/// <summary>
/// The Windows message interception for gesture events handling
/// </summary>
/// <param name="hWnd">WndProc hWnd</param>
/// <param name="msg">WndProc msg</param>
/// <param name="wParam">WndProc wParam</param>
/// <param name="lParam">WndProc lParam</param>
/// <returns>WndProc return</returns>
public override uint WindowProc(IntPtr hWnd, int msg, IntPtr wParam, IntPtr lParam)
{
//We care only for gesture events
if (msg != User32.WM_GESTURE)
{
return(0);
}
GESTUREINFO gestureInfo = new GESTUREINFO
{
cbSize = (uint)Marshal.SizeOf(typeof(GESTUREINFO))
};
bool result = User32.GetGestureInfo(lParam, ref gestureInfo);
if (!result)
{
throw new Exception("Cannot get gesture information");
}
//Decode the gesture info and get the message event argument
GestureEventArgs eventArgs = new GestureEventArgs(this, ref gestureInfo);
try
{
//Fire the event using the event map
_eventMap[MapWM2EventId(gestureInfo.dwID, gestureInfo.dwFlags)].Invoke(this, eventArgs);
}
catch (ArgumentOutOfRangeException) //In case future releases will introduce new event values
{
}
//Keep the last message for relative calculations
LastEvent = eventArgs;
//Keep the first message for relative calculations
if (eventArgs.IsBegin)
{
LastBeginEvent = eventArgs;
}
User32.CloseGestureInfoHandle(lParam);
return(1);
}