Dynamic table of lat/lon on path/polygon elements about earthsim HOT 3 CLOSED

Can anyone weigh in on my approach to this? If the annotators get generalized, the direction of my approach may change completely.

from earthsim.

This will require some consideration, particularly considering potential refactors/changes to the Annotators. The main obstacle here and elsewhere will be whether we can find a nice mechanism to share datasources between the polygon datastructure and the annotated values. Currently the main complexity in the PolyAnnotator, which is not shared by the PointAnnotator is that we have to manually sync the labels and the polygon/polyline data with the associated labels, while the point data can simply share the same underlying data source.

This is because the mechanism used by HoloViews to share datasources is to check whether the .data attribute on the elements has the same identity, which is no problem for Points and Table but is currently not entirely straightforward for Polygons/Path elements and a Table.

Once we have solved that problem we should fairly easily be able to display the full set of lat/lons or add some additional column that describes the lats/lons for each polygon/line.

from earthsim.

... this is because the mechanism used by HoloViews to share datasources is to check whether the .data attribute on the elements has the same identity

This has generally worked better than I expected but maybe we should consider a way to extend this mechanism as required in HoloViews. The core of it is a boolean predicate to decide whether something 'is the same thing' or not.

from earthsim.