From @mulby:

"I'm not sure exactly what's going on here, but I wonder if we can do this more generally? I would like to have something like a "edx.courseware.block.viewed" event that is emitted whenever any block is rendered.

Additionally, I'd like to put the usage_id in the xblock callback handlers so that we have this data available on every xblock related event (both rendering and processing).

Also note that for new events we are trying to move to a '.' separated naming convention. We would like to be able to do stuff like filter on 'edx.' to capture all edx emitted events, and 'edx.courseware.' to grab all courseware related events etc."