Merge pull request #403 from elkowar/fullscreen-fix

Add new module XMonad.Util.Hacks (formerly XMonad.Hooks.WindowedFullscreenFix)

XMonad/Doc/Extending.hs

@@ -1156,6 +1156,9 @@ A non complete list with a brief description:
     A module for abstracting a font facility over
     Core fonts and Xft.
 
+* "XMonad.Util.Hacks":
+    A collection of small fixes and utilities with possibly hacky implementations.
+
 * "XMonad.Util.Image":
     Utilities for manipulating [[Bool]] as images.
 

XMonad/Util/Hacks.hs

@@ -0,0 +1,74 @@
+-----------------------------------------------------------------------------
+-- |
+-- Module      :  XMonad.Util.Hacks
+-- Copyright   :  (c) 2020 Leon Kowarschick
+-- License     :  BSD3-style (see LICENSE)
+--
+-- Maintainer  :  Leon Kowarschick. <thereal.elkowar@gmail.com>
+-- Stability   :  unstable
+-- Portability :  unportable
+--
+-- This module is a collection of random fixes, workarounds and other functions
+-- that rely on somewhat hacky implementations which may have unwanted side effects.
+--
+-- Import this module as qualified like so:
+--
+-- > import qualified XMonad.Util.Hacks as Hacks
+--
+-- and then use the functions you want as described in their respective documentation.
+--
+-----------------------------------------------------------------------------
+
+module XMonad.Util.Hacks
+  ( -- * Windowed fullscreen
+    -- $windowedFullscreenFix
+    windowedFullscreenFixEventHook
+  ) where
+
+
+import XMonad
+import Data.Monoid (All(All))
+import Control.Monad (when)
+
+
+-- $windowedFullscreenFix
+-- Windowed fullscreen describes the behaviour in which XMonad,
+-- by default, does not automatically put windows that request being fullscreened
+-- into actual fullscreen, but keeps them constrained
+-- to their normal window dimensions, still rendering them in fullscreen.
+--
+-- With chromium based applications like Chrome, Discord and others this
+-- can cause issues, where the window does not correctly see the size of the window
+-- when displaying the fullscreen content, thus cutting off the window content.
+--
+-- This function works around that issue by forcing the window to recalculate their
+-- dimensions after initiating fullscreen, thus making chrome-based applications
+-- behave properly when in windowed fullscreen.
+--
+-- The following gif shows the behaviour of chrome (left) without this fix
+-- compared to firefox, which already behaves as expected by default:
+-- <<https://user-images.githubusercontent.com/5300871/99186015-b9512500-274d-11eb-9cfc-6ba3bae6db51.gif>>
+--
+-- Using this function, chrome will now behave as expected as well:
+-- <<https://user-images.githubusercontent.com/5300871/99186115-4dbb8780-274e-11eb-9ed2-b7815ba9e597.gif>>
+--
+-- Usage:
+-- add to handleEventHook as follows:
+--
+-- > handleEventHook = handleEventHook def <+> Hacks.windowedFullscreenFixEventHook
+--
+
+-- | Fixes fullscreen behaviour of chromium based apps by quickly applying and undoing a resize.
+-- This causes chromium to recalculate the fullscreen window
+-- dimensions to match the actual "windowed fullscreen" dimensions.
+windowedFullscreenFixEventHook :: Event -> X All
+windowedFullscreenFixEventHook (ClientMessageEvent _ _ _ dpy win typ (_:dats)) = do
+  wmstate <- getAtom "_NET_WM_STATE"
+  fullscreen <- getAtom "_NET_WM_STATE_FULLSCREEN"
+  when (typ == wmstate && fromIntegral fullscreen `elem` dats) $ do
+    withWindowAttributes dpy win $ \attrs ->
+      liftIO $ do
+        resizeWindow dpy win (fromIntegral $ wa_width attrs - 1) (fromIntegral $ wa_height attrs)
+        resizeWindow dpy win (fromIntegral $ wa_width attrs) (fromIntegral $ wa_height attrs)
+  return $ All True
+windowedFullscreenFixEventHook _ = return $ All True