From f1a0796da3fd68733bc44923c6851c7839cfeabc Mon Sep 17 00:00:00 2001
From: Spencer Janssen <sjanssen@cse.unl.edu>
Date: Tue, 20 Mar 2007 05:11:24 +0000
Subject: [PATCH] Decouple the concepts of focus and window order. First step
to tiling!
---
Main.hs | 2 +-
StackSet.hs | 33 ++++++++++++++++++++++++---------
2 files changed, 25 insertions(+), 10 deletions(-)
diff --git a/Main.hs b/Main.hs
index a877728..a63c8ef 100644
--- a/Main.hs
+++ b/Main.hs
@@ -225,7 +225,7 @@ refresh = do
ws2sc <- gets wsOnScreen
xinesc <- gets xineScreens
forM_ (M.assocs ws2sc) $ \(n, scn) ->
- whenJust (listToMaybe $ W.index n ws) $ \w -> withDisplay $ \d -> do
+ whenJust (W.peekStack n ws) $ \w -> withDisplay $ \d -> do
let sc = xinesc !! scn
io $ do moveResizeWindow d w (fromIntegral $ xsi_x_org sc)
(fromIntegral $ xsi_y_org sc)
diff --git a/StackSet.hs b/StackSet.hs
index 1453c97..3604f3b 100644
--- a/StackSet.hs
+++ b/StackSet.hs
@@ -37,6 +37,7 @@ data StackSet a =
StackSet
{ current:: {-# UNPACK #-} !Int -- ^ the currently visible stack
, stacks :: {-# UNPACK #-} !(M.Map Int [a]) -- ^ the separate stacks
+ , focus :: {-# UNPACK #-} !(M.Map Int a) -- ^ the window focused in each stack
, cache :: {-# UNPACK #-} !(M.Map a Int) -- ^ a cache of windows back to their stacks
} deriving Eq
@@ -55,6 +56,7 @@ instance Show a => Show (StackSet a) where
empty :: Int -> StackSet a
empty n = StackSet { current = 0
, stacks = M.fromList (zip [0..n-1] (repeat []))
+ , focus = M.empty
, cache = M.empty }
-- | /O(log w)/. True if x is somewhere in the StackSet
@@ -97,7 +99,12 @@ push k w = insert k (current w) w
-- | /O(log s)/. Extract the element on the top of the current stack. If no such
-- element exists, Nothing is returned.
peek :: StackSet a -> Maybe a
-peek w = listToMaybe $ index (current w) w
+peek w = peekStack (current w) w
+
+-- | /O(log s)/. Extract the element on the top of the given stack. If no such
+-- element exists, Nothing is returned.
+peekStack :: Int -> StackSet a -> Maybe a
+peekStack n w = M.lookup n (focus w)
-- | /O(log s)/. Index. Extract the stack at index 'n'.
-- If the index is invalid, an exception is thrown.
@@ -118,12 +125,15 @@ view n w | n >= 0 && n < M.size (stacks w) = w { current = n }
--
-- where xs = [5..8] ++ [1..4]
--
-rotate :: Ordering -> StackSet a -> StackSet a
-rotate o w = w { stacks = M.adjust rot (current w) (stacks w) }
- where rot s = take l . drop offset . cycle $ s
- where n = fromEnum o - 1
- l = length s
- offset = if n < 0 then l + n else n
+rotate :: Eq a => Ordering -> StackSet a -> StackSet a
+rotate o w = maybe w id $ do
+ f <- M.lookup (current w) (focus w)
+ s <- M.lookup (current w) (stacks w)
+ ea <- case o of
+ EQ -> Nothing
+ GT -> elemAfter f s
+ LT -> elemAfter f (reverse s)
+ return (w { focus = M.insert (current w) ea (focus w) })
-- | /O(log n)/. shift. move the client on top of the current stack to
-- the top of stack 'n'. If the stack to move to is not valid, and
@@ -139,7 +149,8 @@ shift n w = maybe w (\k -> insert k n (delete k w)) (peek w)
--
insert :: Ord a => a -> Int -> StackSet a -> StackSet a
insert k n old = new { cache = M.insert k n (cache new)
- , stacks = M.adjust (k:) n (stacks new) }
+ , stacks = M.adjust (k:) n (stacks new)
+ , focus = M.insert n k (focus new) }
where new = delete k old
-- | /O(log n)/. Delete an element entirely from from the StackSet.
@@ -148,4 +159,8 @@ insert k n old = new { cache = M.insert k n (cache new)
delete :: Ord a => a -> StackSet a -> StackSet a
delete k w = maybe w tweak (M.lookup k (cache w))
where tweak i = w { cache = M.delete k (cache w)
- , stacks = M.adjust (L.delete k) i (stacks w) }
+ , stacks = M.adjust (L.delete k) i (stacks w)
+ , focus = M.update (\k' -> if k == k' then elemAfter k (stacks w M.! i) else Just k') i (focus w) }
+
+elemAfter :: Eq a => a -> [a] -> Maybe a
+elemAfter w ws = listToMaybe . filter (/= w) . dropWhile (/= w) $ ws ++ ws