Minor refactoring of taskbar (extracted code for physical pixel calculation and removed scroll wheel preview for ApplicationScrollViewer).

SafeExamBrowser.UserInterface/SafeExamBrowser.UserInterface.csproj

@@ -112,6 +112,7 @@
     </Compile>
     <Compile Include="UserInterfaceFactory.cs" />
     <Compile Include="Utilities\IconResourceLoader.cs" />
+    <Compile Include="Utilities\VisualExtensions.cs" />
     <Compile Include="ViewModels\DateTimeViewModel.cs" />
     <Compile Include="ViewModels\LogViewModel.cs" />
     <Compile Include="ViewModels\SplashScreenViewModel.cs" />

SafeExamBrowser.UserInterface/Taskbar.xaml

@@ -19,7 +19,7 @@
                 <ColumnDefinition Width="Auto" />
                 <ColumnDefinition Width="40" />
             </Grid.ColumnDefinitions>
-            <ScrollViewer Grid.Column="0" x:Name="ApplicationScrollViewer" VerticalScrollBarVisibility="Disabled" HorizontalScrollBarVisibility="Auto" PreviewMouseWheel="ApplicationScrollViewer_PreviewMouseWheel">
+            <ScrollViewer Grid.Column="0" x:Name="ApplicationScrollViewer" VerticalScrollBarVisibility="Disabled" HorizontalScrollBarVisibility="Auto">
                 <ScrollViewer.Resources>
                     <s:Double x:Key="{x:Static SystemParameters.HorizontalScrollBarHeightKey}">5</s:Double>
                 </ScrollViewer.Resources>

SafeExamBrowser.UserInterface/Taskbar.xaml.cs

@@ -7,11 +7,9 @@
  */
 
 using System.Windows;
-using System.Windows.Input;
-using System.Windows.Interop;
-using System.Windows.Media;
 using SafeExamBrowser.Contracts.Logging;
 using SafeExamBrowser.Contracts.UserInterface;
+using SafeExamBrowser.UserInterface.Utilities;
 
 namespace SafeExamBrowser.UserInterface
 {
@@ -48,7 +46,7 @@ namespace SafeExamBrowser.UserInterface
 		{
 			return Dispatcher.Invoke(() =>
 			{
-				var height = (int) TransformToPhysical(Width, Height).Y;
+				var height = (int) this.TransformToPhysical(Width, Height).Y;
 
 				logger.Info($"Calculated physical taskbar height is {height}px.");
 
@@ -64,66 +62,11 @@ namespace SafeExamBrowser.UserInterface
 				Left = SystemParameters.WorkArea.Right - Width;
 				Top = SystemParameters.WorkArea.Bottom;
 
-				var position = TransformToPhysical(Left, Top);
+				var position = this.TransformToPhysical(Left, Top);
-				var size = TransformToPhysical(Width, Height);
+				var size = this.TransformToPhysical(Width, Height);
 
 				logger.Info($"Set taskbar bounds to {Width}x{Height} at ({Left}/{Top}), in physical pixels: {size.X}x{size.Y} at ({position.X}/{position.Y}).");
 			});
 		}
-
-		private void ApplicationScrollViewer_PreviewMouseWheel(object sender, MouseWheelEventArgs e)
-		{
-			var scrollAmount = 20;
-
-			if (ApplicationScrollViewer.IsMouseOver)
-			{
-				if (e.Delta < 0)
-				{
-					if (ApplicationScrollViewer.HorizontalOffset + scrollAmount > 0)
-					{
-						ApplicationScrollViewer.ScrollToHorizontalOffset(ApplicationScrollViewer.HorizontalOffset + scrollAmount);
-					}
-					else
-					{
-						ApplicationScrollViewer.ScrollToLeftEnd();
-					}
-				}
-				else
-				{
-					if (ApplicationScrollViewer.ExtentWidth > ApplicationScrollViewer.HorizontalOffset - scrollAmount)
-					{
-						ApplicationScrollViewer.ScrollToHorizontalOffset(ApplicationScrollViewer.HorizontalOffset - scrollAmount);
-					}
-					else
-					{
-						ApplicationScrollViewer.ScrollToRightEnd();
-					}
-				}
-			}
-		}
-
-		private Vector TransformToPhysical(double x, double y)
-		{
-			// WPF works with device-independent pixels. The following code is required
-			// to transform those values to their absolute, device-specific pixel value.
-			// Source: https://stackoverflow.com/questions/3286175/how-do-i-convert-a-wpf-size-to-physical-pixels
-
-			Matrix transformToDevice;
-			var source = PresentationSource.FromVisual(this);
-
-			if (source != null)
-			{
-				transformToDevice = source.CompositionTarget.TransformToDevice;
-			}
-			else
-			{
-				using (var newSource = new HwndSource(new HwndSourceParameters()))
-				{
-					transformToDevice = newSource.CompositionTarget.TransformToDevice;
-				}
-			}
-
-			return transformToDevice.Transform(new Vector(x, y));
-		}
 	}
 }

SafeExamBrowser.UserInterface/Utilities/VisualExtensions.cs

@@ -0,0 +1,42 @@
+/*
+ * 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.Windows;
+using System.Windows.Interop;
+using System.Windows.Media;
+
+namespace SafeExamBrowser.UserInterface.Utilities
+{
+	internal static class VisualExtensions
+	{
+		/// <summary>
+		/// WPF works with device-independent pixels. This method is required to
+		/// transform such values to their absolute, device-specific pixel value.
+		/// Source: https://stackoverflow.com/questions/3286175/how-do-i-convert-a-wpf-size-to-physical-pixels
+		/// </summary>
+		internal static Vector TransformToPhysical(this Visual visual, double x, double y)
+		{
+			Matrix transformToDevice;
+			var source = PresentationSource.FromVisual(visual);
+
+			if (source != null)
+			{
+				transformToDevice = source.CompositionTarget.TransformToDevice;
+			}
+			else
+			{
+				using (var newSource = new HwndSource(new HwndSourceParameters()))
+				{
+					transformToDevice = newSource.CompositionTarget.TransformToDevice;
+				}
+			}
+
+			return transformToDevice.Transform(new Vector(x, y));
+		}
+	}
+}