The 'onMouseMove' callback

Event number: 15
Generated for: Any visible control

A Mouse Move event is generated when the user moves the mouse over a control. The event-specific parameters in ⎕EV are (in index origin 1):

        ⎕EV[6]         Mouse vertical position in window pixel coordinates
        ⎕EV[7]         Mouse horizontal position in window pixel coordinates
        ⎕EV[8]         0
        ⎕EV[9]         Modifiers:
                       (0=unshifted, 1=shifted, 2=alt/option,
                       4=control, 8=command, and sums thereof)