[Haskell-cafe] Projects that depend on the vty package?

[Magnus Therning]

On Wed, Dec 3, 2008 at 7:57 PM, Corey O'Connor <coreyoconnor at gmail.com> wrote:
> Hello,
> For further development of the vty package I'm really only paying
> attention to the requirements that fall out of the Yi project. Are
> there any other projects that depend on the vty package?
>
> In addition, the vty project has it's own wiki: http://trac.haskell.org/vty/
> Right now there isn't much information there but it is a great place
> to send bug reports or enhancement requests if you have them.

I haven't been using it for anything real, but I was playing around
with it in preparation for yet another project that hasn't taken off
(and it never might).  Anyway, it is a nice _low-level_ library, do
you have any plans on building convenient things on top of it?  Basic
widgets such as dialogues and lists spring to mind...

This is a rather pathetic list widget I came up with at the time:

module Main
    where

import Data.Maybe
import Graphics.Vty
import qualified Data.ByteString.Char8 as B

options = [ "01 Foo", "02 Bar", "03 Baz", "04 Qux", "05 Quux", "06
Quuux", "07 Foo", "08 Bar", "09 Baz", "10 Qux", "11 Quux", "12 Quuux",
"13 Foo", "14 Bar", "15 Baz", "16 Qux", "17 Quux", "18 Quuux", "19
Foo", "20 Bar", "21 Baz", "22 Qux", "23 Quux", "24 Quuux", "25 Foo",
"26 Bar", "27 Baz", "28 Qux", "29 Quux", "30 Quuux", "31 Foo", "32
Bar", "33 Baz", "34 Qux", "35 Quux", "36 Quuux", "37 Foo", "38 Bar",
"39 Baz", "40 Qux", "41 Quux", "42 Quuux", "43 Foo", "44 Bar", "45
Baz", "46 Qux", "47 Quux", "48 Quuux", "49 Foo", "50 Bar", "51 Baz",
"52 Qux", "53 Quux", "54 Quuux", "55 Foo", "56 Bar", "57 Baz", "58
Qux", "59 Quux", "60 Quuux" ]

main :: IO ()
main = do
    vt <- mkVty
    getChoice vt options >>= putStrLn . show

{-
 - List choice widget for Vty.
 -}
getChoice :: Vty -> [String] -> IO (Maybe (Int, String))
getChoice vt opts = do
    (sx, sy) <- getSize vt
    _getChoice vt opts 0 sx sy

_getChoice vt opts idx sx sy =
    let
        _calcTop winHeight listLength idx = max 0 ((min listLength
((max 0 (idx - winHeight `div` 2)) + winHeight)) - winHeight)
        _top = _calcTop sy (length opts) idx
        _visible_opts = take sy (drop _top opts)
    in do
        update vt (render _visible_opts (idx - _top) sx)
        k <- getEvent vt
        case k of
            EvKey KDown [] -> _getChoice vt opts (min (length opts -
1) (idx + 1)) sx sy
            EvKey KUp [] -> _getChoice vt opts (max 0 (idx - 1)) sx sy
            EvKey KEsc [] -> shutdown vt >> return Nothing
            EvKey KEnter [] -> shutdown vt >> return (Just $ (idx, opts !! idx))
            EvResize nx ny -> _getChoice vt opts idx nx ny
            _ -> _getChoice vt opts idx sx sy

render opts idx sx = pic {
    pImage = foldr1 (<->) $ map _render1 $ zip [0..] opts
    }
    where
        _render1 (i, o) = renderHFill attr ' ' 5 <|> renderBS (_attr
i) (B.pack o) <|> renderHFill attr ' ' (sx - 5 - length o)
        _attr i = if i /= idx
            then attr
            else setRV attr

/M

-- 
Magnus Therning                        (OpenPGP: 0xAB4DFBA4)
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