The range for a one-bin chart is [-0.5,0.5], thus the range
in an n-bin chart is [-0.5,n-0.5], not [-0.5,n+0.5].
Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>
The grid is based on the axis ticks. If labels in histogram
axes were skipped (because there are too many bins), it could
happen that the grid was incomplete, because the first and/or
last tick were missing. Add these explicitly.
Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>
The coordinates of these were calculated when creating the feature.
This is wrong, because the min/max values of the axes can change
on resize to get "nice" number. Therefore, recalculate after resizing.
This means that the general "LineMarker" class has to be split into
two classes, one for regression lines and one for median/mean
markers.
Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>
Easy enough to implement, but one weirdness:
To get the height of the rotated text, one has to access the
width() member of the boundingRect. I'm not sure if that makes
sense, but so be it.
Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>
Replace by custom implementation, with the ultimate goal to
remove the QtCharts module. This doesn't yet display axis
titles or a grid.
Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
The chart was passed as argument to the function recalculating
the axis labels. Instead, pass the chart in the constructor of
the axes and save it. This gains us flexibility for the future:
There will be more functions that need to access the chart (e.g.
resizing of the axes).
Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>
Implement five kinds of axes:
- ValueAxis: a standard axis for plotting numerical linear data.
- CountAxis: a ValueAxis for plotting counts of dives.
- CategoryAxis: an axis for plotting discrete variables without
any notion of distance.
- HistogramAxis: an axis for plotting bins with a numeric value.
- DateAxis: a HistogramAxis that formats dates.
The axes derive from a common virtual base class that defines
a small interface, notably, returning the minimum and maximum
displayed value and redrawing the axis.
The mapping and painting is performed by QtCharts' axes. On
the one hand, using QtCharts turned out to be too inflexible.
On the other hand it allowed us to quickly prototype the charts.
Ultimately, we should do our own drawing of the axis.
As a testament to the inflexibility, QtCharts' axes do not
allow for repeated labels is needed for quarter-based date
charts (year, Q2, Q3, Q4, year, Q2, Q3, ...). Therefore the
code disambiguates labels by adding unicode zero-width spaces.
Wonderful.
When omitting labels due to space reasons, the histogram
axis attempts to show "preferred" labels. In the quarter
example above, it tries to show full years.
Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>
