[Add HSX.Layout
Niklas Broberg <nibro@cs.chalmers.se>**20080326215515] {
addfile ./HSX/Layout.hs
hunk ./HSX/Layout.hs 1
+{-# OPTIONS_GHC -fglasgow-exts #-}
+{-# OPTIONS_GHC -fallow-undecidable-instances #-}
+{-# OPTIONS_GHC -fallow-overlapping-instances #-}
+module HSX.Layout (
+        Layout(..), IsLayout(..),
+        above, beside, (^^), (<>)
+    )where
+
+import Prelude hiding ((^^))
+
+import HSX.XMLGenerator
+
+data Layoutm
+  = Above (Layout m) (Layout m)
+  | Beside (Layout m) (Layoutm)
+  | Item (XMLGenT m [Child m])
+
+class IsLayout m a where
+ toLayout :: a -> Layout m
+
+
+instance IsLayout m (Layout m) where
+ toLayout = id
+
+instance (EmbedAsChild m c) => IsLayout m c where
+ toLayout = Item . asChild
+
+(^^),(<>),above,beside :: (IsLayout m a, IsLayout m b) =>a -> b -> Layout m
+a ^^ b = Above  (toLayout a) (toLayout b)
+a <> b = Beside (toLayout a) (toLayout b)
+above = (^^)
+beside = (<>)
+
+
+instance (XMLGenerator m, 
+          EmbedAsChild m (XMLGenT m (XML m)), 
+          EmbedAsChild m (XMLGenT m [XML m]),
+          EmbedAsAttr  m (Attr String String))
+          => EmbedAsChild m (Layout m) where
+ asChild a@(Above _ _) = asChild (
+   <table border="0"><% 
+       mapM mkRow $ foldAbove a :: XMLGenT m [XML m]
+   %></table> :: XMLGenT m (XML m))
+ asChild b@(Beside _ _) = asChild (
+   <table border="0"><%
+     <tr><% 
+       mapM mkCell $ foldBeside b :: XMLGenT m [XML m] 
+     %></tr>  :: XMLGenT m (XML m)
+   %></table> :: XMLGenT m (XML m))
+ asChild (Item xml) = xml
+
+foldAbove :: Layout m -> [Layout m]
+foldAbove (Above a b) = foldAbove a ++ foldAbove b
+foldAbove l = [l]
+
+foldBeside :: Layout m -> [Layout m]
+foldBeside (Beside a b) = foldBeside a ++ foldBeside b
+foldBeside l = [l]
+
+mkRow :: forall m c . (XMLGenerator m, 
+                       EmbedAsChild m c, 
+                       EmbedAsChild m (XMLGenT m (XML m))) 
+       => c -> XMLGenT m (XML m)
+mkRow xml = <tr><% (mkCell xml :: XMLGenT m (XML m)) %></tr> 
+
+mkCell :: (XMLGenerator m, EmbedAsChild m c) => c -> XMLGenT m (XML m)
+mkCell xml = <td><% xml %></td>
hunk ./hsx.cabal 36
-Exposed-Modules:        HSX.XMLGenerator
+Exposed-Modules:        HSX.XMLGenerator, HSX.Layout
}