Sort Views to display Unconfirmed Faces together

[Maik Qualmann]

Hi Kartik,

We cannot do the sorting using the FaceTagsEditor. You have to assume that 
there are several thousand face items in the model. The model always compares 
whether an item has to be sorted in front of or behind. This would be tens of 
thousands of database accesses via the FaceTagsEditor. Under MySQL in 
particular, it would probably take a long time and the network traffic would 
be very heavily used. Therefore, almost all values are cached in the ItemInfo 
class.

Maik

Am Samstag, 13. Juni 2020, 08:33:11 CEST schrieb Kartik Ramesh:
> Hi Maik,
> 
> You're right that sorting faces needs info about the number of Unconfirmed,
> Confirmed faces. To get that I was using the
> FaceTagsEditor::unconfirmedFaceTagsIfaces
> <https://invent.kde.org/graphics/digikam/-/blob/master/core/libs/database/ta
> gs/facetagseditor.cpp#L67> (with a slight modification that it returns
> Unconfirmed Faces and not Unconfirmed+Unknown faces). This method takes in
> an ItemInfo and returns the list of Unconfirmed faces in that image.
> 
> I haven't yet committed to the remote repo. because I wasn't sure about
> this implementation, however I'll do that now, so that you and other
> mentors may have a look at this.
> 
> Kartik
> 
> On Sat, Jun 13, 2020 at 10:17 AM Maik Qualmann <metzpinguin at gmail.com>
> 
> wrote:
> > Hi Kartik,
> > 
> > To sort faces you need the information about confirmed and unconfirmed
> > faces
> > in the ItemInfo class. The ItemInfo class does not currently provide this
> > information. The sorting of faces must not affect the other views. Are the
> > latest sort changes already in the branch? I'll take a closer look at your
> > branch at the weekend.
> > 
> > Maik
> > 
> > Am Freitag, 12. Juni 2020, 14:17:57 CEST schrieb Kartik Ramesh:
> > > Hello all,
> > > 
> > > I was working on the next issue in my Project which is to modify sorting
> > 
> > of
> > 
> > > views so that all Unconfirmed Faces for any tag appear collectively
> > 
> > (either
> > 
> > > before or after) the set of Confirmed Faces. This enhances visibility
> > > for
> > > the user, and allows easy confirm/reject operations.
> > > 
> > > Sorting implementations for views are present in ItemSortSettings, so I
> > 
> > did
> > 
> > > a little modifications, and I've been able to sort the view as shown
> > > here
> > > <https://imgur.com/a/xODQfgj>.
> > > 
> > > However there's an issue with this, we're not sorting Faces but instead
> > > ItemInfos. Since every view (be it Albums view or People view) works on
> > 
> > the
> > 
> > > same model, this new sorting order will enforce changes on the other
> > 
> > views
> > 
> > > as well. I don't think it's possible for face A to appear before face B
> > 
> > but
> > 
> > > image A (which contains face A) appears after image B (please correct me
> > 
> > if
> > 
> > > wrong).
> > > 
> > > One way to fix this would be to implement a new Sorting role just for
> > 
> > this
> > 
> > > purpose. I also have some more fixes in mind but I would like to hear
> > 
> > other
> > 
> > > thoughts on this.
> > > 
> > > Kartik