xmonad-contrib/XMonad/Layout/DraggingVisualizer.hs
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Related: https://github.com/xmonad/xmonad-contrib/issues/537
2021-06-06 18:59:05 +02:00

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Haskell

{-# LANGUAGE DeriveDataTypeable, TypeSynonymInstances, MultiParamTypeClasses, FlexibleContexts #-}
----------------------------------------------------------------------------
-- |
-- Module : XMonad.Layout.DraggingVisualizer
-- Copyright : (c) Jan Vornberger 2009
-- License : BSD3-style (see LICENSE)
--
-- Maintainer : jan.vornberger@informatik.uni-oldenburg.de
-- Stability : unstable
-- Portability : not portable
--
-- A helper module to visualize the process of dragging a window by
-- making it follow the mouse cursor. See "XMonad.Layout.WindowSwitcherDecoration"
-- for a module that makes use of this.
--
-----------------------------------------------------------------------------
module XMonad.Layout.DraggingVisualizer
( draggingVisualizer,
DraggingVisualizerMsg (..),
DraggingVisualizer,
) where
import XMonad
import XMonad.Layout.LayoutModifier
newtype DraggingVisualizer a = DraggingVisualizer (Maybe (Window, Rectangle)) deriving ( Read, Show )
draggingVisualizer :: LayoutClass l Window => l Window -> ModifiedLayout DraggingVisualizer l Window
draggingVisualizer = ModifiedLayout $ DraggingVisualizer Nothing
data DraggingVisualizerMsg = DraggingWindow Window Rectangle
| DraggingStopped
deriving ( Typeable, Eq )
instance Message DraggingVisualizerMsg
instance LayoutModifier DraggingVisualizer Window where
modifierDescription (DraggingVisualizer _) = "DraggingVisualizer"
pureModifier (DraggingVisualizer (Just dragged@(draggedWin, _))) _ _ wrs =
if draggedWin `elem` map fst wrs
then (dragged : rest, Nothing)
else (wrs, Just $ DraggingVisualizer Nothing)
where
rest = filter (\(w, _) -> w /= draggedWin) wrs
pureModifier _ _ _ wrs = (wrs, Nothing)
pureMess (DraggingVisualizer _) m = case fromMessage m of
Just (DraggingWindow w rect) -> Just $ DraggingVisualizer $ Just (w, rect)
Just DraggingStopped -> Just $ DraggingVisualizer Nothing
_ -> Nothing