Make render function return cachable surface slices

1 files changed, 15 insertions, 11 deletions

diff --git a/lib/Phi/Widgets/AlphaBox.hs b/lib/Phi/Widgets/AlphaBox.hs
index eacda5a..cd540e3 100644
--- a/lib/Phi/Widgets/AlphaBox.hs
+++ b/lib/Phi/Widgets/AlphaBox.hs
@@ -12,11 +12,11 @@ import Control.Monad
 import Graphics.Rendering.Cairo
 
 
-data AlphaBox w d = (Widget w d) => AlphaBox !Double !w
-deriving instance Show (AlphaBox w d)
-deriving instance Eq (AlphaBox w d)
+data AlphaBox w s c = (Widget w s c) => AlphaBox !Double !w
+deriving instance Show (AlphaBox w s c)
+deriving instance Eq (AlphaBox w s c)
 
-instance Eq d => Widget (AlphaBox w d) d where
+instance Eq s => Widget (AlphaBox w s c) s () where
   initWidget (AlphaBox _ w) = initWidget w
   
   minSize (AlphaBox _ w) = minSize w
@@ -25,21 +25,25 @@ instance Eq d => Widget (AlphaBox w d) d where
   
   layout (AlphaBox _ w) = layout w
 
-  render (AlphaBox alpha w) d x y width height screen = do
-    renderWithSimilarSurface ContentColorAlpha width height $ \surface -> do
-      renderWith surface $ do
-        render w d x y width height screen
+  render (AlphaBox alpha w) s x y width height screen = do
+    surfaces <- render w s x y width height screen
+    let surfacesWidths = zipWith (\(updated, SurfaceSlice x surf) x' -> (updated, x, x'-x, surf)) surfaces (map (\(_, SurfaceSlice x _) -> x) (tail surfaces) ++ [width])
+    forM surfacesWidths $ \(updated, x, surfWidth, surf) -> do
+      surf' <- createImageSurface FormatARGB32  surfWidth height
+      renderWith surf' $ do
+        setOperator OperatorSource
+        withPatternForSurface surf setSource
+        paint
         
         setOperator OperatorDestIn
         setSourceRGBA 0 0 0 alpha
         paint
       
-      withPatternForSurface surface setSource
-      paint
+      return (updated, SurfaceSlice x surf')
   
   handleMessage (AlphaBox _ w) = handleMessage w
 
 
-alphaBox :: (Widget w d) => Double -> w -> AlphaBox w d
+alphaBox :: (Widget w s c) => Double -> w -> AlphaBox w s c
 alphaBox = AlphaBox