Operations.screenWorkspace: return Nothing when the screen does not exist

darcs-hash:20070707223842-a5988-7cd70e25326d577a30279c976ae64bce3f70f2df

2 files changed, 4 insertions, 4 deletions

diff --git a/Config.hs b/Config.hs
index 655d654..579a598 100644
--- a/Config.hs
+++ b/Config.hs
@@ -163,7 +163,7 @@ keys = M.fromList $
     -- mod-{w,e,r} @@ Switch to physical/Xinerama screens 1, 2, or 3
     -- mod-shift-{w,e,r} @@ Move client to screen 1, 2, or 3
     ++
-    [((m .|. modMask, key), screenWorkspace sc >>= f)
+    [((m .|. modMask, key), screenWorkspace sc >>= flip whenJust f)
         | (key, sc) <- zip [xK_w, xK_e, xK_r] [0..]
         , (f, m) <- [(view, 0), (shift, shiftMask)]]
 
diff --git a/Operations.hs b/Operations.hs
index 0a8bd31..68524f1 100644
--- a/Operations.hs
+++ b/Operations.hs
@@ -439,9 +439,9 @@ splitVerticallyBy f = (mirrorRect *** mirrorRect) . splitHorizontallyBy f . mirr
 ------------------------------------------------------------------------
 -- Utilities
 
--- | Return workspace visible on screen 'sc', or 0.
-screenWorkspace :: ScreenId -> X WorkspaceId
-screenWorkspace sc = withWindowSet $ return . fromMaybe 0 . W.lookupWorkspace sc
+-- | Return workspace visible on screen 'sc', or Nothing.
+screenWorkspace :: ScreenId -> X (Maybe WorkspaceId)
+screenWorkspace sc = withWindowSet $ return . W.lookupWorkspace sc
 
 -- | Apply an X operation to the currently focused window, if there is one.
 withFocused :: (Window -> X ()) -> X ()