Various small updates

README.md

@@ -7,13 +7,23 @@ Sample to capture inputs from Precision Touchpad by [Raw Input](https://docs.mic
 
 ## Requirements
 
-- .NET 5.0
+- .NET 9.0
 
-## Example
+Originally built on .NET 5.0, and upgraded in 2025, but no changes were needed. So, it should easily run on older versions of .NET
 
-When five fingers are touching the touchpad of Surface Pro 4 Type Cover, five contacts appear with each coordinates.
+## Examples
 
-![Screenshot](Images/Screenshot.png)
+When there are no fingers touching the touchpad, the window turns red
+
+![Screenshot](Images/screenshot-red.png)
+
+When five fingers are touching the touchpad of Surface Pro 4 Type Cover, five contacts appear with each coordinates, and the window turns green
+
+![Screenshot](Images/screenshot-green.png)
+
+When minimized the program shows up as a circle icon in the tray which is red when no touch is detected. When touch is detected it turns green and shows the number of touches.
+
+![Screenshot](Images/screenshot-tray.png)
 
 ## License
 

Source/RawInput.Touchpad/MainWindow.xaml

@@ -3,7 +3,7 @@
 		xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
 		x:Name="WindowRoot"
 		Title="RawInput Touchpad"
-		Height="260" Width="400" ResizeMode="NoResize">
+		Height="180" Width="300" ResizeMode="CanMinimize">
 	<Grid>
 		<Grid.RowDefinitions>
 			<RowDefinition Height="Auto"/>

Source/RawInput.Touchpad/MainWindow.xaml.cs

@@ -1,7 +1,10 @@
 using System;
 using System.Collections.Generic;
+using System.Drawing;
+using System.IO;
 using System.Linq;
 using System.Text;
+using System.Threading;
 using System.Threading.Tasks;
 using System.Windows;
 using System.Windows.Controls;
@@ -14,69 +17,218 @@
 
