Don't use the widget definition as a part of the render cache state

lib/Phi/Widget.hs

@@ -86,7 +86,7 @@ class Eq s => Widget w s c | w -> s, w -> c where
   handleMessage _ priv _ = priv
 
 type IOCache = CacheArrow (Kleisli IO)
-type RenderCache w s = IOCache (w, s, Int, Int, Int, Int, Xlib.Rectangle) Surface
+type RenderCache s = IOCache (s, Int, Int, Int, Int, Xlib.Rectangle) Surface
 
 createIOCache :: Eq a => (a -> IO b) -> IOCache a b
 createIOCache = lift . Kleisli
@@ -98,21 +98,21 @@ runIOCache a = do
   put cache'
   return b
 
-createRenderCache :: (w -> s -> Int -> Int -> Int -> Int -> Xlib.Rectangle -> Render ())
-                     -> CacheArrow (Kleisli IO) (w, s, Int, Int, Int, Int, Xlib.Rectangle) Surface
-createRenderCache f = lift . Kleisli $ \(widget, state, x, y, w, h, screen) -> do
+createRenderCache :: (s -> Int -> Int -> Int -> Int -> Xlib.Rectangle -> Render ())
+                     -> CacheArrow (Kleisli IO) (s, Int, Int, Int, Int, Xlib.Rectangle) Surface
+createRenderCache f = lift . Kleisli $ \(state, x, y, w, h, screen) -> do
   surface <- createImageSurface FormatARGB32 w h
   renderWith surface $ do
     setOperator OperatorClear
     paint
     setOperator OperatorOver
-    f widget state x y w h screen
+    f state x y w h screen
   return surface
 
-renderCached :: (Eq w, Eq s) => w -> s -> Int -> Int -> Int -> Int -> Xlib.Rectangle -> StateT (RenderCache w s) IO [(Bool, SurfaceSlice)]
-renderCached widget state x y w h screen = do
+renderCached :: Eq s => s -> Int -> Int -> Int -> Int -> Xlib.Rectangle -> StateT (RenderCache s) IO [(Bool, SurfaceSlice)]
+renderCached state x y w h screen = do
   cache <- get
-  (surf, updated, cache') <- liftIO $ runKleisli (runCache' cache) (widget, state, x, y, w, h, screen)
+  (surf, updated, cache') <- liftIO $ runKleisli (runCache' cache) (state, x, y, w, h, screen)
   put cache'
   return [(updated, SurfaceSlice 0 surf)]
 
@@ -157,15 +157,15 @@ a <~> b = CompoundWidget a b
 
 data Separator = Separator !Int !Float deriving (Show, Eq)
 
-instance Widget Separator () (RenderCache Separator ()) where
+instance Widget Separator () (RenderCache ()) where
   initWidget _ _ _ _ = return ()
-  initCache _ = createRenderCache $ \_ _ _ _ _ _ _ -> do
+  initCache _ = createRenderCache $ \_ _ _ _ _ _ -> do
     setOperator OperatorClear
     paint
   
   minSize (Separator s _) _ _ _ = s
   weight (Separator _ w) = w
-  render = renderCached
+  render _ = renderCached
 
 
 separator :: Int -> Float -> Separator

lib/Phi/Widgets/Clock.hs

@@ -42,7 +42,7 @@ data ClockState = ClockState !ZonedTime deriving (Show, Eq)
 
 data ClockMessage = UpdateTime !ZonedTime deriving (Show, Typeable)
 
-instance Widget Clock ClockState (RenderCache Clock ClockState) where
+instance Widget Clock ClockState (RenderCache ClockState) where
   initWidget (Clock _) phi _ _ = do
     forkIO $ forever $ do
       time <- getZonedTime
@@ -54,7 +54,7 @@ instance Widget Clock ClockState (RenderCache Clock ClockState) where
     time <- getZonedTime
     return $ ClockState time
   
-  initCache _ = createRenderCache $ \(Clock config) (ClockState time) _ _ w h _ -> do
+  initCache (Clock config) = createRenderCache $ \(ClockState time) _ _ w h _ -> do
     let (r, g, b, a) = fontColor config
         str = formatTime defaultTimeLocale (clockFormat config) time
     setSourceRGBA r g b a
@@ -78,7 +78,7 @@ instance Widget Clock ClockState (RenderCache Clock ClockState) where
     
   minSize (Clock config) _ _ _ = clockSize config
   
-  render = renderCached
+  render _ = renderCached
   
   handleMessage _ priv m = case (fromMessage m) of
     Just (UpdateTime time) -> ClockState time

lib/Phi/Widgets/Systray.hs

@@ -48,14 +48,14 @@ data SystrayMessage = AddIcon !Window !Window | RemoveIcon !Window | RenderIcon
                       deriving (Show, Typeable)
 
 
-instance Widget Systray SystrayState (RenderCache Systray SystrayState) where
+instance Widget Systray SystrayState (RenderCache SystrayState) where
   initWidget (Systray) phi dispvar screens = do
     phi' <- dupPhi phi
     forkIO $ systrayRunner phi' dispvar $ snd . head $ screens
     
     return $ SystrayState phi (fst . head $ screens) 0 []
   
-  initCache _ = createRenderCache $ \Systray (SystrayState phi systrayScreen reset icons) x y w h screen -> do
+  initCache _ = createRenderCache $ \(SystrayState phi systrayScreen reset icons) x y w h screen -> do
     when (screen == systrayScreen) $ do
       forM_ (zip [0..] icons) $ \(i, SystrayIconState midParent window) -> do
         let x' = x + i*(h+2)
@@ -70,7 +70,7 @@ instance Widget Systray SystrayState (RenderCache Systray SystrayState) where
 
   weight _ = 0
   
-  render = renderCached
+  render _ = renderCached
 
   
   handleMessage _ priv@(SystrayState phi screen reset icons) m = case (fromMessage m) of