SEBWIN-475: Fixed issue with Zoom client not starting microphone and webcam.

SafeExamBrowser.Configuration/ConfigurationData/DataProcessor.cs

@@ -74,6 +74,11 @@ namespace SafeExamBrowser.Configuration.ConfigurationData
 			{
 				settings.Proctoring.WindowVisibility = WindowVisibility.Hidden;
 			}
+
+			if (settings.Proctoring.Zoom.Enabled && !settings.Proctoring.Zoom.ReceiveVideo)
+			{
+				settings.Proctoring.WindowVisibility = WindowVisibility.Hidden;
+			}
 		}
 
 		private void RemoveLegacyBrowsers(AppSettings settings)

SafeExamBrowser.Proctoring/ProctoringController.cs

@@ -185,7 +185,14 @@ namespace SafeExamBrowser.Proctoring
 
 					if (settings.WindowVisibility == WindowVisibility.AllowToShow || settings.WindowVisibility == WindowVisibility.Hidden)
 					{
-						window.Hide();
+						if (settings.Zoom.Enabled)
+						{
+							window.HideWithDelay();
+						}
+						else
+						{
+							window.Hide();
+						}
 					}
 
 					IconResource = new XamlIconResource { Uri = new Uri("pack://application:,,,/SafeExamBrowser.UserInterface.Desktop;component/Images/ProctoringNotification_Active.xaml") };

SafeExamBrowser.UserInterface.Contracts/Proctoring/IProctoringWindow.cs

@@ -15,6 +15,12 @@ namespace SafeExamBrowser.UserInterface.Contracts.Proctoring
 	/// </summary>
 	public interface IProctoringWindow : IWindow
 	{
+		/// <summary>
+		/// First moves the window to the background and then hides it after a timeout. This might be necessary to allow the meeting client to 
+		/// finish its initialization work and start the microphone as well as the camera before being hidden.
+		/// </summary>
+		void HideWithDelay();
+
 		/// <summary>
 		/// Sets the window title to the given value.
 		/// </summary>

SafeExamBrowser.UserInterface.Desktop/Windows/ProctoringWindow.xaml.cs

@@ -7,6 +7,7 @@
  */
 
 using System.ComponentModel;
+using System.Threading.Tasks;
 using System.Windows;
 using SafeExamBrowser.UserInterface.Contracts.Proctoring;
 using SafeExamBrowser.UserInterface.Contracts.Windows;
@@ -59,6 +60,12 @@ namespace SafeExamBrowser.UserInterface.Desktop.Windows
 			Dispatcher.Invoke(base.Hide);
 		}
 
+		public void HideWithDelay()
+		{
+			Dispatcher.Invoke(() => this.MoveToBackground());
+			Task.Delay(10000).ContinueWith(_ => Hide());
+		}
+
 		public void SetTitle(string title)
 		{
 			Dispatcher.Invoke(() => Title = title ?? "");

SafeExamBrowser.UserInterface.Mobile/Windows/ProctoringWindow.xaml.cs

@@ -7,6 +7,7 @@
  */
 
 using System.ComponentModel;
+using System.Threading.Tasks;
 using System.Windows;
 using SafeExamBrowser.UserInterface.Contracts.Proctoring;
 using SafeExamBrowser.UserInterface.Contracts.Windows;
@@ -59,6 +60,12 @@ namespace SafeExamBrowser.UserInterface.Mobile.Windows
 			Dispatcher.Invoke(base.Hide);
 		}
 
+		public void HideWithDelay()
+		{
+			Dispatcher.Invoke(() => this.MoveToBackground());
+			Task.Delay(10000).ContinueWith(_ => Hide());
+		}
+
 		public void SetTitle(string title)
 		{
 			Dispatcher.Invoke(() => Title = title ?? "");

SafeExamBrowser.UserInterface.Shared/Utilities/WindowExtensions.cs

@@ -20,8 +20,11 @@ namespace SafeExamBrowser.UserInterface.Shared.Utilities
 		private const uint MF_GRAYED = 0x00000001;
 		private const uint MF_ENABLED = 0x00000000;
 		private const uint SC_CLOSE = 0xF060;
+		private const uint SWP_SHOWWINDOW = 0x0040;
 		private const int WS_SYSMENU = 0x80000;
 
+		private static readonly IntPtr HWND_BOTTOM = new IntPtr(1);
+
 		public static void DisableCloseButton(this Window window)
 		{
 			var helper = new WindowInteropHelper(window);
@@ -41,6 +44,17 @@ namespace SafeExamBrowser.UserInterface.Shared.Utilities
 			SetWindowLong(helper.Handle, GWL_STYLE, style);
 		}
 
+		public static void MoveToBackground(this Window window)
+		{
+			var helper = new WindowInteropHelper(window);
+			var x = (int) window.TransformFromPhysical(window.Left, 0).X;
+			var y = (int) window.TransformFromPhysical(0, window.Top).Y;
+			var width = (int) window.TransformFromPhysical(window.Width, 0).X;
+			var height = (int) window.TransformFromPhysical(0, window.Height).Y;
+
+			SetWindowPos(helper.Handle, HWND_BOTTOM, x, y, width, height, SWP_SHOWWINDOW);
+		}
+
 		[DllImport("user32.dll")]
 		private static extern bool EnableMenuItem(IntPtr hMenu, uint uIDEnableItem, uint uEnable);
 
@@ -52,5 +66,8 @@ namespace SafeExamBrowser.UserInterface.Shared.Utilities
 
 		[DllImport("user32.dll")]
 		private static extern int SetWindowLong(IntPtr hWnd, int nIndex, int dwNewLong);
+
+		[DllImport("user32.dll")]
+		private static extern bool SetWindowPos(IntPtr hWnd, IntPtr hWndInsertAfter, int X, int Y, int cx, int cy, uint uFlags);
 	}
 }