/// <summary>
/// Create an observable for the specified Control (Form)
/// </summary>
public static IObservable <WindowMessageInfo> WinProcFormsMessages(this Control control)
{
var winProcListener = new WinProcListener(control);
return(Observable.Create <WindowMessageInfo>(observer =>
{
winProcListener.AddHook(WindowMessageHandler);
// This handles the message, and generates the observable OnNext
IntPtr WindowMessageHandler(IntPtr hwnd, int msg, IntPtr wParam, IntPtr lParam, ref bool handled)
{
var message = WindowMessageInfo.Create(hwnd, msg, wParam, lParam);
observer.OnNext(message);
// ReSharper disable once AccessToDisposedClosure
if (winProcListener.IsDisposed || message.Message == WindowsMessages.WM_DESTROY)
{
observer.OnCompleted();
}
return IntPtr.Zero;
}
return Disposable.Create(() =>
{
winProcListener.Dispose();
});
})
// Make sure there is always a value produced when connecting
.Publish()
.RefCount());
}
/// <summary>
/// Create an observable for the specified window or HwndSource
/// </summary>
/// <param name="window">Window</param>
/// <param name="hWndSource">HwndSource</param>
/// <param name="before">Func which does something as soon as the observable is created</param>
/// <param name="disposeAction">Action which disposes something when the observable is disposed</param>
/// <returns>IObservable</returns>
internal static IObservable <WindowMessageInfo> WinProcMessages <TState>(Window window, HwndSource hWndSource, Func <IntPtr, TState> before = null, Action <TState> disposeAction = null)
{
if (window == null && hWndSource == null)
{
throw new NotSupportedException("One of Window or HwndSource must be supplied");
}
return(Observable.Create <WindowMessageInfo>(observer =>
{
// This handles the message, and generates the observable OnNext
IntPtr WindowMessageHandler(IntPtr hWnd, int msg, IntPtr wParam, IntPtr lParam, ref bool handled)
{
observer.OnNext(WindowMessageInfo.Create(hWnd, msg, wParam, lParam));
// ReSharper disable once AccessToDisposedClosure
if (hWndSource.IsDisposed)
{
observer.OnCompleted();
}
return IntPtr.Zero;
}
TState state = default;
void HwndSourceDisposedHandle(object sender, EventArgs e)
{
observer.OnCompleted();
}
void RegisterHwndSource()
{
if (before != null)
{
state = before(hWndSource.Handle);
}
hWndSource.Disposed += HwndSourceDisposedHandle;
hWndSource.AddHook(WindowMessageHandler);
}
if (window != null)
{
hWndSource = window.ToHwndSource();
}
if (hWndSource != null)
{
RegisterHwndSource();
}
else if (window != null)
{
// No, try to get it later
window.SourceInitialized += (sender, args) =>
{
hWndSource = window.ToHwndSource();
RegisterHwndSource();
// Simulate the WM_NCCREATE
observer.OnNext(WindowMessageInfo.Create(hWndSource.Handle, (int)WindowsMessages.WM_NCCREATE, IntPtr.Zero, IntPtr.Zero));
};
}
return Disposable.Create(() =>
{
disposeAction?.Invoke(state);
hWndSource.Disposed -= HwndSourceDisposedHandle;
hWndSource.RemoveHook(WindowMessageHandler);
hWndSource.Dispose();
});
})
// Make sure there is always a value produced when connecting
.Publish()
.RefCount());
}
