~alcinnz/fontconfig-pure

ref: 6e336e5ee4797190f83be2b381234980c7b680f5 fontconfig-pure/Graphics/Text/Font/Choose/FontSet.hs -rw-r--r-- 2.7 KiB
6e336e5e — Adrian Cochrane Define skeleton for parsing @font-face. 2 years ago
                                                                                
6e336e5e Adrian Cochrane
e21707cb Adrian Cochrane
b863f00d Adrian Cochrane
e21707cb Adrian Cochrane
db90fbd0 Adrian Cochrane
c10cdcf2 Adrian Cochrane
e21707cb Adrian Cochrane
c10cdcf2 Adrian Cochrane
e21707cb Adrian Cochrane
6e336e5e Adrian Cochrane
e21707cb Adrian Cochrane
c10cdcf2 Adrian Cochrane
e21707cb Adrian Cochrane
db90fbd0 Adrian Cochrane
e21707cb Adrian Cochrane
db90fbd0 Adrian Cochrane
e21707cb Adrian Cochrane
b863f00d Adrian Cochrane
e21707cb Adrian Cochrane
b863f00d Adrian Cochrane
e21707cb Adrian Cochrane
db90fbd0 Adrian Cochrane
e21707cb Adrian Cochrane
c10cdcf2 Adrian Cochrane
e21707cb Adrian Cochrane
c10cdcf2 Adrian Cochrane
b863f00d Adrian Cochrane
6e336e5e Adrian Cochrane
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{-# LANGUAGE OverloadedStrings #-}
module Graphics.Text.Font.Choose.FontSet where

import Graphics.Text.Font.Choose.Pattern
import Graphics.Text.Font.Choose.Result (throwFalse, throwNull)

import Foreign.Ptr (Ptr, castPtr, nullPtr)
import Foreign.Storable (pokeElemOff, sizeOf)
import Foreign.Marshal.Alloc (allocaBytes)
import Foreign.Marshal.Array (peekArray)
import Control.Monad (forM)
import Control.Exception (bracket)

-- For CSS bindings
import Stylist.Parse (StyleSheet(..), parseProperties)

type FontSet = [Pattern]

------
--- Low-level
------
data FontSet'
type FontSet_ = Ptr FontSet'

withNewFontSet :: (FontSet_ -> IO a) -> IO a
withNewFontSet = bracket fcFontSetCreate fcFontSetDestroy
foreign import ccall "FcFontSetCreate" fcFontSetCreate :: IO FontSet_
foreign import ccall "FcFontSetDestroy" fcFontSetDestroy :: FontSet_ -> IO ()

withFontSet :: FontSet -> (FontSet_ -> IO a) -> IO a
withFontSet fonts cb = withNewFontSet $ \fonts' -> do
    forM fonts $ \font -> do
        font' <- patternAsPointer font
        throwFalse <$> fcFontSetAdd fonts' font'
    cb fonts'
foreign import ccall "FcFontSetAdd" fcFontSetAdd :: FontSet_ -> Pattern_ -> IO Bool

withFontSets :: [FontSet] -> (Ptr FontSet_ -> Int -> IO a) -> IO a
withFontSets fontss cb = let n = length fontss in
    allocaBytes (sizeOf (undefined :: FontSet_) * n) $ \fontss' ->
        withFontSets' fontss 0 fontss' $ cb fontss' n
withFontSets' :: [FontSet] -> Int -> Ptr FontSet_ -> IO a -> IO a
withFontSets' [] _ _ cb = cb
withFontSets' (fonts:fontss) i fontss' cb = withFontSet fonts $ \fonts' -> do
    pokeElemOff fontss' i fonts'
    withFontSets' fontss (succ i) fontss' cb

thawFontSet :: FontSet_ -> IO FontSet
thawFontSet fonts' = do
    n <- get_fontSet_nfont fonts'
    array <- get_fontSet_fonts fonts'
    if n == 0 || array == nullPtr
    then return []
    else do
        list <- peekArray n array
        forM list (thawPattern . throwNull)
foreign import ccall "get_fontSet_nfont" get_fontSet_nfont :: FontSet_ -> IO Int
foreign import ccall "get_fontSet_fonts" get_fontSet_fonts :: FontSet_ -> IO (Ptr Pattern_)

thawFontSet_ :: IO FontSet_ -> IO FontSet
thawFontSet_ cb = bracket (throwNull <$> cb) fcFontSetDestroy thawFontSet

------
--- CSS Bindings
------

data FontFaceParser a = FontFaceParser { cssFonts :: FontSet, cssInner :: a}

instance StyleSheet a => StyleSheet (FontFaceParser a) where
    setPriorities v (FontFaceParser x self) = FontFaceParser x $ setPriorities v self
    addRule (FontFaceParser x self) rule = FontFaceParser x $ addRule self rule

    addAtRule self "font-face" toks =
        let (props, toks') = parseProperties toks in (self, toks')
    addAtRule (FontFaceParser x self) key toks =
        let (a, b) = addAtRule self key toks in (FontFaceParser x a, b)