Add new module XMonad.Hooks.WindowedFullscreenFix

CHANGES.md

@@ -46,12 +46,16 @@
 
 ### New Modules
 
+  * `XMonad.Hooks.WindowedFullscreenFix`
+
+    Provides a handleEventHook that fixes the rendering behaviour
+    of some (mostly chromium based) applications when in windowed fullscreen.
+
   * `XMonad.Util.ActionCycle`
 
     A module providing a simple way to implement "cycling" `X` actions,
     useful for things like alternating toggle-style keybindings.
 
-
   * `XMonad.Actions.RotateSome`
 
     Functions for rotating some elements around the stack while keeping others

XMonad/Doc/Extending.hs

@@ -575,6 +575,10 @@ Here is a list of the modules found in @XMonad.Hooks@:
 * "XMonad.Hooks.WorkspaceHistory":
     Keeps track of workspace viewing order.
 
+* "XMonad.Hooks.WindowedFullscreenFix":
+    Provides a handleEventHook that fixes the rendering behaviour
+    of some (mostly chromium based) applications when in windowed fullscreen.
+
 * "XMonad.Hooks.WindowSwallowing"
     A handleEventHook that implements window swallowing:
     Hide parent windows like terminals when opening other programs (like image viewers) from within them,

XMonad/Hooks/WindowedFullscreenFix.hs

@@ -0,0 +1,60 @@
+
+-----------------------------------------------------------------------------
+-- |
+-- Module      :  XMonad.Hooks.WindowedFullscreenFix
+-- Copyright   :  (c) 2020 Leon Kowarschick
+-- License     :  BSD3-style (see LICENSE)
+--
+-- Maintainer  :  Leon Kowarschick. <thereal.elkowar@gmail.com>
+-- Stability   :  unstable
+-- Portability :  unportable
+--
+-- 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 noral 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 module 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.
+-----------------------------------------------------------------------------
+module XMonad.Hooks.WindowedFullscreenFix
+  ( -- * Usage
+    -- $usage
+    windowedFullscreenFixEventHook
+  ) where
+
+
+import XMonad
+import Data.Monoid (All(All))
+import Control.Monad (when)
+
+
+-- $usage
+-- Use this module by importing
+--
+-- > import XMonad.Hooks.WindowedFullscreenFix
+--
+-- and then registering the provided eventHook in your handleEventHook:
+--
+-- > handleEventHook = handleEventHook def <+> 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 $ resizeWindow dpy win (fromIntegral $ wa_width attrs - 1) (fromIntegral $ wa_height attrs)
+    withWindowAttributes dpy win $ \attrs ->
+      liftIO $ resizeWindow dpy win (fromIntegral $ wa_width attrs + 1) (fromIntegral $ wa_height attrs)
+  return $ All True
+windowedFullscreenFixEventHook _ = return $ All True

xmonad-contrib.cabal

@@ -192,6 +192,7 @@ library
                         XMonad.Hooks.WallpaperSetter
                         XMonad.Hooks.WorkspaceByPos
                         XMonad.Hooks.WorkspaceHistory
+                        XMonad.Hooks.WindowedFullscreenFix
                         XMonad.Hooks.WindowSwallowing
                         XMonad.Hooks.XPropManage
                         XMonad.Layout.Accordion