +61,14 @@ namespace SafeExamBrowser
 			text = new Text(textResource);
 			aboutInfo = new AboutNotificationInfo(text);
 			processMonitor = new ProcessMonitor(new ModuleLogger(logger, typeof(ProcessMonitor)));
+			windowMonitor = new WindowMonitor(new ModuleLogger(logger, typeof(WindowMonitor)));
 			workingArea = new WorkingArea(new ModuleLogger(logger, typeof(WorkingArea)));
 			ShutdownController = new ShutdownController(logger, messageBox, processMonitor, settings, text, uiFactory, workingArea);
 			StartupController = new StartupController(browserController, browserInfo, logger, messageBox, aboutInfo, processMonitor, settings, Taskbar, text, uiFactory, workingArea);
 
 			StartupOperations = new Queue<IOperation>();
 			StartupOperations.Enqueue(new ProcessMonitoringOperation(logger, processMonitor));
-			StartupOperations.Enqueue(new WorkingAreaOperation(logger, processMonitor, Taskbar, workingArea));
+			StartupOperations.Enqueue(new WorkingAreaOperation(logger, Taskbar, workingArea));
 			StartupOperations.Enqueue(new TaskbarInitializationOperation(logger, aboutInfo, Taskbar, uiFactory));
 			StartupOperations.Enqueue(new BrowserInitializationOperation(browserController, browserInfo, logger, Taskbar, uiFactory));
 		}