Question

I am trying to do something like Kinect adventures with Kinect SDK i.e. when the mouse stays in a certain area for a specific period of time, the native click event is to be fired.
The problem is that I do not get the expected results, since I get random clicking most times. I tried to check with breakpoints etc.
Most often, when my hand is not visible, the cursor goes to the corner of the screen and starts clicking. This is most probably because Math.Abs(lastX - cursorX) < threshold sets to true.

I have tried changing the threshold values to 200, but it fires a click st the start, and afterwards I am not get expected left clicks, when I hold the cursor in a certain position for some time. Any suggestions would be greatly appreciated. Here’s the code:

//SkeletonFrameReadyevent

foreach (SkeletonData sd in e.SkeletonFrame.Skeletons)
{
    if (sd.TrackingState == SkeletonTrackingState.Tracked)
    {
        // make sure both hands are tracked
        if (sd.Joints[JointID.HandLeft].TrackingState == JointTrackingState.Tracked &&
            sd.Joints[JointID.HandRight].TrackingState == JointTrackingState.Tracked)
        {
            int cursorX, cursorY;

        // get the left and right hand Joints
        Joint jointRight = sd.Joints[JointID.HandRight];
        Joint jointLeft = sd.Joints[JointID.HandLeft];

        // scale those Joints to the primary screen width and height
        Joint scaledRight = jointRight.ScaleTo((int)SystemParameters.PrimaryScreenWidth, (int)SystemParameters.PrimaryScreenHeight, SkeletonMaxX, SkeletonMaxY);
        Joint scaledLeft = jointLeft.ScaleTo((int)SystemParameters.PrimaryScreenWidth, (int)SystemParameters.PrimaryScreenHeight, SkeletonMaxX, SkeletonMaxY);

        // figure out the cursor position based on left/right handedness

            cursorX = (int)scaledRight.Position.X;
            cursorY = (int)scaledRight.Position.Y;
        //default false, for mouse move, set to true for mouse click
        bool leftClick;

        if (lastY == 0)
        {
            lastX = cursorX;
            lastY = cursorY;
        }

        leftClick = false;
        if (Math.Abs(lastX - cursorX) < threshold && Math.Abs(lastY - cursorY) < threshold)
        {
            if (Math.Abs(lastClick.Subtract(DateTime.Now).TotalSeconds) > 1)
            {
                //Mouse click here
                leftClick = true;
            }
        }

        //Mouse click when leftDown is true, else Mousemove
        NativeMethods.SendMouseInput(cursorX, cursorY, (int)SystemParameters.PrimaryScreenWidth, (int)SystemParameters.PrimaryScreenHeight, leftClick);
        return;
        }
    }
}

NativeMthods.cs class has this function:

public static void SendMouseInput(int positionX, int positionY, int maxX, int maxY, bool leftDown)
{
    if(positionX > int.MaxValue)
        throw new ArgumentOutOfRangeException("positionX");
    if(positionY > int.MaxValue)
        throw new ArgumentOutOfRangeException("positionY");

    Input[] i = new Input[2];

    // move the mouse to the position specified
    i[0] = new Input();
    i[0].Type = InputMouse;
    i[0].MouseInput.X = (positionX * 65535) / maxX;
    i[0].MouseInput.Y = (positionY * 65535) / maxY;
    i[0].MouseInput.Flags = MouseEventAbsolute | MouseEventMove;

    // determine if we need to send a mouse down or mouse up event
    if(leftDown)
    {
        i[1] = new Input();
        i[1].Type = InputMouse;
        i[1].MouseInput.Flags = MouseEventLeftDown;
        i[1].MouseInput.Flags |= MouseEventLeftUp;
    }

    // send it off
    uint result = SendInput(2, i, Marshal.SizeOf(i[0]));
    if(result == 0)
        throw new Win32Exception(Marshal.GetLastWin32Error());
}

Answer 1

Try something like this:

    public class myMouseClass: IMessageFilter //Must implement IMessageFilter
    {
        [DllImport("user32.dll", CharSet = CharSet.Auto, CallingConvention = CallingConvention.StdCall)]
        public static extern void mouse_event(long dwFlags, long dx, long dy, long cButtons, long dwExtraInfo);

        //Constants 
        private const int MOUSEEVENTF_LEFTDOWN = 0x02;
        private const int MOUSEEVENTF_LEFTUP = 0x04;
        private const int MOUSEEVENTF_RIGHTDOWN = 0x08;
        private const int MOUSEEVENTF_RIGHTUP = 0x10;
        private const int WM_MOUSEMOVE = 0x0200;

        private int Threshold = 20; //how far the mouse should move to reset timer
        private int StartLocationX = 0; //stores starting X value
        private int StartLocationY = 0; //stores starting Y value
        private Timer timerHold = new Timer(); //timer to trigger mouse click

        //Start Mouse monitoring by calling this. This will also set the timer.     
        private void StartFilterMouseEvents()
        {

            timerHold.Interval = 1000; //how long mouse must be in threshold.
            timerHold.Tick = new EventHandler(timerHold_Tick);
            Application.AddMessageFilter((IMessageFilter) this);
        }
        //Stop Mouse monitoring by calling this and unset the timer.
        private void StopFilterMouseEvents()
        {
            timerHold.Stop();
            timerHold -= timerHold_Tick;
            Application.RemoveMessageFilter((IMessageFilter) this);
        }
        //This will start when Application.AddMessageFilter() is called
        public bool PreFilterMessage(ref Message m)
        {
            if (m.Msg == WM_MOUSEMOVE)
            {
                if((Cursor.Position.X > StartLocationX + 20)||(Cursor.Position.X > StartLocationX - 20))&&
                       ((Cursor.Position.Y > StartLocationY + 20)||(Cursor.Position.Y > StartLocationY - 20))
                       {
                            timerHold.Stop(); //stops timer if running
                            timerHold.Start(); //starts it again with new position.
                            StartLocationX = Cursor.Position.X;
                            StartLocationY = Cursor.Position.Y;
                       }
            }
            return false;
        }
        //This event gets fired when the timer has not been reset for 1000ms
        public void timerHold_Tick(object sender, EventArgs e)
        {
            mouse_event(MOUSEEVENTF_LEFTDOWN | MOUSEEVENTF_LEFTUP, 0, 0, 0, 0);
        }

      }