[tracecompass-dev] Proposal for a way of working with views and viewers

[Matthew Khouzam <matthew.khouzam@xxxxxxxxxxxx>]

pre-emptive tl;dr - make the viewers less smart and re-usable.

Hi all, I am proposing a new architechture for Oxygen. I wish I had time
before the feature freeze of neon, but let's face it, that won't happen. :)
 
Right now we have views and viewers. All (most) of our views are
TmfViews. What is a TmfView? Something that can be time aligned and
pinned. Not much else.
 
What is a viewer? it is a super-powered item that contains a lot of
logic pertaining to traces and analyses.
 
What is a trace? a container of events.
 
What is an analysis? something that does something something...
 
The good news is, I think we got the trace's role down perfectly.
 
Here's a new repartition of responsibilities I propose.
 
The view: has a notion of the trace, has all the signal handlers.
Notifies its viewers and supplies viewers with analyses, never the trace.
 
The analysis: has all the information necessary to populate the trace.
This has a view model and the logic to fill it.
 
The viewer: (reduced responsibility) gets an analysis and refresh
signals and updates its data with these signals and model.
    The viewer( or later the viewer content provider?) must advertize
the moduleIds it needs.
 
The trace: stays the same.
 
This should reduce the view-viewer coupling, and allow for a more
modular way of integrating viewers into views.
 
Prototype for TmfView:
 
TmfView{
    private trace;
    public signalhandlers; // updates the viewers and the initial state.
    private Viewer viewers; // or a collection?
}
 
Analysis{
    String ID;
    doIt(); // schedule and execute
    getOutput;
}
 
Viewer{
    String getModuleId();
    update(analysis);
}
 
Trace{
    // same
}
 
This would be a HUGE change IMO, but would make the code more
extendable, testable, and also make sense of why we have a view and
where what code goes. At this moment, we have the viewer and the view
playing with the trace and the analysis. This is looking for trouble.

tl;dr - make the viewers less smart and re-usable.

Thoughts?