The old ways was to select the chart first, then depending on
the chart choose the binning.
Willem says that it should work the other way round: select
the binning (or operation) and make the charts depend on
that.
I'm not arguing one way or the other, just note that the new
way is much more tricky, because it is easy to get unsupported
combinations. For example, there is no chart where the
first variable is unbinned, but the second axis is binned
or has an operation. This makes things distinctly more tricky
and this code still needs a thorough audit.
Since this is all more tricky, implement a "invalid" chart
state. Ideally that should be never shown to the user, but
let's try to be defensive.
Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>
Implement a widget that shows the statistics state as comboboxes
and the statistics chart. Calls into the statistics code if any
of the comboboxes changes.
The hardest part here is the formatting of the charts list with
its icons and with headings. Sadly, it is not trivial to arrange
icons horizontally. Therefore we would have to fully reimplement
the ComboBox view, which is probably not fun.
Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>
