[RFC PATCH] Add 'create new trip' option for downloading dives from the dive computer

[Jef Driesen]

On 2014-07-22 20:24, Linus Torvalds wrote:
> On Tue, Jul 22, 2014 at 11:11 AM, Dirk Hohndel <dirk at hohndel.org> 
> wrote:
> I'd say that the "private trip" is better than the Suunto DM3 dialog
> that Paul-Erik described. The private trip ends up being a similar
> kind of "preview dialog" for the newly downloaded dives, *but* with
> the advantage of being able to see the newly downloaded dives "normal"
> dives in subsurface (so you can view new and old dives together,
> delete the new dives you don't want, and the "download only new dives"
> vs "download *all* dives" parts of the downloading still works
> automatically etc). So it seems to be a good model. But not having
> ever used the Suunto DM thing, I don't know how the workflow differs
> and works in practice.

With a preview dialog, you can easily review the dives before importing 
them into your logbook. That makes it trivial to filter out unwanted 
dives. But you could also go one step further and indicate whether a 
dive would get merged into an existing dive or not. If for some reason, 
you don't like the proposed merge(s), you can still disable them before 
importing. I'm not sure how to do that with a private trip as the 
preview.

On the other hand, I like the fact you can view the newly downloaded 
dives immediately after the download in a normal way. With the private 
trip as the staging area, you get that feature for free, because it's no 
different from a normal trip.

Maybe we can implement something that satisfies both? Download the dives 
in the private trip, without automatically merging anything. And once 
the download has finished, present a dialog with the proposed merges. If 
the user is satisfied with the proposal, he can click the "accept" 
button to carry out the merges. If not, he can just cancel the automatic 
merge and the dives are left unchanged in the trip. With a more advanced 
UI you could even accept/cancel the proposed merge per dive.

Just like Paul-Erik, I would also prefer to have more control over the 
automatic merging. Right now it can be sometimes be very confusing. It's 
not the first time that after a download I wonder where the dives I just 
downloaded went. Did they merge or update data in another dive? Which 
dives are the newly downloaded dives?


BTW, using a preview dialog is not mutually exclusive with the download 
"all" vs "only new dives" feature.

The Suunto DM behavior might be a bit confusing here, due to how it 
downloads dives. The newer Suunto devices (vyper2 and d9 family) 
internally store their dives as a linked list. This allows the DM 
software to quickly retrieve the header of each dive and present a list 
with all dives. This gives the impression that it always downloads all 
dives, but that's not the case. It only downloads a summary, and the 
complete dives are downloaded later. Note that some other communication 
protocols also support this trick (e.g. OSTC3 and Petrel), but 
libdivecomputer doesn't expose this to applications on purpose, because 
not all protocols can support this.

Jef