Called to handle keyboard events when this snip has the keyboard focus and can handle events. The drawing context is provided, as well as the snip's position in buffer coordinates, and the buffer's coordinates with respect to the event coordinates. The @link wx:event get-event-object method of event will return the top-level view (usually a wx:media-canvas% object) which received the event.
See also wx:const-snip-handles-events in get-flags.
To get event's x loaction in snip coordinates, subtract both x and mediax from (send event get-x).