To enable rudimentary theming, collect all colors in a new
theme class. The class has to be passed down to the various
items.
In general the items save a reference to the them in the
constructor. Alternatively, they might also just query
the StatsView everytime they need to access a color.
For now, it's hard the say what is preferred: a reference
per item or a function call per invokation?
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>
