[ENH] Reimplementation of OWChoropleth

[robertcv]

Issue

The old OWChoropleth widget is based on a javascript library and is running in a WebviewWidget. As a result, it has a lot of hard to debug problems.

Description of changes

Implemented an OWScatterPlotBase like plot class for dawing choropleth and maps. Update widget style to a more modern look.

This is a working version for testing. Bugs may occur. Open to suggestions for small enhancements.

TODOs:

• rebase after [ENH] Move map plot utils to separate file #91 is merged
• number of color buckets
• fix discret colors to be the same as agg_attr -> scatterplot doesn't support it
• add caching
• add settings migration
• fix tooltip
• add selection saving
• add support for time data

Includes

• Code changes
• Tests
• Documentation

[robertcv]

@ajdapretnar @AndrejaKovacic take a look :)

[ajdapretnar]

I propose switching automatically to 'mode' when discrete attribute is selected for the first time. And disabling all aggregations that don't apply.

[AndrejaKovacic]

Tooltip is nice, but i think it should also include the exact values of what is being plotted for the region.
E.g.: Sum (attribute): 3456

[codecov-io]

Codecov Report

Merging #89 into master will increase coverage by 15.42%.
The diff coverage is 81.12%.

@@             Coverage Diff             @@
##           master      #89       +/-   ##
===========================================
+ Coverage   68.33%   83.75%   +15.42%     
===========================================
  Files           9        9               
  Lines        1197     1607      +410     
  Branches      168      236       +68     
===========================================
+ Hits          818     1346      +528     
+ Misses        341      200      -141     
- Partials       38       61       +23

[robertcv]

This is now incompatible with old releases of Orange due to the changes of color palettes on Orange master.

[janezd]

1. Connect File -> Choropleth.
2. Select some regions.
3. Connect Choropleth to another Choropleth. Column "Selected" does not appear because you connected "Selected data", not "Data"
4. Double click the connection and connect "Data" instead. Column Selected still doesn't appear.
5. Ask @VesnaT how to fix this. Perhaps see Scatter plot does not detect coloring changes orange3#4391 and [FIX] DataProjectionWidget: Update combos on new data orange3#4405, if this is a similar problem.

[janezd]

Would it be possible to put names above colored polygons?

[janezd]

Nice.

I've clicked around and experienced no crashes. But perhaps this widget needs to be thouroughly clicked through by somebody who already used it and know practical use cases.

I reviewed the code, except the parts related to maps, about which I don't know much. I/We will have to trust you on this.

It would be great if you added more tests, but I won't object if you don't.

[robertcv]

Would it be possible to put names above colored polygons?

While possible to show maps without names and overlaying them on top of polygons, it is a lot of work. I wouldn't implement it in this pr.

[janezd]

Would it be possible to put names above colored polygons?

While possible to show maps without names and overlaying them on top of polygons, it is a lot of work. I wouldn't implement it in this pr.

OK, understood.

[robertcv]

@janezd I changed the attr-agg handling to reflect the suggested changes. This should now be the final version if no additional issues are found. Now I just don't know what to do with new pallets since there is no new Orange release. Perhaps this can be merged but then we withe for new geo addon release.

[janezd]

I think you can merge this, but wait with the release.

[janezd]

κῦδος for this monumental work!

I'm merging it now, but the release has to wait for the release of Orange.