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3 commits

Author SHA1 Message Date
Berthold Stoeger
e7907c494f statistics: convert chart to QQuickItem
It turns out that the wrong base class was used for the chart.
QQuickWidget can only be used on desktop, not in a mobile UI.

Therefore, turn this into a QQuickItem and move the container
QQuickWidget into desktop-only code.

Currently, this code is insane: The chart is rendered onto a
QGraphicsScene (as it was before), which is then rendered into
a QImage, which is transformed into a QSGTexture, which is then
projected onto the device. This is performed on every mouse
move event, since these events in general change the position
of the info-box.

The plan is to slowly convert elements such as the info-box into
QQuickItems. Browsing the QtQuick documentation, this will
not be much fun.

Also note that the rendering currently tears, flickers and has
antialiasing artifacts, most likely owing to integer (QImage)
to floating point (QGraphicsScene, QQuickItem) conversion
problems. The data flow is
QGraphicsScene (float) -> QImage (int) -> QQuickItem (float).

Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>
2021-01-10 15:16:52 -08:00
Berthold Stoeger
7b0455b4d8 statistics: reverse chart selection logic
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>
2021-01-03 13:41:15 -08:00
Berthold Stoeger
165dce4a0e statistics: implement a statistics widget on desktop
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>
2021-01-03 13:41:15 -08:00