Allow a text label with scalebar

[Tristan Croll]

Tristan asks if the scalebar command could have an option to display a text label with the bar. Original request was in ticket #8837 which included a second problem, so this ticket is to separate the two issues.

[Tom Goddard]

It is a bit tedious to use the 2dlabel command to add a label near the scalebar. But there are so many desirable options for placing a label: font size, positioning relative to the bar, font family, font weight, text color. So adding a label is probably more complex than the entire current scalebar capability, and all the options are already available in the 2dlabel command. While it would be nice if all those were combined into the scalebar command I'd say that level of convenience so one command can be typed instead of two is probably not going to get implemented due to too many competing higher priority improvements.

[Tristan Croll]

(email reply from yesterday that didn't make it through):

The advantage of doing it that way is that the displayed value could be directly linked to the scalebar length, so the user doesn’t have to remember to manually synchronize them. Would also avoid needing to look up the Angstrom or micron symbols when those are the most appropriate units. You could always just set some reasonable default for font, size etc., then direct the user to use the 2dlabels command if they want to customize it.

[Tristan Croll]

The advantage of doing it that way is that the displayed value could be
directly linked to the scalebar length, so the user doesn’t have to
remember to manually synchronize them. Would also avoid needing to look up
the Angstrom or micron symbols when those are the most appropriate units.
You could always just set some reasonable default for font, size etc., then
direct the user to use the 2dlabels command if they want to customize it.

On Fri, 14 Apr 2023 at 19:06, ChimeraX <ChimeraX-bugs-admin@cgl.ucsf.edu>
wrote:

[Tom Goddard]

The automatic update of the scalebar length label is of course desirable. The main issue is whether we have time to add all the extra code to support it. In most publication figures the scalebar is unlabeled and the caption says how long it is. But I agree it would be nice to have an optional label.