c# - Detect if on-screen keyboard is open (TabTip.exe)

Question

I am working on a WPF/C# application for completing forms. I am trying to find a way to determine if the TapTip keyboard (TabTip.exe / metro-like keyboard for windows 8 desktop) is minimized / not visible in windows 8.

I have been able to detect if the osk keyboard (osk.exe / windows accessibility on-screen keyboard) is minimized, but the same process does not seem to work with the TabTip keyboard.

To detect if the keyboard is minimized I:
1. Find the keyboard's process
2. Get the MainWindowHandle
3. Use the showCmd property of the WINDOWPLACEMENT (found using MainWindowHandle)
4. Use showCmd value to determine if window is minimized

The problems I have run into are:
- the TabTip process has a MainWindowHandle of 0 (so I can't use it to find the WINDOWPLACEMENT information)
- the values for WINDOWPLACEMENT.showCmd are the same when TabTip is open and minimized

In order to find the handle of the TabTip window I used ENUMWINDOWS to get all the window handles, GETWINDOWTHREADPROCESSID to get the process ids, then compared the ids to the TabTip process id.

Any help with this would be appreciated. Also this is my first post. I think I did this right, but if not please let me know how to fix it.

Answer 1

I tried a few different methods before finding one which works. Using IsWindowVisible() didn't work and I also didn't have any joy with GetWindowPlacement() or GetIconic(). In the end I used GetWindowLong() and checked for the WS_VISIBLE coming back. A quick console app to demonstrate is as follows:

using System;
using System.Diagnostics;
using Microsoft.Win32;
using System.Runtime.InteropServices;
using System.Threading;

namespace CSharpTesting
{
    class Program
    {
        /// <summary>
        /// The window is initially visible. See http://msdn.microsoft.com/en-gb/library/windows/desktop/ms632600(v=vs.85).aspx.
        /// </summary>
        public const UInt32 WS_VISIBLE  = 0X94000000;
        /// <summary>
        /// Specifies we wish to retrieve window styles.
        /// </summary>
        public const int GWL_STYLE = -16;

        [DllImport("user32.dll")]
        public static extern IntPtr FindWindow(String sClassName, String sAppName);

        [DllImport("user32.dll", SetLastError = true)]
        static extern UInt32 GetWindowLong(IntPtr hWnd, int nIndex);

        static void Main(string[] args)
        {
            // Crappy loop to poll window state.
            while (true)
            {
                if (IsKeyboardVisible())
                {
                    Console.WriteLine("keyboard is visible");
                }
                else
                {
                    Console.WriteLine("keyboard is NOT visible");
                }

                Thread.Sleep(1000);
            }
        }

        /// <summary>
        /// Gets the window handler for the virtual keyboard.
        /// </summary>
        /// <returns>The handle.</returns>
        public static IntPtr GetKeyboardWindowHandle()
        {
            return FindWindow("IPTip_Main_Window", null);
        }

        /// <summary>
        /// Checks to see if the virtual keyboard is visible.
        /// </summary>
        /// <returns>True if visible.</returns>
        public static bool IsKeyboardVisible()
        {
            IntPtr keyboardHandle = GetKeyboardWindowHandle();

            bool visible = false;

            if (keyboardHandle != IntPtr.Zero)
            {
                UInt32 style = GetWindowLong(keyboardHandle, GWL_STYLE);
                visible = (style == WS_VISIBLE);
            }

            return visible;
        }
    }
}