void OnEvent (wxMouseEvent& event)
Handles mouse input to the buffer. The default method either passes this event on to a caret-owning snip or calls OnLocalEvent. Override this method for your own use, but consider overriding OnLocalEvent or OnDefaultEvent instead.
The eventObject member of event will be set to the top-level view (usually a wxCanvas object) which received the event. The event's x and y coordinates are in the view's co-ordinate system; use the administrator's GetDC to obtain translation parameters.