For some chart (e.g. pie charts or stacked bar charts), we want
to display a legend. QtCharts' legend interface happens to be
private and therefore is of no use.
This introduces a legend box which is implemented using
QGraphicItems, which can be placed on top of QCharts. It's very
unfancy, but works for now. If there are too many items, not
all are shown. Currently, the legend is configured to fill
at most half of the width and half of the height of the chart.
This might need some optimization.
Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>
Add a source file and a header file, which implement the color
scheme used by the statistics module.
Besides a few color constants, the centerpiece is a
function that returns the color representing a bin and
an appropriate label color. It picks a roughly equi-distant
set of colors out of an already balanced set of 50 candidate
colors. And it also picks white as text color when adding a
label to a segment with a dark color.
The color list was created using a tool by Gregor Aisch that
is available on GitHub as https://github.com/gka/palettes to
create multi-hued, multi-stop color scales that are safe for
color blind people.
This commit contains code from three authors.
Dirk (main author): adaptive color scheme.
Willem: Colors of single-bin charts and lines.
Berthold: Infrastructure.
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
Signed-off-by: willemferguson <willemferguson@zoology.up.ac.za>
Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>
The StatisticVariable class hierarchy encapsulates the concept
of a dive-variable, which can be plotted in charts either as
dependend or independend variable.
There are three types of these variables:
1) discrete: For example dive buddies or suit type.
2) continuous: Has a notion of linear metric - can be
used as histogram or scatter plot axis.
3) numeric: Like continuous, but allows for operations
such as calculating the mean or the sum over numerous
dives.
All variables support binning. The bins are defined per
variable.
Continuous variables can be converted into an arbitrary
double value, which is used to be plotted on a continuous
axis.
Moreover, numeric variables support a number of operations,
which depend on the variable.
Since binning is based on different types, the code is rather
template-heavy. Of course, this could be solved with
unions/variants and runtime-polymorphism, but using templates
was just much quicker. Notably, this uses the CRTP
(curiously recurring template pattern) where a subclass
passes itself as argument to the baseclass. This is a weird
kind of "reverse inheritance".
The StatsTranslations class is a dummy class which will
be used to collect all translations of the statistics
module.
This includes changes by Dirk to fix compilation of the
downloader.
Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
