Mouse wheel
Message generated when user rotates mouse wheel.
A1 [out,1u]A2 [out,1u]BX [out,4i]BY [out,4i]CX [out,4f]Message generated when user rotates mouse wheel. Only one wheel
is supported. CX contains relative change that should
be added to remembered scroll position. Unit of this value is a text
line.
Positive value means rotation forward (from the user) and negative value backward (to the user).