internal override void Start(IWinMessageFilter filter)
{
if (_dispatcher == null)
{
// using this hack so the new thread will start running before this function returns
using (var hack = new WrappedManualResetEvent())
{
var loopThread = new Thread(new ThreadStart(() =>
{
PlatformInfo.Current.Log.Debug("NTwain internal message loop is starting.");
_dispatcher = Dispatcher.CurrentDispatcher;
if (!PlatformInfo.Current.IsOnMono)
{
_hook = new WindowsHook(filter);
Handle = _hook.Handle;
}
hack.Set();
Dispatcher.Run();
// if dispatcher shutsdown we'll get here so make everything uninitialized
_dispatcher = null;
if (_hook != null)
{
_hook.Dispose();
_hook = null;
Handle = IntPtr.Zero;
}
}));
loopThread.IsBackground = true;
loopThread.SetApartmentState(ApartmentState.STA);
loopThread.Start();
hack.Wait();
}
}
}
public WindowsHook(IWinMessageFilter filter)
{
_filter = filter;
HwndSource win = null;
try
{
// hook into windows msg loop for old twain to post msgs.
// the style values are purely guesses here with
// CS_NOCLOSE, WS_TILEDWINDOW, and WS_EX_APPWINDOW
win = new HwndSource(0x0200, 0xCF0000, 0x40000, 0, 0, "NTWAIN_LOOPER", IntPtr.Zero);
Handle = win.Handle;
win.AddHook(WndProc);
_win = win;
}
catch
{
if (win != null)
{
win.Dispose();
}
throw;
}
}
internal override void Stop()
{
//Invoke(() =>
//{
System.Windows.Forms.Application.RemoveMessageFilter(this);
_filter = null;
//});
}
internal override void Start(IWinMessageFilter filter)
{
//Invoke(() =>
//{
_filter = filter;
System.Windows.Forms.Application.AddMessageFilter(this);
//});
}
internal override void Start(IWinMessageFilter filter)
{
_filter = filter;
_hooker = HwndSource.FromHwnd(Handle);
_hooker.AddHook(FilterMessage);
}
internal abstract void Start(IWinMessageFilter filter);
