nucleotides ladder: limit to only displayed residues?

[Elaine Meng]

When I only have certain residues displayed (residues 3 and 22 in 1bna), “nuc slab” and “nuc tube” work to only show nucleotide representations for those residues, but “nuc ladder” shows rungs for all of the nucleotide residues in the structure. Since it’s possible to show only the rungs for those residues (e.g. command “nuc :3,22 ladder”) shouldn’t “nuc ladder” only show rungs for :3,22? I understand it’s slightly different because they might be H-bonding to other residues, but maybe it could implicitly consider only the displayed residues, as if you’d specified them in an atomspec (“nuc ladder” = “nuc <displayed-residues> ladder".

[Greg Couch]

Fixed. Only show ladder if ribbon or C3' displayed.

[Elaine Meng]

That’s an improvement, but if you wanted ladder to behave like slab and tube/slab, it would only look at C3’ (not get displayed if only ribbon were shown).  My test case was showing the whole ribbon but only the atoms for a single base pair, used to make the ChimeraX nucleotides feature highlight.
http://www.rbvi.ucsf.edu/chimerax/features.html#nucleotides

[Greg Couch]

Fixed. Also fixed bug where adding nucleotides after removing all previous ones caused a backtrace.

[Greg Couch]

Changed so that ladder is only displayed if C3' is displayed. This makes all of the nucleotide abstractions only dependent on whether or not atoms are displayed. The ribbon does not count.