[KPhotoAlbum] Assigning tags to groups

[Robert Krawitz]

On Sun, 15 Dec 2019 21:07:34 -0500 (EST), Robert Krawitz wrote:
> There are still problems with assigning tags to groups through the
> preferences dialog:
>
> 1) If you create multiple groups, then try to assign tags to those
> groups, the other groups you created immediately vanish from the
> left-hand panel.  This makes sense in a way, since those other groups
> don't (yet) have members, but it's a real annoyance.
>
> 2) More seriously, if you assign a tag to a group, and that tag is
> already under another group, that relationship is not removed,
> breaking the hierarchical relationship.  For example, with the demo
> database:
>
> * Create a group named "dk" under Denmark.
>
> * Assign Esbjerg to that group.
>
> * You'll find that Esbjerg belongs to both dk and Denmark.
>
> This does save out, leaving the member-groups looking like this:
>
>     <member-groups>
>         <member category="People" group-name="Pets" members="4,7,8"/>
>         <member category="Places" group-name="Denmark" members="12,2,4,8"/>
>         <member category="Places" group-name="USA" members="1,3,5,6,7"/>
>         <member category="Places" group-name="da" members="2"/>
>         <member category="Places" group-name="dk" members="2"/>
>     </member-groups>

It looks like the fixes -- when I can make my way through the code in
Settings/TagsGroupPage.cpp -- will be tricky.

The code seems to be assuming that there's a difference between a
group and a tag, where in fact a group is simply a tag that happens to
have children.  A group can have images directly containing it as well
as indirectly.  So we might need to show -- or at least have an option
to show -- every tag in the tree widget.

As for the multiple-parent issue, when I can figure out where the
relationship is being assigned it's still going to e tricky, because
the code operates on the real database, not a shadow copy.  So when
you click discard, the changes have to be undone.  That will be
interesting.

It's getting late, and I've already fixed one thorny bug today.
-- 
Robert Krawitz                                     <rlk at alum.mit.edu>

***  MIT Engineers   A Proud Tradition   http://mitathletics.com  ***
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