 namespace RawInput.Touchpad
 {
-	public partial class MainWindow : Window
-	{
-		public bool TouchpadExists
-		{
-			get { return (bool)GetValue(TouchpadExistsProperty); }
-			set { SetValue(TouchpadExistsProperty, value); }
-		}
-		public static readonly DependencyProperty TouchpadExistsProperty =
-			DependencyProperty.Register("TouchpadExists", typeof(bool), typeof(MainWindow), new PropertyMetadata(false));
-
-		public string TouchpadContacts
-		{
-			get { return (string)GetValue(TouchpadContactsProperty); }
-			set { SetValue(TouchpadContactsProperty, value); }
-		}
-		public static readonly DependencyProperty TouchpadContactsProperty =
-			DependencyProperty.Register("TouchpadContacts", typeof(string), typeof(MainWindow), new PropertyMetadata(null));
-
-		public MainWindow()
-		{
-			InitializeComponent();
-		}
-
-		private HwndSource _targetSource;
-		private readonly List<string> _log = new();
-
-		protected override void OnSourceInitialized(EventArgs e)
-		{
-			base.OnSourceInitialized(e);
-
-			_targetSource = PresentationSource.FromVisual(this) as HwndSource;
-			_targetSource?.AddHook(WndProc);
-
-			TouchpadExists = TouchpadHelper.Exists();
-
-			_log.Add($"Precision touchpad exists: {TouchpadExists}");
-
-			if (TouchpadExists)
-			{
-				var success = TouchpadHelper.RegisterInput(_targetSource.Handle);
-
-				_log.Add($"Precision touchpad registered: {success}");
-			}
-		}
-
-		private IntPtr WndProc(IntPtr hwnd, int msg, IntPtr wParam, IntPtr lParam, ref bool handled)
-		{
-			switch (msg)
-			{
-				case TouchpadHelper.WM_INPUT:
-					var contacts = TouchpadHelper.ParseInput(lParam);
-					TouchpadContacts = string.Join(Environment.NewLine, contacts.Select(x => x.ToString()));
-
-					_log.Add("---");
-					_log.Add(TouchpadContacts);
-					break;
-			}
-			return IntPtr.Zero;
-		}
-
-		private void Copy_Click(object sender, RoutedEventArgs e)
-		{
-			Clipboard.SetText(string.Join(Environment.NewLine, _log));
-		}
-	}
-}
+    public partial class MainWindow : Window
+    {
+        [System.Runtime.InteropServices.DllImport("user32.dll")]
+        static extern bool DestroyIcon(IntPtr handle);
+
+        public bool TouchpadExists
+        {
+            get { return (bool)GetValue(TouchpadExistsProperty); }
+            set { SetValue(TouchpadExistsProperty, value); }
+        }
+
+        public static readonly DependencyProperty TouchpadExistsProperty =
+            DependencyProperty.Register(
+                "TouchpadExists",
+                typeof(bool),
+                typeof(MainWindow),
+                new PropertyMetadata(false)
+            );
+
+        public string TouchpadContacts
+        {
+            get { return (string)GetValue(TouchpadContactsProperty); }
+            set { SetValue(TouchpadContactsProperty, value); }
+        }
+
+        public static readonly DependencyProperty TouchpadContactsProperty =
+            DependencyProperty.Register(
+                "TouchpadContacts",
+                typeof(string),
+                typeof(MainWindow),
+                new PropertyMetadata(null)
+            );
+
+        // reference to tray icon
+        private System.Windows.Forms.NotifyIcon _notifyIcon;
+
+        // tracks if touch is showing, used to avoid updating the icon if it is already correct
+        private int _touchesShowing = 0;
+
+        // when was the last touch event received
+        private long _lastTouchTime = 0;
+
+        // timer to expire last touch event to detect when no one is touching the track pad anymore
+        private Timer _touchTimer;
+
+        // list of all received touch events
+        private readonly List<string> _log = new();
+
+        public MainWindow()
+        {
+            InitializeComponent();
+
+            // add tray icon
+            _notifyIcon = new System.Windows.Forms.NotifyIcon
+            {
+                Text = "Touchpad Monitor",
+                Visible = true,
+            };
+            SetIconState(System.Drawing.Color.Red, ' ');
+            // restore window on tray icon click
+            _notifyIcon.Click += (s, e) => RestoreWindow();
+            // keep window on top when showing
+            Topmost = true;
+            // start window in bottom right corner
+            var workingArea = SystemParameters.WorkArea;
+            Left = workingArea.Width - Width;
+            Top = workingArea.Height - Height;
+            // start timer to track expired touches
+            _touchTimer = new Timer(TouchTimerCallback, null, 0, 50);
+        }
+
+        protected override void OnClosed(EventArgs e)
+        {
+            base.OnClosed(e);
+
+            _notifyIcon.Dispose();
+        }
+
+        protected override void OnStateChanged(EventArgs e)
+        {
+            base.OnStateChanged(e);
+
+            if (WindowState == WindowState.Minimized)
+            {
+                Hide();
+                _notifyIcon.Visible = true;
+            }
+        }
+
+        protected override void OnSourceInitialized(EventArgs e)
+        {
+            base.OnSourceInitialized(e);
+
+            var targetSource = PresentationSource.FromVisual(this) as HwndSource;
+            targetSource?.AddHook(WndProc);
+
+            TouchpadExists = TouchpadHelper.Exists();
+
