Eye Gaze Aware Discussion

GazeAware.cs

using System;
using System.Runtime.InteropServices;
using System.Windows;
using System.Windows.Interop;
using ToltTech.Integration.Win32;

namespace ToltTech.Integration
{
    public static class GazeAware
    {
        private const long WS_TOBIIGAZEAWARE = 0x2L;
        private const string EyeGazeAware = "eyegaze:aware";
        private static readonly IntPtr pStr = Marshal.StringToHGlobalUni(EyeGazeAware);

        public static void SetGazeAware(Window window)
        {
            var hwnd = new WindowInteropHelper(window).Handle;

            // Tobii Computer Control gaze aware indicator
            var windowStyle = User32.GetWindowLong(hwnd, User32.GWL_EXSTYLE) | WS_TOBIIGAZEAWARE;
            if (User32.SetWindowLong(hwnd, User32.GWL_EXSTYLE, windowStyle) == IntPtr.Zero)
            {
                Marshal.ThrowExceptionForHR(Marshal.GetLastWin32Error());
            }

            // MSFT Windows Input team proposal
            if (!User32.SetProp(hwnd, EyeGazeAware, pStr))
            {
                Marshal.ThrowExceptionForHR(Marshal.GetLastWin32Error());
            }

            window.Unloaded += (object sender, RoutedEventArgs e) =>
            {
                User32.RemoveProp(hwnd, EyeGazeAware);
            };
        }

        public static bool IsGazeAware()
        {
            var foregroundWindowHwnd = User32.GetForegroundWindow();
            if (foregroundWindowHwnd == IntPtr.Zero)
            {
                // The foreground window can be NULL in certain circumstances, such as when a window is losing activation.
                return false;
            }

            var tobiiGazeAware = (User32.GetWindowLong(foregroundWindowHwnd, User32.GWL_EXSTYLE) & WS_TOBIIGAZEAWARE) == WS_TOBIIGAZEAWARE;
            var eyeGazeAware = User32.GetProp(foregroundWindowHwnd, EyeGazeAware) != IntPtr.Zero;

            return tobiiGazeAware || eyeGazeAware;
        }
    }
}

Program.cs

using System;
using System.Text;
using System.Threading;
using ToltTech.Integration.Win32;

namespace FindGazeAware
{
    internal class Program
    {
        static void Main()
        {
            while (true)
            {
                var foregroundWindowHwnd = User32.GetForegroundWindow();

                int size = User32.GetWindowTextLength(foregroundWindowHwnd);
                if (size++ > 0 && User32.IsWindowVisible(foregroundWindowHwnd))
                {
                    var windowTitle = new StringBuilder(size);
                    User32.GetWindowText(foregroundWindowHwnd, windowTitle, size);

                    Console.WriteLine($"{windowTitle} - IsGazeAware: {ToltTech.Integration.GazeAware.IsGazeAware()}");
                }

                Thread.Sleep(5000);
            }
        }
    }
}