From fa82db1130258d83014ab6769a5297552c53242b Mon Sep 17 00:00:00 2001
From: Evgeny Kurnevsky <kurnevsky@gmail.com>
Date: Tue, 29 Jun 2021 21:59:09 +0300
Subject: [PATCH] Change EWMH windows ordering to be closer to the spec.

---
 CHANGES.md                   |  4 ++++
 XMonad/Hooks/EwmhDesktops.hs | 28 +++++++++++++++++++++++-----
 2 files changed, 27 insertions(+), 5 deletions(-)

diff --git a/CHANGES.md b/CHANGES.md
index 2212c012..9dacf86c 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -47,6 +47,10 @@
       activation behavior and then add resulting `ManageHook` using
       `activateLogHook` to your `logHook`. Also, module `X.H.Focus` provides
       additional combinators.
+      
+    - Ordering of windows that are set to `_NET_CLIENT_LIST` and `_NET_CLIENT_LIST_STACKING`
+      was changed to be closer to the spec. From now these two lists will have
+      differently sorted windows.
 
   * All modules still exporting a `defaultFoo` constructor
 
diff --git a/XMonad/Hooks/EwmhDesktops.hs b/XMonad/Hooks/EwmhDesktops.hs
index 69123303..c6cfd5a2 100644
--- a/XMonad/Hooks/EwmhDesktops.hs
+++ b/XMonad/Hooks/EwmhDesktops.hs
@@ -123,6 +123,14 @@ newtype ClientList = ClientList [Window]
 instance ExtensionClass ClientList where
     initialValue = ClientList [none]
 
+-- |
+-- Cached stacking client list (e.g. @_NET_CLIENT_LIST_STACKING@).
+newtype ClientListStacking = ClientListStacking [Window]
+                           deriving Eq
+
+instance ExtensionClass ClientListStacking where
+    initialValue = ClientListStacking [none]
+
 -- |
 -- Cached current desktop (e.g. @_NET_CURRENT_DESKTOP@).
 newtype CurrentDesktop = CurrentDesktop Int
@@ -171,10 +179,17 @@ ewmhDesktopsLogHookCustom t = withWindowSet $ \s -> do
         setNumberOfDesktops (length desktopNames)
         setDesktopNames desktopNames
 
-    -- Set client list; all windows, with focused windows last
-    let clientList = nub . concatMap (maybe [] (\(W.Stack x l r) -> reverse l ++ r ++ [x]) . W.stack) $ ws
+    -- Set client list which should be sorted by window age. We just
+    -- guess that StackSet contains windows list in this order which
+    -- isn't true but at least gives consistency with windows cycling
+    let clientList = nub . concatMap (W.integrate' . W.stack) $ ws
     whenChanged (ClientList clientList) $ setClientList clientList
 
+    -- Set stacking client list which should have bottom-to-top
+    -- stacking order, i.e. focused window should be last
+    let clientListStacking = nub . concatMap (maybe [] (\(W.Stack x l r) -> reverse l ++ r ++ [x]) . W.stack) $ ws
+    whenChanged (ClientListStacking clientListStacking) $ setClientListStacking clientListStacking
+
     -- Remap the current workspace to handle any renames that f might be doing.
     let maybeCurrent' = W.tag <$> listToMaybe (t [W.workspace $ W.current s])
         current = flip elemIndex (map W.tag ws) =<< maybeCurrent'
@@ -354,12 +369,15 @@ setDesktopNames names = withDisplay $ \dpy -> do
 
 setClientList :: [Window] -> X ()
 setClientList wins = withDisplay $ \dpy -> do
-    -- (What order do we really need? Something about age and stacking)
     r <- asks theRoot
     a <- getAtom "_NET_CLIENT_LIST"
     io $ changeProperty32 dpy r a wINDOW propModeReplace (fmap fromIntegral wins)
-    a' <- getAtom "_NET_CLIENT_LIST_STACKING"
-    io $ changeProperty32 dpy r a' wINDOW propModeReplace (fmap fromIntegral wins)
+
+setClientListStacking :: [Window] -> X ()
+setClientListStacking wins = withDisplay $ \dpy -> do
+    r <- asks theRoot
+    a <- getAtom "_NET_CLIENT_LIST_STACKING"
+    io $ changeProperty32 dpy r a wINDOW propModeReplace (fmap fromIntegral wins)
 
 setWindowDesktop :: (Integral a) => Window -> a -> X ()
 setWindowDesktop win i = withDisplay $ \dpy -> do