+            _log.Add($"Precision touchpad exists: {TouchpadExists}");
+
+            if (TouchpadExists)
+            {
+                var success = TouchpadHelper.RegisterInput(targetSource.Handle);
+
+                _log.Add($"Precision touchpad registered: {success}");
+            }
+
+            Visibility = Visibility.Hidden;
+        }
+
+        private IntPtr WndProc(IntPtr hwnd, int msg, IntPtr wParam, IntPtr lParam, ref bool handled)
+        {
+            switch (msg)
+            {
+                case TouchpadHelper.WM_INPUT:
+                    var contacts = TouchpadHelper.ParseInput(lParam);
+                    _lastTouchTime = DateTimeOffset.UtcNow.ToUnixTimeMilliseconds();
+                    TouchpadContacts = string.Join(
+                        Environment.NewLine,
+                        contacts.Select(x => x.ToString())
+                    );
+
+                    var touchCount = contacts.Length;
+
+                    if (touchCount != _touchesShowing)
+                    {
+                        _touchesShowing = touchCount;
+                        Background = new SolidColorBrush(
+                            System.Windows.Media.Color.FromRgb(144, 238, 144)
+                        );
+                        SetIconState(System.Drawing.Color.Green, touchCount.ToString().ToCharArray()[0]);
+                    }
+
+                    _log.Add("---");
+                    _log.Add(TouchpadContacts);
+                    break;
+            }
+            return IntPtr.Zero;
+        }
+
+        private void Copy_Click(object sender, RoutedEventArgs e)
+        {
+            Clipboard.SetText(string.Join(Environment.NewLine, _log));
+        }
+
+        private void TouchTimerCallback(object state)
+        {
+            var now = DateTimeOffset.UtcNow.ToUnixTimeMilliseconds();
+            if (now - _lastTouchTime > 100 && _touchesShowing > 0)
+            {
+                Dispatcher.Invoke(() =>
+                {
+                    _touchesShowing = 0;
+                    TouchpadContacts = "";
+                    Background = new SolidColorBrush(
+                        System.Windows.Media.Color.FromRgb(238, 144, 144)
+                    );
+                    SetIconState(System.Drawing.Color.Red, ' ');
+                });
+            }
+        }
+
+        private void RestoreWindow()
+        {
+            Show();
+            WindowState = WindowState.Normal;
+            Activate();
+            _notifyIcon.Visible = false;
+        }
+
+        private void SetIconState(System.Drawing.Color color, char label)
+        {
+            using (var icon = CreateCircleIcon(color, label))
+            {
+                _notifyIcon.Icon = icon;
+                DestroyIcon(icon.Handle);
+            }
+        }
+
+        private static Icon CreateCircleIcon(System.Drawing.Color color, char character)
+        {
+            int size = 32;
+            using (var bitmap = new Bitmap(size, size))
+            {
+                using (var graphics = Graphics.FromImage(bitmap))
+                {
+                    graphics.Clear(System.Drawing.Color.Transparent);
+
+                    // Draw the circle with the specified color
+                    using (var brush = new SolidBrush(color))
+                    {
+                        graphics.FillEllipse(brush, 0, 0, size, size);
+                    }
+
+                    // Set up the font and brush for the character
+                    using var font = new Font(System.Drawing.FontFamily.GenericSansSerif, 6, System.Drawing.FontStyle.Bold);
+                    using var textBrush = new SolidBrush(System.Drawing.Color.White);
+                    // Measure the size of the character to center it
+                    SizeF textSize = graphics.MeasureString(character.ToString(), font);
+
+                    // Calculate the position to center the character
+                    float x = (size - textSize.Width) / 2;
+                    float y = (size - textSize.Height) / 2;
+
+                    // Draw the character centered on the circle
+                    graphics.DrawString(character.ToString(), font, textBrush, x, y);
+                }
+
+                IntPtr hIcon = bitmap.GetHicon();
+                return System.Drawing.Icon.FromHandle(hIcon);
+            }
+        }
+
+    }
+}

Source/RawInput.Touchpad/RawInput.Touchpad.csproj

@@ -2,8 +2,9 @@
 
   <PropertyGroup>
     <OutputType>WinExe</OutputType>
-    <TargetFramework>net5.0-windows</TargetFramework>
+    <TargetFramework>net9.0-windows</TargetFramework>
     <UseWPF>true</UseWPF>
+    <UseWindowsForms>true</UseWindowsForms>
     <Authors>emoacht</Authors>
     <Copyright>Copyright © 2021 emoacht</Copyright>
     <PackageLicenseExpression>MIT</PackageLicenseExpression>

Source/RawInput.Touchpad/TouchpadHelper.cs

@@ -297,7 +297,8 @@ public static bool RegisterInput(IntPtr windowHandle)
 			{
 				usUsagePage = 0x000D,
 				usUsage = 0x0005,
-				dwFlags = 0, // WM_INPUT messages come only when the window is in the foreground.
+				dwFlags = 0x00000100, // WM_INPUT messages come regardless of what window is in focus
+				// dwFlags = 0, // WM_INPUT messages come only when the window is in the foreground.
 				hwndTarget = windowHandle
 			};