Keyboard layout indicator

Add-Type -Language CSharp -ReferencedAssemblies @(
    "System.Windows.Forms",
    "System.Drawing"
) -TypeDefinition @"

using System;
using System.Drawing;
using System.Windows.Forms;
using System.Runtime.InteropServices;
using System.Globalization;

public class KeyboardTrayApp : Form
{
    NotifyIcon trayIcon;
    Timer timer;
    ContextMenuStrip menu;

    [DllImport("user32.dll")]
    private static extern IntPtr GetKeyboardLayout(uint idThread);

    [DllImport("user32.dll")]
    private static extern IntPtr GetForegroundWindow();

    [DllImport("user32.dll")]
    private static extern uint GetWindowThreadProcessId(IntPtr hWnd, IntPtr ProcessId);

    string lastLang = "";

    public KeyboardTrayApp()
    {
        ShowInTaskbar = false;
        WindowState = FormWindowState.Minimized;

        trayIcon = new NotifyIcon();
        trayIcon.Visible = true;

        menu = new ContextMenuStrip();
        menu.Items.Add("Exit", null, OnExit);
        trayIcon.ContextMenuStrip = menu;

        timer = new Timer();
        timer.Interval = 200;   // Fast, but lightweight
        timer.Tick += PollLayout;
        timer.Start();

        PollLayout(null, null);
    }

    private void OnExit(object sender, EventArgs e)
    {
        trayIcon.Visible = false;
        timer.Stop();
        Application.Exit();
    }

    private void PollLayout(object sender, EventArgs e)
    {
        string lang = GetLayoutCode();

        if (lang == lastLang)
            return;

        lastLang = lang;

        trayIcon.Icon = CreateTextIcon(lang);
        trayIcon.Text = "Keyboard: " + lang;
    }

    private string GetLayoutCode()
    {
        IntPtr hwnd = GetForegroundWindow();

        if (hwnd == IntPtr.Zero)
            return "??";

        uint threadId = GetWindowThreadProcessId(hwnd, IntPtr.Zero);

        IntPtr layout = GetKeyboardLayout(threadId);
        int langId = ((int)layout) & 0xFFFF;

        try
        {
            CultureInfo culture = CultureInfo.GetCultureInfo(langId);
            return culture.TwoLetterISOLanguageName.ToUpper();
        }
        catch
        {
            return "??";
        }
    }

    private Icon CreateTextIcon(string text)
    {
        Bitmap bmp = new Bitmap(16, 16);
        Graphics g = Graphics.FromImage(bmp);

        g.Clear(Color.Black);

        using (Font font = new Font("Segoe UI", 8, FontStyle.Bold))
        using (Brush brush = new SolidBrush(Color.White))
        {
            SizeF size = g.MeasureString(text, font);
            g.DrawString(text, font, brush,
                (16 - size.Width) / 2,
                (16 - size.Height) / 2);
        }

        return Icon.FromHandle(bmp.GetHicon());
    }
}

"@

$app = New-Object KeyboardTrayApp
[System.Windows.Forms.Application]::Run($app)