content: {-# LANGUAGE DeriveDataTypeable, MultiParamTypeClasses, TypeSynonymInstances, PatternGuards #-}
  -----------------------------------------------------------------------------
  -- |
  -- Module      :  XMonad.Layout.Magnifier
  -- Copyright   :  (c) Peter De Wachter and Andrea Rossato 2007
  -- License     :  BSD-style (see xmonad/LICENSE)
  --
  -- Maintainer  :  andrea.rossato@unibz.it
  -- Stability   :  unstable
  -- Portability :  unportable
  --
  -- Screenshot  :  <http://caladan.rave.org/magnifier.png>
  --
  -- This is a layout modifier that will make a layout increase the size
  -- of the window that has focus.
  --
  -----------------------------------------------------------------------------
  
  
  module XMonad.Layout.Magnifier
      ( -- * Usage
        -- $usage
        magnifier,
        magnifier',
        magnifierOff,
        magnifiercz,
        magnifiercz',
        maximizeVertical,
        MagnifyMsg (..),
        Magnifier,
      ) where
  
  import XMonad
  import XMonad.StackSet
  import XMonad.Layout.LayoutModifier
  import XMonad.Util.XUtils
  
  -- $usage
  -- You can use this module with the following in your @~\/.xmonad\/xmonad.hs@:
  --
  -- > import XMonad.Layout.Magnifier
  --
  -- Then edit your @layoutHook@ by adding the 'magnifier' layout modifier
  -- to some layout:
  --
  -- > myLayout = magnifier (Tall 1 (3/100) (1/2))  ||| Full ||| etc..
  -- > main = xmonad def { layoutHook = myLayout }
  --
  -- By default magnifier increases the focused window's size by 1.5.
  -- You can also use:
  --
  -- > magnifiercz 1.2
  --
  -- to use a custom level of magnification.  You can even make the focused
  -- window smaller for a pop in effect.
  --
  -- For more detailed instructions on editing the layoutHook see:
  --
  -- "XMonad.Doc.Extending#Editing_the_layout_hook"
  --
  -- Magnifier supports some commands. To use them add something like
  -- this to your key bindings:
  --
  -- >    , ((modm .|. controlMask              , xK_plus ), sendMessage MagnifyMore)
  -- >    , ((modm .|. controlMask              , xK_minus), sendMessage MagnifyLess)
  -- >    , ((modm .|. controlMask              , xK_o    ), sendMessage ToggleOff  )
  -- >    , ((modm .|. controlMask .|. shiftMask, xK_o    ), sendMessage ToggleOn   )
  -- >    , ((modm .|. controlMask              , xK_m    ), sendMessage Toggle     )
  --
  -- Note that a few other extension modules, such as
  -- "XMonad.Layout.MultiToggle" and "XMonad.Layout.ToggleLayouts", also
  -- define a message named 'Toggle'.  To avoid conflicts when using
  -- these modules together, you can import Magnifier qualified, like
  -- this:
  --
  -- > import qualified XMonad.Layout.Magnifier as Mag
  --
  -- and then prefix @Mag@ to the front of everything from this module,
  -- like @Mag.Toggle@, @Mag.magnifier@, and so on.
  --
  -- For detailed instruction on editing the key binding see
  -- "XMonad.Doc.Extending#Editing_key_bindings".
  
  -- | Increase the size of the window that has focus
  magnifier :: l a -> ModifiedLayout Magnifier l a
  magnifier = ModifiedLayout (Mag (1.5,1.5) On All)
  
  -- | Change the size of the window that has focus by a custom zoom
  magnifiercz :: Rational -> l a -> ModifiedLayout Magnifier l a
  magnifiercz cz = ModifiedLayout (Mag (fromRational cz, fromRational cz) On All)
  
  -- | Increase the size of the window that has focus, unless if it is the
  -- master window.
  magnifier' :: l a -> ModifiedLayout Magnifier l a
  magnifier' = ModifiedLayout (Mag (1.5,1.5) On NoMaster)
  
  -- | Magnifier that defaults to Off
  magnifierOff :: l a -> ModifiedLayout Magnifier l a
  magnifierOff = ModifiedLayout (Mag (1.5,1.5) Off All)
  
