Improve the display of interbase data like insertions in SNPCoverage

[alpapan]

v2.15.4 with microsoft edge

when viewing an alignment track with combination plot, the tooltip for the snpcoverage becomes misaligned for inversions.
deletions and other variants are fine, just deletions. happens in 2 zoom levels at least.

Please see video here
https://nextcloud.stressedfruitfly.com/s/WRSag3A8kQ33MwE

[cmdcolin]

I think you mean insertion and not inversion?

Also I think that it is displaying what is "expected" right now, though I know it is not ideal

Insertions are an "interbase" operation (you insert one or more letters between two positions)

However the tooltip is not really setup to render interbase stuff that well so the insertion counts are tallied up "to the right" of the insertion. That might be what you observe about it being "misaligned"

The fact that these purple blocks are "thick"and have a count on them is just a thing jbrowse does to indicate insertions greater than 10bp. That particular range the thick purple blocks cover is technically between the bases (inter base)

We could consider doing some adjustment to make some of the above more clear