[lmi] Editing cell classes in census view

[Vadim Zeitlin]

 Hello,

 As discussed recently in private emails, I think that editing cell classes
in lmi UI is currently too implicit which is not ideal from the usability
point of view. To be more precise, the fact that classes don't explicitly
appear in the UI anywhere other than in the value of the corresponding
column means that:

1. There is no way to see all currently defined classes. Even for a small
   census scanning the column values is not very simple, but for a large
   one it's simply impossible.

2. There is no way to edit the given class directly, first a cell belonging
   to it must be located and selected. This is, again, mostly a problem for
   the big censuses but is not very user-friendly even for the small ones.

3. There is no way to directly create a new class. This has to be done by
   creating a new cell and entering the new class name into it and keeping
   in mind that all the changes done to the new cell will become part of
   the new class while none of the changes done to this cell later will
   affect it. While logical, this behaviour is not immediately obvious.

4. Editing a class can be used to rename it or overwrite another class by
   changing the class name while editing it. This is probably intentional,
   but still somewhat surprising.


 I don't know if any of the above are really problems in practice. IMHO, if
the classes are used at all, and used for big censuses, than at least (1)
and (2) should be, but I could be wrong, of course, which is why I won't go
into details of the solution I would propose for fixing them -- as this is
not going to be useful if we don't need to fix anything. But, in short, my
idea was to make the classes explicit in the UI, i.e. provide (sub)menu
commands for managing them and GUI controls for viewing/editing/adding
them. If this is deemed desirable at all, I'd need to know more about how
classes are used, i.e. what is the relative importance of providing fast
access to the operations for creating and editing them (i.e. are they often
created and almost never edited afterwards, or, on the contrary, often
edited after creation?) and how many classes would there typically be
(managing 1-10 of them needs different UI approach than managing a
hundred).

 Please let me know if you think it's worth pursuing this topic and, if it
is, whether do you have any information about how the classes are used by
lmi users currently.

 Thanks in advance,
VZ