SEBWIN-312: Implemented thumbnails of open windows for mobile taskview.

SafeExamBrowser.Client/CompositionRoot.cs

@@ -309,7 +309,7 @@ namespace SafeExamBrowser.Client
 			switch (uiMode)
 			{
 				case UserInterfaceMode.Mobile:
-					return new Mobile.TaskView();
+					return new Mobile.Taskview();
 				default:
 					return new Desktop.Taskview();
 			}

SafeExamBrowser.UserInterface.Mobile/Controls/TaskViewWindowControl.xaml

@@ -1,9 +1,10 @@
-<UserControl x:Class="SafeExamBrowser.UserInterface.Mobile.Controls.TaskViewWindowControl"
+<UserControl x:Class="SafeExamBrowser.UserInterface.Mobile.Controls.TaskviewWindowControl"
              xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
              xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
              xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
              xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
-             xmlns:local="clr-namespace:SafeExamBrowser.UserInterface.Mobile.Controls">
+             xmlns:local="clr-namespace:SafeExamBrowser.UserInterface.Mobile.Controls"
+             FontSize="16">
     <UserControl.Resources>
         <ResourceDictionary>
             <ResourceDictionary.MergedDictionaries>
@@ -11,11 +12,20 @@
             </ResourceDictionary.MergedDictionaries>
         </ResourceDictionary>
     </UserControl.Resources>
-    <Grid Margin="5" Height="150" Width="250">
+    <Grid Margin="5" Height="200" Width="300">
         <Border Name="Indicator" Background="{StaticResource BackgroundTransparentEmphasisBrush}" BorderThickness="0" Visibility="Hidden" />
-        <StackPanel HorizontalAlignment="Center" Orientation="Vertical" VerticalAlignment="Center">
+        <Grid Margin="5">
-            <ContentControl Name="Icon" MaxWidth="40" />
+            <Grid.ColumnDefinitions>
-            <TextBlock Name="Title" Margin="10" Foreground="{StaticResource PrimaryTextBrush}" TextTrimming="CharacterEllipsis" />
+                <ColumnDefinition Width="Auto" />
-        </StackPanel>
+                <ColumnDefinition Width="*" />
+            </Grid.ColumnDefinitions>
+            <Grid.RowDefinitions>
+                <RowDefinition Height="Auto" />
+                <RowDefinition Height="*" />
+            </Grid.RowDefinitions>
+            <ContentControl Grid.Row="0" Grid.Column="0" Name="Icon" Margin="0,0,5,0" Height="24" />
+            <TextBlock Grid.Row="0" Grid.Column="1" Name="Title" Foreground="{StaticResource PrimaryTextBrush}" VerticalAlignment="Center" TextTrimming="CharacterEllipsis" />
+            <ContentControl Grid.Row="1" Grid.ColumnSpan="2" Name="Placeholder" Margin="0,5,0,0" />
+        </Grid>
     </Grid>
 </UserControl>

SafeExamBrowser.UserInterface.Mobile/Controls/TaskViewWindowControl.xaml.cs

@@ -6,6 +6,7 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
  */
 
+using System;
 using System.Windows;
 using System.Windows.Controls;
 using SafeExamBrowser.Applications.Contracts;
@@ -14,13 +15,16 @@ using SafeExamBrowser.UserInterface.Shared.Utilities;
 
 namespace SafeExamBrowser.UserInterface.Mobile.Controls
 {
-	public partial class TaskViewWindowControl : UserControl
+	public partial class TaskviewWindowControl : UserControl
 	{
+		private Taskview taskview;
+		private IntPtr thumbnail;
 		private IApplicationWindow window;
 
-		public TaskViewWindowControl(IApplicationWindow window)
+		public TaskviewWindowControl(IApplicationWindow window, Taskview taskview)
 		{
 			this.window = window;
+			this.taskview = taskview;
 
 			InitializeComponent();
 			InitializeControl();
@@ -33,35 +37,128 @@ namespace SafeExamBrowser.UserInterface.Mobile.Controls
 
 		internal void Deselect()
 		{
-			Icon.MaxWidth = 40;
 			Indicator.Visibility = Visibility.Hidden;
 			Title.FontWeight = FontWeights.Normal;
 		}
 
+		internal void Destroy()
+		{
+			if (thumbnail != IntPtr.Zero)
+			{
+				Thumbnail.DwmUnregisterThumbnail(thumbnail);
+			}
+		}
+
 		internal void Select()
 		{
-			Icon.MaxWidth = 50;
 			Indicator.Visibility = Visibility.Visible;
 			Title.FontWeight = FontWeights.SemiBold;
 		}
 
