I have ẞ (Germandbls), both, uc and sc.
When I check sc fea in Glyphs everything is ok; Straße became S/t.sc/r.sc/a.sc/germandbls.sc/e.sc
but when I change lc to sc in InDesign it change it to Strasse?
And when changing Straße to all caps it became STRASSE
That is okay because this is what a German-speaking user will expect. Why? Because, according to the official orthography, ß has no uppercase, and when writing in all-caps (or all-smallcaps), must be replaced to SS.
Officially, the uppercase Germandbls is merely a ß that fits to uppercase letters (cap height instead of ascender, color, etc.). But there has been a century-old discussion about introducing it to the official orthography as well.
If you have a weekend to spare, you will find plenty of articles about it all over the web.
True. You could add it to the case code, which would trigger the cap sharp S whenever the user chooses all cap text in InDesign. It would not catch the case where a user just types with the Shift key held down.
A different solution to which the Typejockeys pointed me is to change the contextual substitution to react to a cap after the sharp s, rather than the sharp s between two caps. This would catch your case as well, no matter how they user produced the all-cap text.
Only difference – case also reacts with “Adobe Einzeilen/Absatzsetzer” (Standard in german Indesign) while calt only reacts works with the “Globaler Einzeilen/Absatzsetzer”. (Or maybe I am missing something here) Either way, is there any reason to not just do all three things? A case version, a calt version, and the code you suggest plus the Typejockey solution?
calt should work in both composers. (Just tried again, and the sharp S replacement works in both in CC 2019.) I believe certain lookup types don’t work in the legacy composer, like chaining contextual, but this is not the case here. ccmp is ignored in the legacy composer.
I have another follow up question about the .case version.
There is a case (and I know this might be very very rare…) where a germandbls.case (that is a component glyph of Germandbls) would be good is: «Aß sie etwas?» in All Caps. With the calt feature, this cannot substitute (otherwise we make «Aẞ sie etwas?» happen).
Is your advice to disregard this case, use germandbls.case, or do you have another solution for this?
Actually this should be a job for the layout engine. But it will still take time until the new orthography has trickled into all software.
In the case of Adobe perhaps even years, because I assume they are reluctant to invest into updating all their TypeKit fonts. And they would not want to add a feature that their own fonts do not support.