Restore SEBPatch

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

@@ -0,0 +1,197 @@
+/*
+ * 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 System;
+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.Taskview;
+
+namespace SafeExamBrowser.UserInterface.Mobile.Windows
+{
+	internal partial class Taskview : Window, ITaskview
+	{
+		private readonly IList<IApplication<IApplicationWindow>> applications;
+		private readonly LinkedList<WindowControl> controls;
+
+		private LinkedListNode<WindowControl> current;
+
+		internal IntPtr Handle { get; private set; }
+
+		internal Taskview()
+		{
+			applications = new List<IApplication<IApplicationWindow>>();
+			controls = new LinkedList<WindowControl>();
+
+			InitializeComponent();
+			InitializeTaskview();
+		}
+
+		public void Add(IApplication<IApplicationWindow> application)
+		{
+			application.WindowsChanged += Application_WindowsChanged;
+			applications.Add(application);
+		}
+
+		public void Register(ITaskviewActivator activator)
+		{
+			activator.Deactivated += Activator_Deactivated;
+			activator.NextActivated += Activator_Next;
+			activator.PreviousActivated += Activator_Previous;
+		}
+
+		private void Application_WindowsChanged()
+		{
+			Dispatcher.InvokeAsync(Update);
+		}
+
+		private void Activator_Deactivated()
+		{
+			Dispatcher.InvokeAsync(ActivateAndHide);
+		}
+
+		private void Activator_Next()
+		{
+			Dispatcher.InvokeAsync(SelectNext);
+		}
+
+		private void Activator_Previous()
+		{
+			Dispatcher.InvokeAsync(SelectPrevious);
+		}
+
+		private void ActivateAndHide()
+		{
+			if (IsVisible)
+			{
+				Activate();
+				current?.Value.Activate();
+				Hide();
+			}
+		}
+
+		private void InitializeTaskview()
+		{
+			Loaded += (o, args) =>
+			{
+				Handle = new WindowInteropHelper(this).Handle;
+				Update();
+			};
+		}
+
+		private void SelectNext()
+		{
+			ShowConditional();
+
+			if (current != null)
+			{
+				current.Value.Deselect();
+				current = current.Next ?? controls.First;
+				current.Value.Select();
+			}
+		}
+
+		private void SelectPrevious()
+		{
+			ShowConditional();
+
+			if (current != null)
+			{
+				current.Value.Deselect();
+				current = current.Previous ?? controls.Last;
+				current.Value.Select();
+			}
+		}
+
+		private void ShowConditional()
+		{
+			if (controls.Any() && Visibility != Visibility.Visible)
+			{
+				Show();
+				Activate();
+			}
+		}
+
+		private void Update()
+		{
+			ClearTaskview();
+			LoadControls();
+			UpdateLocation();
+		}
+
+		private void ClearTaskview()
+		{
+			foreach (var control in controls)
+			{
+				control.Destroy();
+			}
+
+			controls.Clear();
+			Rows.Children.Clear();
+		}
+
+		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 column = 0; column < maxColumns && windows.Any(); column++)
+				{
+					var window = windows.Pop();
+					var control = new WindowControl(window, this);
+
+					controls.AddLast(control);
+					row.Children.Add(control);
+				}
+			}
+
+			current = controls.First;
+			current?.Value.Select();
+		}
+
+		private void UpdateLocation()
+		{
+			if (controls.Any())
+			{
+				UpdateLayout();
+
+				Left = (SystemParameters.WorkArea.Width - Width) / 2 + SystemParameters.WorkArea.Left;
+				Top = (SystemParameters.WorkArea.Height - Height) / 2 + SystemParameters.WorkArea.Top;
+			}
+			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;
+		}
+	}
+}