+		internal void Update()
+		{
+			if (!IsLoaded || !IsVisible)
+			{
+				return;
+			}
+
+			if (thumbnail == IntPtr.Zero && taskview.Handle != IntPtr.Zero && window.Handle != IntPtr.Zero)
+			{
+				Thumbnail.DwmRegisterThumbnail(taskview.Handle, window.Handle, out thumbnail);
+			}
+
+			if (thumbnail != IntPtr.Zero)
+			{
+				Thumbnail.DwmQueryThumbnailSourceSize(thumbnail, out var size);
+
+				var destination = CalculatePhysicalDestination(size);
+				var properties = new Thumbnail.Properties
+				{
+					Destination = destination,
+					Flags = Thumbnail.DWM_TNP_RECTDESTINATION | Thumbnail.DWM_TNP_VISIBLE,
+					Visible = true
+				};
+
+				Thumbnail.DwmUpdateThumbnailProperties(thumbnail, ref properties);
+			}
+		}
+
+		private void TaskViewWindowControl_IsVisibleChanged(object sender, DependencyPropertyChangedEventArgs e)
+		{
+			if (e.NewValue as bool? == true)
+			{
+				Update();
+			}
+		}
+
+		private void Window_TitleChanged(string title)
+		{
+			Dispatcher.InvokeAsync(() => Title.Text = title);
+		}
+
+		private void Window_IconChanged(IconResource icon)
+		{
+			Dispatcher.InvokeAsync(() => Icon.Content = IconResourceLoader.Load(window.Icon));
+		}
+
+		private Thumbnail.Rectangle CalculatePhysicalDestination(Thumbnail.Size size)
+		{
+			var controlToTaskview = TransformToVisual(taskview);
+			var placeholderToControl = Placeholder.TransformToVisual(this);
+			var placeholderLeft = placeholderToControl.Transform(new Point(0, 0)).X;
+			var placeholderTop = placeholderToControl.Transform(new Point(0, 0)).Y;
+			var placeholderRight = placeholderToControl.Transform(new Point(Placeholder.ActualWidth, 0)).X;
+			var placeholderBottom = placeholderToControl.Transform(new Point(0, Placeholder.ActualHeight)).Y;
+
+			var physicalBounds = new Thumbnail.Rectangle
+			{
+				Left = (int) Math.Round(this.TransformToPhysical(controlToTaskview.Transform(new Point(placeholderLeft, 0)).X, 0).X),
+				Top = (int) Math.Round(this.TransformToPhysical(0, controlToTaskview.Transform(new Point(0, placeholderTop)).Y).Y),
+				Right = (int) Math.Round(this.TransformToPhysical(controlToTaskview.Transform(new Point(placeholderRight, 0)).X, 0).X),
+				Bottom = (int) Math.Round(this.TransformToPhysical(0, controlToTaskview.Transform(new Point(0, placeholderBottom)).Y).Y)
+			};
+
+			var scaleFactor = default(double);
+			var thumbnailHeight = default(double);
+			var thumbnailWidth = default(double);
+			var maxWidth = (double) physicalBounds.Right - physicalBounds.Left;
+			var maxHeight = (double) physicalBounds.Bottom - physicalBounds.Top;
+			var placeholderRatio = maxWidth / maxHeight;
+			var windowRatio = (double) size.X / size.Y;
+
+			if (windowRatio < placeholderRatio)
+			{
+				thumbnailHeight = maxHeight;
+				scaleFactor = thumbnailHeight / size.Y;
+				thumbnailWidth = size.X * scaleFactor;
+			}
+			else
+			{
+				thumbnailWidth = maxWidth;
+				scaleFactor = thumbnailWidth / size.X;
+				thumbnailHeight = size.Y * scaleFactor;
+			}
+
+			var widthDifference = maxWidth - thumbnailWidth;
+			var heightDifference = maxHeight - thumbnailHeight;
+
+			return new Thumbnail.Rectangle
+			{
+				Left = (int) Math.Round(physicalBounds.Left + (widthDifference / 2)),
+				Top = (int) Math.Round(physicalBounds.Top + (heightDifference / 2)),
+				Right = (int) Math.Round(physicalBounds.Right - (widthDifference / 2)),
+				Bottom = (int) Math.Round(physicalBounds.Bottom - (heightDifference / 2))
+			};
+		}
+
 		private void InitializeControl()
 		{
 			Icon.Content = IconResourceLoader.Load(window.Icon);
+			IsVisibleChanged += TaskViewWindowControl_IsVisibleChanged;
+			Loaded += (o, args) => Update();
 			Title.Text = window.Title;
-
+			window.IconChanged += Window_IconChanged;
-			window.IconChanged += Instance_IconChanged;
+			window.TitleChanged += Window_TitleChanged;
-			window.TitleChanged += Instance_TitleChanged;
-		}
-
-		private void Instance_TitleChanged(string title)
-		{
-			Dispatcher.InvokeAsync(() => Title.Text = title);
-		}
-
-		private void Instance_IconChanged(IconResource icon)
-		{
-			Dispatcher.InvokeAsync(() => Icon.Content = IconResourceLoader.Load(window.Icon));
 		}
 	}
 }

