Restore SEBPatch

SafeExamBrowser.UserInterface.Desktop/Controls/Taskbar/KeyboardLayoutControl.xaml.cs

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+/*
+ * 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.Linq;
+using System.Threading.Tasks;
+using System.Windows;
+using System.Windows.Automation;
+using System.Windows.Controls;
+using System.Windows.Controls.Primitives;
+using System.Windows.Media;
+using SafeExamBrowser.I18n.Contracts;
+using SafeExamBrowser.SystemComponents.Contracts.Keyboard;
+using SafeExamBrowser.UserInterface.Contracts.Shell;
+
+namespace SafeExamBrowser.UserInterface.Desktop.Controls.Taskbar
+{
+	internal partial class KeyboardLayoutControl : UserControl, ISystemControl
+	{
+		private readonly IKeyboard keyboard;
+		private readonly IText text;
+
+		internal KeyboardLayoutControl(IKeyboard keyboard, IText text)
+		{
+			this.keyboard = keyboard;
+			this.text = text;
+
+			InitializeComponent();
+			InitializeKeyboardLayoutControl();
+		}
+
+		public void Close()
+		{
+			Dispatcher.Invoke(() => Popup.IsOpen = false);
+		}
+
+		private void InitializeKeyboardLayoutControl()
+		{
+			var originalBrush = Button.Background;
+
+			InitializeLayouts();
+
+			keyboard.LayoutChanged += Keyboard_LayoutChanged;
+			Button.Click += (o, args) =>
+			{
+				Popup.IsOpen = !Popup.IsOpen;
+				Task.Delay(200).ContinueWith(_ => this.Dispatcher.BeginInvoke((System.Action) (() =>
+				{
+					((LayoutsStackPanel.Children[0] as ContentControl).Content as UIElement).Focus();
+				})));
+			};
+			var lastOpenedBySpacePress = false;
+			Button.PreviewKeyDown += (o, args) =>
+			{
+				// For some reason, the popup immediately closes again if opened by a Space Bar key event - as a mitigation,
+				// we record the space bar event and leave the popup open for at least 3 seconds.
+				if (args.Key == System.Windows.Input.Key.Space)
+				{
+					lastOpenedBySpacePress = true;
+				}
+			};
+			Button.MouseLeave += (o, args) => Task.Delay(250).ContinueWith(_ => Dispatcher.Invoke(() =>
+			{
+				if (Popup.IsOpen && lastOpenedBySpacePress)
+				{
+					return;
+				}
+				Popup.IsOpen = Popup.IsMouseOver;
+			}));
+			Popup.CustomPopupPlacementCallback = new CustomPopupPlacementCallback(Popup_PlacementCallback);
+			Popup.MouseLeave += (o, args) => Task.Delay(250).ContinueWith(_ => Dispatcher.Invoke(() =>
+			{
+				if (Popup.IsOpen && lastOpenedBySpacePress)
+				{
+					return;
+				}
+				Popup.IsOpen = IsMouseOver;
+			}));
+
+			Popup.Opened += (o, args) =>
+			{
+				Background = Brushes.LightGray;
+				Button.Background = Brushes.LightGray;
+			};
+
+			Popup.Closed += (o, args) =>
+			{
+				Background = originalBrush;
+				Button.Background = originalBrush;
+				lastOpenedBySpacePress = false;
+			};
+		}
+
+		private void Keyboard_LayoutChanged(IKeyboardLayout layout)
+		{
+			Dispatcher.InvokeAsync(() => SetCurrent(layout));
+		}
+
+		private CustomPopupPlacement[] Popup_PlacementCallback(Size popupSize, Size targetSize, Point offset)
+		{
+			return new[]
+			{
+				new CustomPopupPlacement(new Point(targetSize.Width / 2 - popupSize.Width / 2, -popupSize.Height), PopupPrimaryAxis.None)
+			};
+		}
+
+		private void InitializeLayouts()
+		{
+			foreach (var layout in keyboard.GetLayouts())
+			{
+				var button = new KeyboardLayoutButton(layout);
+
+				button.LayoutSelected += (o, args) => ActivateLayout(layout);
+				LayoutsStackPanel.Children.Add(button);
+
+				if (layout.IsCurrent)
+				{
+					SetCurrent(layout);
+				}
+			}
+		}
+
+		private void ActivateLayout(IKeyboardLayout layout)
+		{
+			Popup.IsOpen = false;
+			keyboard.ActivateLayout(layout.Id);
+		}
+
+		private void SetCurrent(IKeyboardLayout layout)
+		{
+			var name = layout.CultureName?.Length > 3 ? String.Join(string.Empty, layout.CultureName.Split(' ').Where(s => Char.IsLetter(s.First())).Select(s => s.First())) : layout.CultureName;
+			var tooltip = text.Get(TextKey.SystemControl_KeyboardLayoutTooltip).Replace("%%LAYOUT%%", layout.CultureName);
+
+			foreach (var child in LayoutsStackPanel.Children)
+			{
+				if (child is KeyboardLayoutButton layoutButton)
+				{
+					layoutButton.IsCurrent = layout.Id == layoutButton.LayoutId;
+				}
+			}
+
+			LayoutCultureCode.Text = layout.CultureCode;
+			Button.ToolTip = tooltip;
+
+			AutomationProperties.SetName(Button, tooltip);
+		}
+
+		private void Popup_KeyUp(object sender, System.Windows.Input.KeyEventArgs e)
+		{
+			if (e.Key == System.Windows.Input.Key.Enter || e.Key == System.Windows.Input.Key.Escape)
+			{
+				Popup.IsOpen = false;
+				Button.Focus();
+			}
+		}
+	}
+}