  -- | Increase the size of the window that has focus by a custom zoom,
  -- unless if it is the master window.
  magnifiercz' :: Rational -> l a -> ModifiedLayout Magnifier l a
  magnifiercz' cz = ModifiedLayout (Mag (fromRational cz, fromRational cz) On NoMaster)
  
  -- | A magnifier that greatly magnifies just the vertical direction
  maximizeVertical :: l a -> ModifiedLayout Magnifier l a
  maximizeVertical = ModifiedLayout (Mag (1,1000) Off All)
  
  data MagnifyMsg = MagnifyMore | MagnifyLess | ToggleOn | ToggleOff | Toggle deriving ( Typeable )
  instance Message MagnifyMsg
  
  data Magnifier a = Mag (Double,Double) Toggle MagnifyMaster deriving (Read, Show)
  
  data Toggle        = On  | Off      deriving  (Read, Show)
  data MagnifyMaster = All | NoMaster deriving  (Read, Show)
  
  instance LayoutModifier Magnifier Window where
      redoLayout  (Mag z On All     ) r (Just s) wrs = applyMagnifier z r s wrs
      redoLayout  (Mag z On NoMaster) r (Just s) wrs = unlessMaster (applyMagnifier z) r s wrs
      redoLayout  _                   _ _        wrs = return (wrs, Nothing)
  
      handleMess (Mag z On  t) m
                      | Just MagnifyMore <- fromMessage m = return . Just $ (Mag (z `addto`   0.1 ) On  t)
                      | Just MagnifyLess <- fromMessage m = return . Just $ (Mag (z `addto` (-0.1)) On  t)
                      | Just ToggleOff   <- fromMessage m = return . Just $ (Mag (z      ) Off t)
                      | Just Toggle      <- fromMessage m = return . Just $ (Mag (z      ) Off t)
                      where addto (x,y) i = (x+i,y+i)
      handleMess (Mag z Off t) m
                      | Just ToggleOn    <- fromMessage m = return . Just $ (Mag z         On  t)
                      | Just Toggle      <- fromMessage m = return . Just $ (Mag z         On  t)
      handleMess _ _ = return Nothing
  
      modifierDescription (Mag _ On  All     ) = "Magnifier"
      modifierDescription (Mag _ On  NoMaster) = "Magnifier NoMaster"
      modifierDescription (Mag _ Off _       ) = "Magnifier (off)"
  
  type NewLayout a = Rectangle -> Stack a -> [(Window, Rectangle)] -> X ([(Window, Rectangle)], Maybe (Magnifier a))
  
  unlessMaster :: NewLayout a -> NewLayout a
  unlessMaster mainmod r s wrs = if null (up s) then return (wrs, Nothing)
                                                else mainmod r s wrs
  
  applyMagnifier :: (Double,Double) -> Rectangle -> t -> [(Window, Rectangle)]
                 -> X ([(Window, Rectangle)], Maybe a)
  applyMagnifier z r _ wrs = do focused <- withWindowSet (return . peek)
                                let mag (w,wr) ws | focused == Just w = ws ++ [(w, fit r $ magnify z wr)]
                                                  | otherwise         = (w,wr) : ws
                                return (reverse $ foldr mag [] wrs, Nothing)
  
  magnify :: (Double, Double) -> Rectangle -> Rectangle
  magnify (zoomx,zoomy) (Rectangle x y w h) = Rectangle x' y' w' h'
      where x' = x - fromIntegral (w' - w) `div` 2
            y' = y - fromIntegral (h' - h) `div` 2
            w' = round $ fromIntegral w * zoomx
            h' = round $ fromIntegral h * zoomy
  
  fit :: Rectangle -> Rectangle -> Rectangle
  fit (Rectangle sx sy sw sh) (Rectangle x y w h) = Rectangle x' y' w' h'
      where x' = max sx (x - (max 0 (x + fi w - sx - fi sw)))
            y' = max sy (y - (max 0 (y + fi h - sy - fi sh)))
            w' = min sw w
            h' = min sh h
  