Bug: Cylinder editor doesn't honor sorting

Dirk Hohndel dirk at hohndel.org
Sun Dec 11 15:20:10 PST 2011

On Dec 11, 2011, at 3:00 PM, Linus Torvalds wrote:
>> So I left it alone for now - some day we could use some fancy cell
>> renderer to show multiple cylinder information [...]
> Ok, so that "some day" is today.

Time, it passes so fast some times...

> This involved adding a custom sort function to the whole divelist
> column mix, and that in turn required some setup changes to make it
> clean enough, but it wasn't all *that* complicated. The end result may
> be buggy, but it works in my testing, and looks reasonable.
> So what happens now is that if you have trimix dives, the O2% column
> will look like
>    21/30
> or similar, where the first number is Oxygen, and the second is
> Helium. So the above would be an example single gas cylinder for deep
> traveling (21% O2, 30% He).

Umm. Can we rename the column then, please? Having 21/30 as my 
"O2 value" really makes no sense at all. 
And then we need to be somewhat consistent so sorting makes sense?
So air would become "21/0" and EAN36 "36/0"?

> But if you have multiple tanks, we'll show the maximum percentages
> (per gas), so if you have a 50% Oxygen cylinder for your deco stop,
> and a 70% Helium cylinder with 10% Oxygen for your deep phase, we'll
> show
>    50/70
> for the mix, even though at no point did you obviously ever breath
> *that* particular mix (getting 50% oxygen and 70% Helium into one
> cylinder would be tricky just from a physics standpoint, never mind
> the diving insanity of having a high-O2/high-He combination). But from
> a "dive summary" standpoint, I think it makes sense to show the
> maximum O2/He contents, even if they were in separate cylinders.

I don't have a basis to disagree. But I think we know a couple of tech 
divers whom we could ask what THEY would like to see. Since neither
is on this mailing list I'll ask them off list and copy you.

> Because they show up in one column, it also requires some kind of
> complex sorting. I made the rule simple: trimix is manlier than
> nitrox, so even a low Helium percentage will sort as "bigger" than a
> high Oxygen percentage.
> So 21/70 > 30/30 > 50, even if the actual amount of oxygen is the
> other way around. A higher He value will always sort higher, so even
> if you were to just do some crazy "air with just 1% Helium", that
> would sort higher than some pure oxygen deco bottle.
> Basically it means that your trimix dives will always sort separately
> from your other dives.

Ah - this is your way around the issue that I mentioned above.
I think I can live with that - it still begs for a better column header, though.


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