first shot at allowing click to focus windows

Main.hs

@@ -120,6 +120,14 @@ grabKeys dpy rootw = do
 -- Window manager clients normally should ignore this window if the
 -- override_redirect member is True.
 -- 
+
+safeFocus :: Window -> X ()
+safeFocus w = do ws <- gets workspace
+                 if W.member w ws
+                    then setFocus w
+                    else do b <- isRoot w
+                            when b setTopFocus
+
 handle :: Event -> X ()
 
 -- run window manager command
@@ -148,14 +156,15 @@ handle e@(MappingNotifyEvent {window = w}) = do
     io $ refreshKeyboardMapping m
     when (request e == mappingKeyboard) $ withDisplay $ io . flip grabKeys w
 
+-- click on an unfocussed window
+handle (ButtonEvent {window = w, event_type = t})
+    | t == buttonPress
+    = safeFocus w
+
 -- entered a normal window
 handle e@(CrossingEvent {window = w, event_type = t})
     | t == enterNotify  && mode e == notifyNormal && detail e /= notifyInferior
-    = do ws <- gets workspace
-         if W.member w ws
-            then setFocus w
-            else do b <- isRoot w
-                    when b setTopFocus
+    = safeFocus w
 
 -- left a window, check if we need to focus root
 handle e@(CrossingEvent {event_type = t})

Operations.hs

@@ -31,8 +31,6 @@ refresh = do
     d      <- gets display
     fls    <- gets layoutDescs
     dfltfl <- gets defaultLayoutDesc
-    --    l      <- gets layout
-    --    ratio  <- gets leftWidth
     let move w a b c e = io $ moveResizeWindow d w a b c e
     flip mapM_ (M.assocs ws2sc) $ \(n, scn) -> do
         let sc = xinesc !! scn
@@ -43,6 +41,9 @@ refresh = do
             fl = M.findWithDefault dfltfl n fls
             l  = layoutType fl
             ratio = tileFraction fl
+        mapM_ (setButtonGrab True) (W.index n ws)
+        when (n == W.current ws) $
+            maybe (return ()) (setButtonGrab False) (W.peekStack n ws)
         case l of
             Full -> whenJust (W.peekStack n ws) $ \w -> do
                                                             move w sx sy sw sh
@@ -96,6 +97,18 @@ hide w = withDisplay $ \d -> do
 -- ---------------------------------------------------------------------
 -- Window operations
 
+-- | setButtonGrab. Tell whether or not to intercept clicks on a given window
+buttonsToGrab :: [ButtonMask]
+buttonsToGrab = [button1, button2, button3]
+
+setButtonGrab :: Bool -> Window -> X ()
+setButtonGrab True  w = withDisplay $ \d -> io $ flip mapM_ buttonsToGrab (\b ->
+                            grabButton d b anyModifier w False
+                                       (buttonPressMask .|. buttonReleaseMask)
+                                       grabModeAsync grabModeSync none none)
+setButtonGrab False w = withDisplay $ \d -> io $ flip mapM_ buttonsToGrab (\b ->
+                            ungrabButton d b anyModifier w)
+
 -- | manage. Add a new window to be managed in the current workspace. Bring it into focus.
 -- If the window is already under management, it is just raised.
 --
@@ -219,5 +232,3 @@ restart :: IO ()
 restart = do prog <- getProgName
              args <- getArgs
              executeFile prog True args Nothing
-
-

TODO

@@ -25,8 +25,8 @@
     - change focus in the StackSet structure on EnterNotify
     - let mod+enter demote a master window
     - borders (low priority, maybe wait until 0.2)
-    - get this to play nicely with Xinerama (at least under TwinView, things
-      are very strange)
-    - let click events/scrollwheel events change the focus
+    - let focus-follows-mouse also change the active workspace (not just the
+      active window); note that this currently also makes click-to-focus appear
+      slightly buggy, since sometimes, the wrong window is exempted from setButtonGrab
 
 * Tile vertically/ resize height.

XMonad.hs

@@ -46,10 +46,6 @@ data XState = XState
     , defaultLayoutDesc :: {-# UNPACK #-} !LayoutDesc
     , layoutDescs   :: {-# UNPACK #-} !(M.Map Int LayoutDesc)
     -- ^ mapping of workspaces to descriptions of their layouts
-
-    --    , layout        :: {-# UNPACK #-} !Layout
-    -- how much of the screen the main window should take
-    -- , leftWidth     :: {-# UNPACK #-} !Rational
     }
 
 type WorkSpace = StackSet Window