/// <summary>
/// A local function which handles the RawInput messages
/// </summary>
/// <param name="hWnd">IntPtr</param>
/// <param name="msg">int</param>
/// <param name="wParam">IntPtr</param>
/// <param name="lParam">IntPtr</param>
/// <param name="handled">ref bool</param>
/// <returns>IntPtr</returns>
private static IntPtr HandleRawInputMessages(IntPtr hWnd, int msg, IntPtr wParam, IntPtr lParam, ref bool handled)
{
var windowsMessage = (WindowsMessages)msg;
switch (windowsMessage)
{
case WindowsMessages.WM_INPUT_DEVICE_CHANGE:
bool isNew = wParam.ToInt64() == 1;
IntPtr deviceHandle = lParam;
// Add to cache
if (isNew)
{
DeviceCache[deviceHandle] = RawInputApi.GetDeviceInformation(deviceHandle);
}
DeviceChangeSubject.OnNext(new RawInputDeviceChangeEventArgs
{
Added = isNew,
DeviceInformation = DeviceCache[deviceHandle]
});
// Remove from cache
if (!isNew)
{
DeviceCache.Remove(deviceHandle);
}
break;
case WindowsMessages.WM_INPUT:
int outSize;
int size = Marshal.SizeOf(typeof(RawInput));
outSize = RawInputApi.GetRawInputData(lParam, RawInputDataCommands.Input, out var rawInput, ref size, Marshal.SizeOf(typeof(RawInputHeader)));
if (outSize != -1)
{
RawInputSubject.OnNext(new RawInputEventArgs
{
IsForeground = wParam.ToInt64() == 0,
RawInput = rawInput
});
}
break;
}
return(IntPtr.Zero);
}
/// <summary>
/// Create an observable to monitor raw-input device changes
/// </summary>
public static IObservable <RawInputDeviceChangeEventArgs> MonitorRawInputDeviceChanges(params RawInputDevices[] devices)
{
RawInputApi.RegisterRawInput(WinProcHandler.Instance.Handle, RawInputDeviceFlags.DeviceNotify, devices);
return(OnDeviceChanges);
}