The cursor is over your widget. If you consume this message, change the XPLMCursorStatus
value to indicate the desired result, with the same rules as in XPLMDisplay.h.
Return 1 to consume this message, 0 to pass it on.
Dispatching: Up chain
Param 1: A pointer to an XPMouseState_t struct containing the mouse status.
Param 2: A pointer to a XPLMCursorStatus - set this to the cursor result you desire.