internal static bool IsAltTabWindow(IntPtr windowHandle)
{
if (!WindowsFunctions.IsWindowVisible(windowHandle))
{
return(false);
}
const int GA_ROOTOWNER = 3;
var hwndTry = WindowsFunctions.GetAncestor(windowHandle, GA_ROOTOWNER);
var hwndWalk = IntPtr.Zero;
while (hwndTry != hwndWalk)
{
hwndWalk = hwndTry;
hwndTry = WindowsFunctions.GetLastActivePopup(hwndWalk);
if (WindowsFunctions.IsWindowVisible(hwndTry))
{
break;
}
}
if (hwndWalk != windowHandle)
{
return(false);
}
// the following removes some task tray programs and "Program Manager"
var titleBarInfo = new WindowsFunctions.TITLEBARINFO();
titleBarInfo.cbSize = Marshal.SizeOf(titleBarInfo);
WindowsFunctions.GetTitleBarInfo(windowHandle, ref titleBarInfo);
const int STATE_SYSTEM_INVISIBLE = 0x00008000;
if ((titleBarInfo.rgstate[0] & STATE_SYSTEM_INVISIBLE) != 0)
{
return(false);
}
// Tool windows should not be displayed either, these do not appear in the
// task bar.
const int GWL_EXSTYLE = -20;
const long WS_EX_TOOLWINDOW = 0x00000080L;
if ((WindowsFunctions.GetWindowLong(windowHandle, GWL_EXSTYLE) & WS_EX_TOOLWINDOW) != 0)
{
return(false);
}
WindowsFunctions.DwmGetWindowAttribute(windowHandle,
WindowsFunctions.DWMWINDOWATTRIBUTE.Cloaked,
out var isCloaked,
Marshal.SizeOf(typeof(bool)));
if (isCloaked)
{
return(false);
}
return(true);
}
