Nicer downscaling of taskbar icons

lib/Phi/Widgets/Taskbar.hs

@@ -58,25 +58,43 @@ desaturateIconStyle v icon = do
   w <- imageSurfaceGetWidth icon
   h <- imageSurfaceGetHeight icon
   
-  renderWithSimilarSurface ContentColorAlpha w h $ \surface1 -> do
+  renderWithSimilarSurface ContentColorAlpha w h $ \surface -> do
-    renderWithSimilarSurface ContentColor w h $ \surface2 -> do
+    renderWith surface $ do
-      renderWith surface1 $ do
+      setOperator OperatorAdd
-        renderWith surface2 $ do
+      withPatternForSurface icon setSource
-          withPatternForSurface icon setSource
+      paint
-          paint
     
-          setOperator OperatorHslSaturation
+      setSourceRGB 0 0 0
-          setSourceRGBA 0 0 0 (1-v)
+      paint
-          paint
       
-        withPatternForSurface surface2 setSource
+      setOperator OperatorHslSaturation
-        paint
+      setSourceRGBA 0 0 0 (1-v)
+      paint
         
-        setOperator OperatorDestIn
+      setOperator OperatorDestIn
-        withPatternForSurface icon setSource
+      withPatternForSurface icon setSource
-        paint
+      paint
+    
+    withPatternForSurface surface setSource
+
+downscaled :: Double -> Surface -> Render ()
+downscaled s surface = do
+    case True of
+      _ | s < 0.5 -> do
+        w <- imageSurfaceGetWidth surface
+        h <- imageSurfaceGetHeight surface
+        
+        renderWithSimilarSurface ContentColorAlpha w h $ \surface' -> do
+          renderWith surface' $ do
+            scale 0.5 0.5
+            downscaled (2*s) surface
+            paint
+          withPatternForSurface surface' setSource
+        
+        | otherwise -> do
+        scale s s
+        withPatternForSurface surface setSource
       
-      withPatternForSurface surface1 setSource
 
 data TaskStyle = TaskStyle { taskFont      :: !String
                            , taskColor     :: !Color
@@ -218,12 +236,13 @@ instance WidgetClass Taskbar where
                 imageH <- imageSurfaceGetHeight icon
                 
                 let scalef = (fromIntegral h')/(fromIntegral $ max imageW imageH)
-                scale scalef scalef
                 
-                when (imageH < imageW) $
+                renderWithSimilarSurface ContentColorAlpha imageW imageH $ \surface -> do
-                  translate 0 $ (fromIntegral (imageW-imageH))/2
+                  renderWith surface $ do
+                    taskIconStyle style icon
+                    paint
+                  downscaled scalef surface
                 
-                taskIconStyle style icon
                 paint
                 restore