On Sat, Jun 09, 2007 at 12:27:00PM -0700, David Roundy wrote:
> Hi all,
> 
> Here's some infrastructure to allow layouts to define window decorations
> such as tabs or title bars.  I'm mostly sending it in to get comments.
> I soon hope to have a crude tabbed layout using this.

Cool!  In the spirit of comments, I think I see a simpler and more
general way to accomplish this.  Expect a counterpatch shortly!

Why restrict the core to *decorations*?  This can be generalized:

1. Have a transientRestore :: [X ()] hook in the state, which is used by
   the decoration manager (a XMonadContrib module) to remove decorations.

2. Have a eventHandlers :: M.Map WindowId (Event -> X ()) which
   specifies what to do when other windows get events.  This gives
   Xmonad the toolkit-like facilities to implement drawing, clicking,
   etc decorations.

With this your decoration manager could be implemented in XMonadContrib.

> Sat Jun  9 12:23:49 PDT 2007  David Roundy 
>   * add decorations infrastructure
> 

Content-Description: A darcs patch for your repository!
> 
> New patches:
> 
> [add decorations infrastructure
> David Roundy **20070609192349] 
> <
> > {
> hunk ./Main.hs 66
>          st = XState
>              { windowset     = winset
>              , layouts       = M.fromList [(w, safeLayouts) | w <- [0 .. W workspaces - 1]]
> +            , decorations   = []
>              , statusGaps    = take (length xinesc) $ defaultGaps ++ repeat (0,0,0,0)
>              , xineScreens   = xinesc
>              , mapped        = S.empty
> hunk ./Main.hs 186
>      | t == buttonPress = do
>      isr <- isRoot w
>      if isr then whenJust (M.lookup (cleanMask (ev_state e), b) mouseBindings) ($ ev_subwindow e)
> -           else focus w
> +           else do withDecoration w clickDecoration
> +                   focus w
>      -- If it's the root window, then it's something we
>      -- grabbed in grabButtons. Otherwise, it's click-to-focus.
>  
> hunk ./Main.hs 228
>  -- the root may have configured
>  handle (ConfigureEvent {ev_window = w}) = whenX (isRoot w) rescreen
>  
> +handle (AnyEvent {ev_event_type = t, ev_window = w})
> +    | t == expose = withDecoration w drawDecoration
> +
>  handle _ = return () -- trace (eventName e) -- ignoring
> hunk ./Operations.hs 127
>  -- | windows. Modify the current window list with a pure function, and refresh
>  windows :: (WindowSet -> WindowSet) -> X ()
>  windows f = do
> +    destroyDecorations
>      XState { windowset = old, layouts = fls, xineScreens = xinesc, statusGaps = gaps } <- get
>      let ws = f old
>      modify (\s -> s { windowset = ws })
> hunk ./Operations.hs 551
>  applyMaxSizeHint (mw,mh) x@(w,h) =
>      if mw > 0 && mh > 0 then (min w mw,min h mh) else x
>  
> +destroyDecorations :: X ()
> +destroyDecorations = do decs <- gets decorations
> +                        modify $ \x -> x { decorations = [] }
> +                        withDisplay $ \d -> forM_ decs (io . destroyWindow d . decorationWindow)
> +
> +addDecoration :: Decoration -> X ()
> +addDecoration dec = do modify $ \x -> x { decorations = dec : decorations x }
> +                       withDisplay $ \d -> io $ mapWindow d (decorationWindow dec)
> +
> +withDecoration :: Window -> (Decoration -> X ()) -> X ()
> +withDecoration w f = do decs <- filter ((==w) . decorationWindow) `fmap` gets decorations
> +                        case decs of
> +                          (x:_) -> f x
> +                          _ -> return ()
> +
> hunk ./XMonad.hs 20
>  
>  module XMonad (
>      X, WindowSet, WorkspaceId(..), ScreenId(..), XState(..), XConf(..), Layout(..),
> +    Decoration, decorationWindow, drawDecoration, clickDecoration, newDecoration,
>      Typeable, Message, SomeMessage(..), fromMessage, atom_WM_PROTOCOLS, atom_WM_DELETE_WINDOW,
>      runX, io, withDisplay, withWindowSet, isRoot, spawn, restart, trace, whenJust, whenX,
>      atom_WM_STATE
> hunk ./XMonad.hs 48
>      , statusGaps   :: ![(Int,Int,Int,Int)] -- ^ width of status bar on each screen
>      , mapped       :: !(S.Set Window)      -- ^ the Set of mapped windows
>      , waitingUnmap :: !(M.Map Window Int)  -- ^ the number of expected UnmapEvents
> +    , decorations  :: ![Decoration]        -- ^ currently visible decorations
>      , layouts      :: !(M.Map WorkspaceId (Layout, [Layout])) }
>                         -- ^ mapping of workspaces to descriptions of their layouts
>  data XConf = XConf
> hunk ./XMonad.hs 107
>  atom_WM_DELETE_WINDOW   = getAtom "WM_DELETE_WINDOW"
>  atom_WM_STATE           = getAtom "WM_STATE"
>  
> +------------------------------------------------------------------------
> +-- Decorations
> +
> +data Decoration = Decoration { decorationWindow :: Window
> +                             , drawDecoration :: X ()
> +                             , clickDecoration :: X () }
> +
> +newDecoration :: Rectangle -> Int -> Pixel -> Pixel -> X Decoration
> +newDecoration (Rectangle x y w h) th fg bg =
> +    withDisplay $ \d -> do rt <- asks theRoot
> +                           win <- io $ createSimpleWindow d rt x y w h (fromIntegral th) fg bg
> +                           return $ Decoration win (return ()) (return ())
> +
>  ------------------------------------------------------------------------
>  -- Layout handling