placement patch to XMonad.Layout.LayoutHints

Ignore-this: 87a5efa9c841d378a808b1a4309f18

darcs-hash:20090126195950-5ccef-e8066b51c417eb5e4cd5f2821929c7f909864243.gz

1 files changed, 35 insertions, 6 deletions

diff --git a/XMonad/Layout/LayoutHints.hs b/XMonad/Layout/LayoutHints.hs
index d263f3c..953f3aa 100644
--- a/XMonad/Layout/LayoutHints.hs
+++ b/XMonad/Layout/LayoutHints.hs
@@ -17,41 +17,70 @@ module XMonad.Layout.LayoutHints
     ( -- * usage
       -- $usage
       layoutHints
+    , layoutHintsWithPlacement
     , LayoutHints
+    , placeRectangle
     ) where
 
 import XMonad hiding ( trace )
 import XMonad.Layout.LayoutModifier
 import XMonad.Layout.Decoration ( isInStack )
 
+import Control.Applicative ( (<$>) )
+import Control.Arrow ( second )
+
 -- $usage
 -- You can use this module with the following in your @~\/.xmonad\/xmonad.hs@:
 --
 -- > import XMonad.Layout.LayoutHints
 --
--- Then edit your @layoutHook@ by adding the LayoutHints layout modifier
+-- Then edit your @layoutHook@ by adding the 'layoutHints' layout modifier
 -- to some layout:
 --
 -- > myLayouts = layoutHints (Tall 1 (3/100) (1/2))  ||| Full ||| etc..
 -- > main = xmonad defaultConfig { layoutHook = myLayouts }
 --
+-- Or, to center the adapted window in its available area:
+--
+-- > myLayouts = layoutHintsWithPlacement (0.5, 0.5) (Tall 1 (3/100) (1/2))  
+-- >                   ||| Full ||| etc..
+--
 -- For more detailed instructions on editing the layoutHook see:
 --
 -- "XMonad.Doc.Extending#Editing_the_layout_hook"
 
 layoutHints :: (LayoutClass l a) => l a -> ModifiedLayout LayoutHints l a
-layoutHints = ModifiedLayout LayoutHints
+layoutHints = ModifiedLayout (LayoutHints (0, 0))
 
-data LayoutHints a = LayoutHints deriving (Read, Show)
+-- | @layoutHintsWithPlacement (rx, ry) layout@ will adapt the sizes of a layout's
+-- windows according to their size hints, and position them inside their
+-- originally assigned area according to the @rx@ and @ry@ parameters.
+-- (0, 0) places the window at the top left, (1, 0) at the top right, (0.5, 0.5)
+-- at the center, etc.
+layoutHintsWithPlacement :: (LayoutClass l a) => (Double, Double) 
+                         -> l a -> ModifiedLayout LayoutHints l a
+layoutHintsWithPlacement rs = ModifiedLayout (LayoutHints rs)
+
+data LayoutHints a = LayoutHints (Double, Double) 
+                     deriving (Read, Show)
 
 instance LayoutModifier LayoutHints Window where
     modifierDescription _ = "Hinted"
     redoLayout _ _ Nothing  xs = return (xs, Nothing)
-    redoLayout _ _ (Just s) xs = do
-                            xs' <- mapM applyHint xs
-                            return (xs', Nothing)
+    redoLayout (LayoutHints al) _ (Just s) xs 
+        = do xs' <- mapM (\x@(_, r) -> second (placeRectangle al r) <$> applyHint x) xs
+             return (xs', Nothing)
      where
         applyHint (w,r@(Rectangle a b c d)) = do
             adj <- mkAdjust w
             let (c',d') = adj (c,d)
             return (w, if isInStack s w then Rectangle a b c' d' else r)
+
+-- | @placeRectangle (rx, ry) r0 r@ will return a new rectangle with the same dimensions
+-- as @r@, but positioned inside of @r0@ as specified by the (rx, ry) parameters (see 
+-- 'layoutHintsWithPlacement').
+placeRectangle :: RealFrac r => (r, r) -> Rectangle -> Rectangle -> Rectangle
+placeRectangle (rx, ry) (Rectangle x0 y0 w h) (Rectangle _ _ dx dy)
+    = Rectangle (align x0 dx w rx) (align y0 dy h ry) dx dy
+    where align :: RealFrac r => Position -> Dimension -> Dimension -> r -> Position
+          align z0 dz d r = z0 + truncate (fromIntegral (d - dz) * r)
\ No newline at end of file