Add some comments and type signatures.

[matthijs/projects/fpprac.git] / FPPrac.hs

diff --git a/FPPrac.hs b/FPPrac.hs
index 5da734e98aebb4e9917f06b3f444a4d2f1b48afc..14e8c4f872036b122449cf12242e3338936520c5 100644 (file)
--- a/FPPrac.hs
+++ b/FPPrac.hs
@@ -236,6 +236,8 @@ transKey _ _ = return ()
 
 -}
 
+-- | Handlers for various requests.
+miscHandler, winHandler, gfxHandler :: IState -> Request -> Maybe (IO ())
 {-
 miscHandler s@IS {..} (FRead  fn     ) = Just $ readFile fn >>= post s . FileContents fn
 miscHandler   IS {..} (FWrite fn cnts) = Just $ writeFile fn cnts
@@ -278,11 +280,16 @@ gfxHandler IS {..} (GfxDisc      col rt)    = Just $ ellipse buffer rt [penColor
 gfxHandler IS {..} (GfxFont      st  sz)    = Just $ buffer `set` [ fontSize := sz, fontFace := st ]
 gfxHandler IS {..} (GfxPicture   fd  pt)    = Just $ bitmapCreateFromFile fd >>= \bm -> drawBitmap buffer bm pt False [] >> bitmapGetSize bm >>= dirtyRect' sPanel pt
 -}
+-- | Helper function for gfxHanlder
+gfxHandler' :: Request -> Maybe (Cairo.Render ())
 gfxHandler' (GfxText col (Point x y) st) = Just $ do
+       -- Set the source color, move to the requested position and draw the
+       -- text
        setSourceColor col
        Cairo.moveTo (fromIntegral x) (fromIntegral y)
        Cairo.showText st 
 gfxHandler' GfxClear = Just $ do
+       -- Set the source to white and paint the entire surface with it
        Cairo.setSourceRGB 1 1 1
        Cairo.paint
 gfxHandler' _ = Nothing