From fd5d8267d2369d7b6f11b0b6dcbcaac834ddf9c8 Mon Sep 17 00:00:00 2001
From: slotThe <soliditsallgood@mailbox.org>
Date: Sat, 15 May 2021 15:19:34 +0200
Subject: [PATCH 1/2] Set WM_CLASS for created windows

Set the WM_CLASS property for long-living windows that need it.  This
helps users to properly match on these windows for certain tasks.

Fixes:
  - https://github.com/xmonad/xmonad-contrib/issues/526
  - https://github.com/xmonad/xmonad-contrib/issues/369
---
 XMonad/Actions/TreeSelect.hs | 4 +++-
 XMonad/Layout/Decoration.hs  | 8 ++++++--
 XMonad/Prompt.hs             | 7 ++++---
 3 files changed, 13 insertions(+), 6 deletions(-)

diff --git a/XMonad/Actions/TreeSelect.hs b/XMonad/Actions/TreeSelect.hs
index 4d7ca970..f243787a 100644
--- a/XMonad/Actions/TreeSelect.hs
+++ b/XMonad/Actions/TreeSelect.hs
@@ -317,7 +317,9 @@ treeselectAt conf@TSConfig{..} zipper hist = withDisplay $ \display -> do
         set_colormap attributes colormap
         set_background_pixel attributes ts_background
         set_border_pixel attributes 0
-        createWindow display rootw rect_x rect_y rect_width rect_height 0 (visualInfo_depth vinfo) inputOutput (visualInfo_visual vinfo) (cWColormap .|. cWBorderPixel .|. cWBackPixel) attributes
+        w <- createWindow display rootw rect_x rect_y rect_width rect_height 0 (visualInfo_depth vinfo) inputOutput (visualInfo_visual vinfo) (cWColormap .|. cWBorderPixel .|. cWBackPixel) attributes
+        setClassHint display w (ClassHint "xmonad-tree_select" "xmonad")
+        pure w
 
     liftIO $ do
         -- TODO: move below?
diff --git a/XMonad/Layout/Decoration.hs b/XMonad/Layout/Decoration.hs
index bd4fbc8c..54c0a25a 100644
--- a/XMonad/Layout/Decoration.hs
+++ b/XMonad/Layout/Decoration.hs
@@ -377,8 +377,12 @@ createDecos t ds sc s wrs ((w,r):xs) = do
 createDecos _ _ _ _ _ [] = return []
 
 createDecoWindow :: Theme -> Rectangle -> X Window
-createDecoWindow t r = let mask = Just (exposureMask .|. buttonPressMask) in
-                       createNewWindow r mask (inactiveColor t) True
+createDecoWindow t r = do
+  let mask = Just (exposureMask .|. buttonPressMask)
+  w <- createNewWindow r mask (inactiveColor t) True
+  d <- asks display
+  io $ setClassHint d w (ClassHint "xmonad-decoration" "xmonad")
+  pure w
 
 showDecos :: [DecoWin] -> X ()
 showDecos = showWindows . catMaybes . map fst . filter (isJust . snd)
diff --git a/XMonad/Prompt.hs b/XMonad/Prompt.hs
index fa0efdd4..33982aa2 100644
--- a/XMonad/Prompt.hs
+++ b/XMonad/Prompt.hs
@@ -558,7 +558,7 @@ mkXPromptImplementation historyKey conf om = do
   fs <- initXMF (font conf)
   st' <- io $
     bracket
-      (createWin d rw conf s)
+      (createPromptWin d rw conf s)
       (destroyWindow d)
       (\w ->
         bracket
@@ -1395,8 +1395,8 @@ redrawWindows c = do
     l  -> redrawComplWin l
   io $ sync d False
 
-createWin :: Display -> Window -> XPConfig -> Rectangle -> IO Window
-createWin d rw c s = do
+createPromptWin :: Display -> Window -> XPConfig -> Rectangle -> IO Window
+createPromptWin d rw c s = do
   let (x,y) = case position c of
                 Top -> (0,0)
                 Bottom -> (0, rect_height s - height c)
@@ -1406,6 +1406,7 @@ createWin d rw c s = do
                 _              -> rect_width s
   w <- mkUnmanagedWindow d (defaultScreenOfDisplay d) rw
                       (rect_x s + x) (rect_y s + fi y) width (height c)
+  setClassHint d w (ClassHint "xmonad-prompt" "xmonad")
   mapWindow d w
   return w
 

From f19b3f6de3f765638203658bbdc8f5a53cf91f0f Mon Sep 17 00:00:00 2001
From: slotThe <soliditsallgood@mailbox.org>
Date: Sat, 15 May 2021 15:42:14 +0200
Subject: [PATCH 2/2] Update CHANGES.md

---
 CHANGES.md | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/CHANGES.md b/CHANGES.md
index ded0d27c..60d9cea4 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -27,6 +27,9 @@
       constraint (was: `IO`), due to changes in how the xmonad core handles XDG
       directories.
 
+    - The prompt window now sets a `WM_CLASS` property.  This allows
+      other applications, like compositors, to properly match on it.
+
   * `XMonad.Hooks.EwmhDesktops`
 
     - It is no longer recommended to use `fullscreenEventHook` directly.
@@ -251,6 +254,10 @@
 
     - Fix swapped green/blue in foreground when using Xft.
 
+    - The spawned tree-select window now sets a `WM_CLASS` property.
+      This allows other applications, like compositors, to properly
+      match on it.
+
   * `XMonad.Layout.Fullscreen`
 
     - Add fullscreenSupportBorder which uses smartBorders to remove
@@ -572,6 +579,11 @@
     - Add the ability to increase/decrease the window size by a custom
       rational number. E.g: `sendMessage $ ExpandTowardsBy L 0.02`
 
+  * `XMonad.Layout.Decoration`
+
+    - The decoration window now sets a `WM_CLASS` property.  This allows
+      other applications, like compositors, to properly match on it.
+
 ## 0.16
 
 ### Breaking Changes