SafeExamBrowser.UserInterface.Mobile/SafeExamBrowser.UserInterface.Mobile.csproj

@@ -143,8 +143,8 @@
     <Compile Include="Controls\TaskbarWirelessNetworkControl.xaml.cs">
       <DependentUpon>TaskbarWirelessNetworkControl.xaml</DependentUpon>
     </Compile>
-    <Compile Include="Controls\TaskViewWindowControl.xaml.cs">
+    <Compile Include="Controls\TaskviewWindowControl.xaml.cs">
-      <DependentUpon>TaskViewWindowControl.xaml</DependentUpon>
+      <DependentUpon>TaskviewWindowControl.xaml</DependentUpon>
     </Compile>
     <Compile Include="LockScreen.xaml.cs">
       <DependentUpon>LockScreen.xaml</DependentUpon>
@@ -171,8 +171,8 @@
     <Compile Include="Taskbar.xaml.cs">
       <DependentUpon>Taskbar.xaml</DependentUpon>
     </Compile>
-    <Compile Include="TaskView.xaml.cs">
+    <Compile Include="Taskview.xaml.cs">
-      <DependentUpon>TaskView.xaml</DependentUpon>
+      <DependentUpon>Taskview.xaml</DependentUpon>
     </Compile>
     <Compile Include="UserInterfaceFactory.cs" />
     <Compile Include="ViewModels\DateTimeViewModel.cs" />
@@ -355,7 +355,7 @@
       <Generator>MSBuild:Compile</Generator>
       <SubType>Designer</SubType>
     </Resource>
-    <Page Include="Controls\TaskViewWindowControl.xaml">
+    <Page Include="Controls\TaskviewWindowControl.xaml">
       <Generator>MSBuild:Compile</Generator>
       <SubType>Designer</SubType>
     </Page>
@@ -463,7 +463,7 @@
       <Generator>MSBuild:Compile</Generator>
       <SubType>Designer</SubType>
     </Page>
-    <Page Include="TaskView.xaml">
+    <Page Include="Taskview.xaml">
       <Generator>MSBuild:Compile</Generator>
       <SubType>Designer</SubType>
     </Page>

SafeExamBrowser.UserInterface.Mobile/TaskView.xaml

@@ -1,11 +1,11 @@
-<Window x:Class="SafeExamBrowser.UserInterface.Mobile.TaskView"
+<Window x:Class="SafeExamBrowser.UserInterface.Mobile.Taskview"
         xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
         xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
         xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
         xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
         xmlns:local="clr-namespace:SafeExamBrowser.UserInterface.Mobile"
         mc:Ignorable="d" AllowsTransparency="True" Background="{DynamicResource BackgroundTransparentBrush}" BorderBrush="DodgerBlue" BorderThickness="1"
-        Title="TaskView" Topmost="True" Height="450" SizeToContent="WidthAndHeight" Width="800" WindowStartupLocation="CenterScreen" WindowStyle="None">
+        Title="Taskview" Topmost="True" Height="450" SizeToContent="WidthAndHeight" Width="800" WindowStartupLocation="CenterScreen" WindowStyle="None">
     <Window.Resources>
         <ResourceDictionary>
             <ResourceDictionary.MergedDictionaries>

