Just add the
WMMouseWheel and
WMMouseHWheel message handlers and in them call the method responsible for scrolling the component using the keys.
procedure WMMouseWheel(var Message: TLMMouseEvent); message LM_MOUSEWHEEL;
procedure WMMouseHWheel(var Message: TLMMouseEvent); message LM_MOUSEHWHEEL;
Check what the
Messsage argument has, recognize horizontal/vertical direction and, on the basis of recognized direction, pass the appropriate key constant (in the form of variable) to the
KeyDown method. Or simply modify the component code (without inheritance), copy the parts of the logic from the
KeyDown method to the message handlers and that's it.
I don't know this component, I've never seen or used it, but it should work fine.