Refactoring: Xmobar.X11

1 files changed, 129 insertions, 0 deletions

diff --git a/src/lib/Xmobar/X11/XUtil.hs b/src/lib/Xmobar/X11/XUtil.hs
new file mode 100644
index 0000000..6e9eb2b
--- /dev/null
+++ b/src/lib/Xmobar/X11/XUtil.hs
@@ -0,0 +1,129 @@
+{-# LANGUAGE CPP #-}
+
+-----------------------------------------------------------------------------
+-- |
+-- Module      :  XUtil
+-- Copyright   :  (C) 2011, 2012, 2013, 2014, 2015, 2017, 2018 Jose Antonio Ortega Ruiz
+--                (C) 2007 Andrea Rossato
+-- License     :  BSD3
+--
+-- Maintainer  :  jao@gnu.org
+-- Stability   :  unstable
+-- Portability :  unportable
+--
+-----------------------------------------------------------------------------
+
+module Xmobar.X11.XUtil
+    ( XFont(..)
+    , initFont
+    , initCoreFont
+    , initUtf8Font
+    , textExtents
+    , textWidth
+    ) where
+
+import Control.Exception (SomeException, handle)
+import Data.List
+import Foreign
+import Graphics.X11.Xlib hiding (textExtents, textWidth)
+import qualified Graphics.X11.Xlib as Xlib (textExtents, textWidth)
+import Graphics.X11.Xlib.Extras
+import System.Mem.Weak ( addFinalizer )
+
+#if defined XFT
+import Xmobar.X11.MinXft
+import Graphics.X11.Xrender
+#else
+import System.IO(hPutStrLn, stderr)
+#endif
+
+data XFont = Core FontStruct
+           | Utf8 FontSet
+#ifdef XFT
+           | Xft  [AXftFont]
+#endif
+
+-- | When initFont gets a font name that starts with 'xft:' it switchs
+-- to the Xft backend Example: 'xft:Sans-10'
+initFont :: Display -> String -> IO XFont
+initFont d s =
+       let xftPrefix = "xft:" in
+       if  xftPrefix `isPrefixOf` s then
+#ifdef XFT
+           fmap Xft $ initXftFont d s
+#else
+           do
+               hPutStrLn stderr $ "Warning: Xmobar must be built with "
+                   ++ "the with_xft flag to support font '" ++ s
+                   ++ ".' Falling back on default."
+               initFont d miscFixedFont
+#endif
+       else
+           fmap Utf8 $ initUtf8Font d s
+
+miscFixedFont :: String
+miscFixedFont = "-misc-fixed-*-*-*-*-*-*-*-*-*-*-*-*"
+
+-- | Given a fontname returns the font structure. If the font name is
+--  not valid the default font will be loaded and returned.
+initCoreFont :: Display -> String -> IO FontStruct
+initCoreFont d s = do
+  f <- handle fallBack getIt
+  addFinalizer f (freeFont d f)
+  return f
+      where getIt = loadQueryFont d s
+            fallBack :: SomeException -> IO FontStruct
+            fallBack = const $ loadQueryFont d miscFixedFont
+
+-- | Given a fontname returns the font structure. If the font name is
+--  not valid the default font will be loaded and returned.
+initUtf8Font :: Display -> String -> IO FontSet
+initUtf8Font d s = do
+  (_,_,f) <- handle fallBack getIt
+  addFinalizer f (freeFontSet d f)
+  return f
+      where getIt = createFontSet d s
+            fallBack :: SomeException -> IO ([String], String, FontSet)
+            fallBack = const $ createFontSet d miscFixedFont
+
+#ifdef XFT
+initXftFont :: Display -> String -> IO [AXftFont]
+initXftFont d s = do
+  let fontNames = wordsBy (== ',') (drop 4 s)
+  mapM openFont fontNames
+  where
+    openFont fontName = do
+        f <- openAXftFont d (defaultScreenOfDisplay d) fontName
+        addFinalizer f (closeAXftFont d f)
+        return f
+    wordsBy p str = case dropWhile p str of
+                        ""   -> []
+                        str' -> w : wordsBy p str''
+                                where
+                                    (w, str'') = break p str'
+#endif
+
+textWidth :: Display -> XFont -> String -> IO Int
+textWidth _   (Utf8 fs) s = return $ fromIntegral $ wcTextEscapement fs s
+textWidth _   (Core fs) s = return $ fromIntegral $ Xlib.textWidth fs s
+#ifdef XFT
+textWidth dpy (Xft xftdraw) s = do
+    gi <- xftTxtExtents' dpy xftdraw s
+    return $ xglyphinfo_xOff gi
+#endif
+
+textExtents :: XFont -> String -> IO (Int32,Int32)
+textExtents (Core fs) s = do
+  let (_,a,d,_) = Xlib.textExtents fs s
+  return (a,d)
+textExtents (Utf8 fs) s = do
+  let (_,rl)  = wcTextExtents fs s
+      ascent  = fromIntegral $ - (rect_y rl)
+      descent = fromIntegral $ rect_height rl + fromIntegral (rect_y rl)
+  return (ascent, descent)
+#ifdef XFT
+textExtents (Xft xftfonts) _ = do
+  ascent  <- fromIntegral `fmap` xft_ascent'  xftfonts
+  descent <- fromIntegral `fmap` xft_descent' xftfonts
+  return (ascent, descent)
+#endif