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

11 Dec 2008

      On Wed, Dec 3, 2008 at 7:57 PM, Corey O'Connor  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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