After starting the year with curses work, I decided to do some more!
Currently we lack Soft Label Key functions as specified by POSIX. What are these? Glad you asked! Soft Label Keys ripoff a line from the bottom of the screen and allow for up to 8 keys to be displayed there. You can define labels for them, colours, etc.
“BIG WHOOP!” I hear you say. “My app already does this, why should I care?”
Because SLK also works with the terminfo database to work out if the terminal natively supports labels (via plab_norm, label_on, etc)! This means a line doesn’t have to be ripped off from the screen so no real-estate is lost. Sadly, no terminal actually seems to support these markings. But if one is ever made, it should work fine.
Now, not many curses apps actually use the SLK functions, probably for this very reason. But some do, and it is a standard so I’ve coded NetBSD to support this natively.
Sadly, this has uncovered a bug in the NetBSD curses library where cursor movement in a one line window at the bottom of the screen appears to push the window up. This is very visible with SLK and will have to be fixed for any apps that actually use it, but the SLK implementation itself is sound as resizing the terminal forces a redraw and it looks fine.