Re[2]: [lmi] Allow direct drill-down editing in census manager

[Vadim Zeitlin]

On Tue, 16 Mar 2010 21:06:57 +0000 Greg Chicares <address@hidden> wrote:

GC> > There's tons of fields in cell editor;
GC> 
GC> I counted them once; I think their cardinality approaches 2^8,
GC> which might be a built-in limit on a grid control's columns.

 FWIW there is no limit for the number of columns in wxGrid. There might be
a limit in the native wxHeaderCtrl which the grid may optionally use and
that both wxListCtrl and wxDataViewCtrl always use but if there is one I
can't find it in the Microsoft documentation and it would be easy enough to
allow to use the generic implementation of wxHeaderCtrl with wxDataViewCtrl
if needed (the native one looks slightly better but the generic one is
perfectly functional and in fact wxDataViewCtrl used to use it before the
native one became available).

 For me the interesting question is whether we may need to have non-flat
structure of the rows in this control, i.e. whether it may make sense to
organize them in tree- or forest-like structure and allow the user to
collapse the branches that are not relevant. If not, then either wxGrid or
wxDataViewCtrl would do. wxGrid has the advantage of being completely
generic and so allow just about anything you may need but it is limited to
a flat 2D array of cells unlike wxDataViewCtrl. wxDataViewCtrl also looks
better, especially under non-MSW platforms (it doesn't have native
implementation for the main part of the control under MSW), but the main
reason to choose it would be to be able to allow for hierarchical
structure.

 Anyhow, to summarize, I think that wxDataViewCtrl is probably the most
suitable one for the purpose of the task at hand but wxGrid could
definitely be also used. wxListCtrl has several big limitations compared to
these controls, e.g. it only allows to edit the first cell of any row in
place. But I don't know which, if any, of them really matter so maybe there
is no need to switch the GUI control used at all.


GC> That's what led me to the idea of displaying only columns that
GC> aren't actually the same across all rows. New users are mystified
GC> at first, but that only lasts a minute; once they understand it,
GC> they think it's natural enough that they don't ask us to change it.
GC> If everyone lives in California, then how could the US-state field
GC> hold any interest? If people of both genders are included, then
GC> how could gender not be significant enough to show?

 I wanted to check how did this work in practice (especially if there was
any way to see the fixed values of all the not shown columns) but I
couldn't actually find it. Sorry in advance for the stupid question but
what exactly should I do to see/edit this grid? Is this the same one I see
when I do "Open" or "New" "census"? If so, I guess I need some more
complete data files [than sample.cns] to see anything interesting in it.
But maybe I'm looking in a wrong place?

 Thanks,
VZ