Example #1
0
        /// <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);
        }