SafeExamBrowser.UserInterface.Mobile/TaskView.xaml.cs

@@ -11,24 +11,28 @@ using System.Collections.Generic;
 using System.Linq;
 using System.Windows;
 using System.Windows.Controls;
+using System.Windows.Interop;
 using SafeExamBrowser.Applications.Contracts;
 using SafeExamBrowser.UserInterface.Contracts.Shell;
 using SafeExamBrowser.UserInterface.Mobile.Controls;
 
 namespace SafeExamBrowser.UserInterface.Mobile
 {
-	public partial class TaskView : Window, ITaskView
+	public partial class Taskview : Window, ITaskView
 	{
 		private IList<IApplication> applications;
-		private LinkedListNode<TaskViewWindowControl> current;
+		private LinkedListNode<TaskviewWindowControl> current;
-		private LinkedList<TaskViewWindowControl> controls;
+		private LinkedList<TaskviewWindowControl> controls;
 
-		public TaskView()
+		internal IntPtr Handle { get; private set; }
+
+		public Taskview()
 		{
 			applications = new List<IApplication>();
-			controls = new LinkedList<TaskViewWindowControl>();
+			controls = new LinkedList<TaskviewWindowControl>();
 
 			InitializeComponent();
+			InitializeTaskview();
 		}
 
 		public void Add(IApplication application)
@@ -66,9 +70,21 @@ namespace SafeExamBrowser.UserInterface.Mobile
 
 		private void ActivateAndHide()
 		{
-			Activate();
+			if (IsVisible)
-			current?.Value.Activate();
+			{
-			Hide();
+				Activate();
+				current?.Value.Activate();
+				Hide();
+			}
+		}
+
+		private void InitializeTaskview()
+		{
+			Loaded += (o, args) =>
+			{
+				Handle = new WindowInteropHelper(this).Handle;
+				Update();
+			};
 		}
 
 		private void SelectNext()
@@ -106,31 +122,37 @@ namespace SafeExamBrowser.UserInterface.Mobile
 
 		private void Update()
 		{
-			var windows = new Stack<IApplicationWindow>();
+			ClearTaskview();
+			LoadControls();
+			UpdateLocation();
+		}
 
-			foreach (var application in applications)
+		private void ClearTaskview()
+		{
+			foreach (var control in controls)
 			{
-				foreach (var window in application.GetWindows())
+				control.Destroy();
-				{
-					windows.Push(window);
-				}
 			}
 
-			var max = Math.Ceiling(Math.Sqrt(windows.Count));
-
 			controls.Clear();
 			Rows.Children.Clear();
+		}
 
-			for (var rowCount = 0; rowCount < max && windows.Any(); rowCount++)
+		private void LoadControls()
+		{
+			var windows = GetAllWindows();
+			var maxColumns = Math.Ceiling(Math.Sqrt(windows.Count));
+
+			while (windows.Any())
 			{
 				var row = new StackPanel { Orientation = Orientation.Horizontal, HorizontalAlignment = HorizontalAlignment.Center };
 
 				Rows.Children.Add(row);
 
-				for (var columnIndex = 0; columnIndex < max && windows.Any(); columnIndex++)
+				for (var column = 0; column < maxColumns && windows.Any(); column++)
 				{
 					var window = windows.Pop();
-					var control = new TaskViewWindowControl(window);
+					var control = new TaskviewWindowControl(window, this);
 
 					controls.AddLast(control);
 					row.Children.Add(control);
@@ -139,16 +161,36 @@ namespace SafeExamBrowser.UserInterface.Mobile
 
 			current = controls.First;
 			current?.Value.Select();
+		}
 
-			UpdateLayout();
+		private void UpdateLocation()
+		{
+			if (controls.Any())
+			{
+				UpdateLayout();
 
-			Left = (SystemParameters.WorkArea.Width - Width) / 2 + SystemParameters.WorkArea.Left;
+				Left = (SystemParameters.WorkArea.Width - Width) / 2 + SystemParameters.WorkArea.Left;
-			Top = (SystemParameters.WorkArea.Height - Height) / 2 + SystemParameters.WorkArea.Top;
+				Top = (SystemParameters.WorkArea.Height - Height) / 2 + SystemParameters.WorkArea.Top;
-
+			}
-			if (!controls.Any())
+			else
 			{
 				Hide();
 			}
 		}
+
+		private Stack<IApplicationWindow> GetAllWindows()
+		{
+			var stack = new Stack<IApplicationWindow>();
+
+			foreach (var application in applications)
+			{
+				foreach (var window in application.GetWindows())
+				{
+					stack.Push(window);
+				}
+			}
+
+			return stack;
+		}
 	}
 }