RFC: Statistics in Subsurface

[Dirk Hohndel]

Hi Willem,

adding the Subsurface developer list to this thread

> On Sep 27, 2020, at 5:34 AM, Willem Ferguson <willemferguson at zoology.up.ac.za> wrote:
> 
> A quick question about the use of C++ and QML in writing code for presenting graphs. In general, my leaning is towards QML simply because making anything mobile-friendly is a longer term investment, even though I hate QML. But there are at least four parts of the code that may benefit differently from QML:
> 
> 1) UI for selecting variables to be plotted. At this stage just two comboxes as discussed in previous emails during May this year. This could benefit from QML , but the UIs on desktop and mobile are likely to differ vastly. Therefore doing it in QML may not necessarily yield tangible benefits and one may just as well do it in C++ for the desktop. Comments?

The more I think about this, the less I think it makes sense for this to be in QML on the desktop. Yes, it will need a QML UI on mobile if we decide to allow editing on mobile - but part of the reason why we are storing those filters in the cloud storage is so that we don't need that UI on mobile in the first place. Because: painful, complex, error prone on a small touch screen
So I'm fine with what Berthold has started, just using QWidgets

> 2) Background infrastructure for creating arrays/structures/linked-lists to be plotted. This interacts with the dive_table structure, extracts appropriate information, creates appropriate categories (e.g. when plotting values associated with tags). This should probably be in C++ since no UI is involved and I cannot see why QML would be beneficial. Is this point of view realistic?

Definitely. And I think Berthold is planning to write that code.

> 3) The graphing that occurs within a single graphview object. This should probably be beneficial if it were written in QML, since it would be portable to the mobile environment. Porting this to mobile might mean rewriting the UI frame/page/tab to place the graph at an appropriate place, but the way the graph is constructed will be standard across desktop and mobile. Is this point of view realistic?

Yes - if we can use the same QML code on desktop and mobile for actually creating the graphs, that would likely be best.

Curious if others have strong feelings about this...

/D