Investigate alternative backend

[gyscos]

Ncurses is nice, but is pretty much terrible.

Intersting alternatives currently include rustty and termion.

First step would be to remove references to ncurses types from the public API (there's not a lot left).

[ticki]

Author of Termion here. You said right here, that it lacked of certain features, and I'd be happy to implement those. Could you give me a list of what you need?

[gyscos]

The exhaustiveness of input detection was really the main one I was thinking about, but maybe it's not a problem - I'll start working a bit on the port to see how it goes.

[ticki]

Feel free to ping me as you encounter issues.

[gyscos]

All ncurses-specific code has now been isolated in a Backend trait, making its replacement easier.

Currently missing from Termion to achieve feature parity:

• Check if the current terminal support colors (for easy fallback on linux console)
• No function to redefine the default 216 colors palette (they should be able to accept any 24bit color).

[ticki]

Thanks! I'll add those.

[gyscos]

Also:

• A timeout-able event polling (like the one from rustty) to read for events without blocking entirely.
  • AsyncReader only gives a Read interface, it doesn't output Keys.
• (Less critical) A way to directly create a Color from its ansi code (especially if the palette is not the default one).

[ticki]

AsyncReader only gives a Read interface, it doesn't output Keys.

It does! Read gives you TermRead for free.

[gyscos]

Oh - I think I've been reading an outdated doc for some time.
Too bad keys is only for nightly though - I'll wait a bit to see how the stabilization goes.

[ticki]

Yeah, keys requires nightly for now. I believe char will be stabilized in only a few weeks.

[ticki]

No function to redefine the default 216 colors palette (they should be able to accept any 24bit color).

You cannot exactly redefine it, but a way to use truecolor will certainly be interesting. I will add that one of the days.

A timeout-able event polling (like the one from rustty) to read for events without blocking entirely.

There is a RFC adding timeout recv to mpsc. This can be added whenever that RFC is merged.

(Less critical) A way to directly create a Color from its ansi code (especially if the palette is not the default one).

This is added. http://ticki.github.io/termion/color/struct.AnsiValue.html

cc. myself @ticki

[ticki]

You mentioned this in the reddit thread. Is there anything new? I've added truecolor. Is there anything else that you need to complete this?

[gyscos]

#59 was blocking this, now that it's closed I'll start experimenting again on a termion backend.
The only detail I see will be a regression in supported input, as it seems termion only supports modifiers for characters, not for special keys (ctrl-shift-left, alt-F3, etc.).

[ticki]

Special keys are much harder to have identifiers for. There's no standard for those, and I'm not sure exactly if it's even possible...

[gyscos]

Ncurses somehow manages to get it, at least on most terminal emulators (actual TTYs seem more limited) - examples/key_codes.rs can detect a wide range of modifiers on most common terminals.
The problem is that termion discards unrecognized bytes as errors, which means the application does not have a chance to do its own (non-universal) parsing.

[ticki]

The problem is that termion discards unrecognized bytes as errors, which means the application does not have a chance to do its own (non-universal) parsing.

That's a good pont...

[gyscos]

ad7606c adds an initial termion backend.
It is in a very early state and is currently very far from being usable, as it lacks input, colors, and probably many other things.

[ticki]

@gyscos It seems that you forgot to commit a file (termion.rs)?

[gyscos]

It is present: https://github.com/gyscos/Cursive/blob/master/src/backend/termion.rs

To use the termion backend, you need to use the termion feature and remove the default features.

[ticki]

ah

[gyscos]

Alternative backends have been investigated.
Termion support is still incomplete, but the bare minimum works. Specific issues will get their own tickets.

[ticki]

Cool!

[ticki]

Could you open said issues or list them here? I'm interested in helping if I can (this library is nice, and it'd be cool to have e.g. Redox support, which Termion provides).

[Ameobea]

@ticki I'm using Termion as a backend for my application and it's been working perfectly so far. Thanks for your hard work making this compatible and on Termion in general!

[ticki]

@Ameobea To be fair, @gyscos has helped a lot as well!