NotificationUI.xaml.cs

using System;
using System.Reflection;
using System.Runtime.InteropServices;
using System.Windows;
using System.Windows.Controls.Primitives;
using System.Windows.Interop;
using System.Windows.Threading;

namespace Dynamo.Notifications.View
{
    /// <summary>
    /// Interaction logic for NotificationUI.xaml
    /// </summary>
    public partial class NotificationUI : Popup
    {
        private NotificationsUIViewModel notificationsUIViewModel;

        public NotificationUI()
        {
            InitializeComponent();

            if (notificationsUIViewModel == null)
            {
                notificationsUIViewModel = new NotificationsUIViewModel();
            }

            //When if the Windows Handedness parameter is set to Right-handed (True) then we need to set the _menuDropAlignment field to false otherwise the Notifications popup will be shown in a wrong Position
            var ifLeft = SystemParameters.MenuDropAlignment;
            if (ifLeft) //If MenuDropAlignment = Right-handed(True)
            {
                var t = typeof(SystemParameters);
                var field = t.GetField("_menuDropAlignment", BindingFlags.NonPublic | BindingFlags.Static);
                field.SetValue(null, false); //Set the field to Left-handed(false)
            }

            DataContext = notificationsUIViewModel;

            //The BackgroundRectangle represent the tooltip background rectangle that is drawn over a Canvas
            //Needs to be moved 10 pixels over the X axis to show the direction pointers (Height was already increased above)
            //Needs to be moved 10 pixels over the Y axis to show the shadow at top and bottom.
            BackgroundRectangle.Rect = new Rect(notificationsUIViewModel.PopupBordersOffSet, notificationsUIViewModel.PopupBordersOffSet, notificationsUIViewModel.PopupRectangleWidth, notificationsUIViewModel.PopupRectangleHeight);

            //The CustomRichTextBox has a margin of 10 in left and 10 in right, also there is a indentation for drawing the PointerDirection of 10 of each side so that's why we are subtracting 40.
            mainPopupGrid.Width = notificationsUIViewModel.PopupRectangleWidth;
            mainPopupGrid.Height = notificationsUIViewModel.PopupRectangleHeight;
            mainPopupGrid.Margin = new Thickness(notificationsUIViewModel.PopupBordersOffSet, notificationsUIViewModel.PopupBordersOffSet, 0, 0);


        }

        internal void UpdatePopupLocation()
        {
            if (IsOpen)
            {
                var positionMethod = typeof(Popup).GetMethod("UpdatePosition", System.Reflection.BindingFlags.NonPublic | System.Reflection.BindingFlags.Instance);
                positionMethod.Invoke(this, null);
            }
        }

        internal void UpdatePopupSize()
        {
            BackgroundRectangle.Rect = new Rect(notificationsUIViewModel.PopupBordersOffSet,
                                                notificationsUIViewModel.PopupBordersOffSet,
                                                notificationsUIViewModel.PopupRectangleWidth,
                                                notificationsUIViewModel.PopupRectangleHeight);

            this.Height = notificationsUIViewModel.PopupRectangleHeight + notificationsUIViewModel.PopupBordersOffSet + 10;
        }

        // Wait until the Popup is opened to set focus back to the main window.
        // This is necessary because Popup opens asynchronously, and WebView2 (HWND-based)
        // can steal focus. We explicitly reclaim native focus to ensure correct interaction
        // with the main window (e.g., close button, click handling).
        private void NotificationUI_Opened(object sender, EventArgs e)
        {
            // Ensure the application and main window are available and fully loaded.
            ForceMainWindowFocus();
        }

        private void ForceMainWindowFocus()
        {
            if (Application.Current?.MainWindow == null)
                return;

            if (!ReleaseCapture())
            {
                int errorCode = Marshal.GetLastWin32Error();
                Console.WriteLine($"ReleaseCapture failed with error code: {errorCode}");
            }

            if (!SetForegroundWindow(new WindowInteropHelper(Application.Current.MainWindow).Handle))
            {
                int errorCode = Marshal.GetLastWin32Error();
                Console.WriteLine($"SetForegroundWindow failed with error code: {errorCode}");
            }   
        }

        [DllImport("user32.dll", SetLastError = true)]
        [return: MarshalAs(UnmanagedType.Bool)]
        private static extern bool ReleaseCapture();

        [DllImport("user32.dll", SetLastError = true)]
        [return: MarshalAs(UnmanagedType.Bool)]
        private static extern bool SetForegroundWindow(IntPtr hWnd);
    }
}