Restart all xmobars on every XMonad screen change

dynamicEasySBs kept bars for existing screen ids, so the bar started
before screen-layout ran kept the laptop config on HDMI.

.config/xmonad/xmonad.hs

@@ -35,7 +35,8 @@ main =
     . ewmhFullscreen
     . setEwmhSwitchDesktopHook W.greedyView
     . ewmh
-    . dynamicEasySBs myStatusBars
+    . docks
+    . addAfterRescreenHook restartStatusBars
     . addRandrChangeHook (spawn myScreenHotplug)
     $ myConfig
 
@@ -182,13 +183,20 @@ myLayoutHook = onWorkspace wsWeb myWebLayout $ onWorkspace wsGames myGamesLayout
     delta = 3 / 100
 
 -- Xmobar
--- One bar per connected screen. The laptop config leaves room for trayer, so it
+-- The laptop config leaves room for trayer, so it goes on the laptop screen,
--- goes on the laptop screen, which is screen 1 with HDMI and screen 0 without.
+-- which is screen 1 with HDMI and screen 0 without.
-myStatusBars :: ScreenId -> X StatusBarConfig
+myStatusBar :: Int -> Int -> String
-myStatusBars (S i) = do
+myStatusBar nScreens i = "xmobar -x " ++ show i ++ " ~/.config/xmobar/" ++ rc
-  nScreens <- gets (length . W.screens . windowset)
+  where
-  let rc = if nScreens > 1 && i /= 1 then "xmobarrc_hdmi" else "xmobarrc_laptop"
+    rc = if nScreens > 1 && i /= 1 then "xmobarrc_hdmi" else "xmobarrc_laptop"
-  pure $ statusBarProp ("xmobar -x " ++ show i ++ " ~/.config/xmobar/" ++ rc) (clickablePP myXmobarPP)
+
+-- One bar per screen, all restarted on every screen change: the right config for a
+-- screen id depends on the screen count, and dynamicSBs would keep the old bar
+restartStatusBars :: X ()
+restartStatusBars = do
+  killAllStatusBars
+  screens <- gets (W.screens . windowset)
+  forM_ screens $ \s -> let S i = W.screen s in spawnStatusBar (myStatusBar (length screens) i)
 
 myXmobarPP :: PP
 myXmobarPP =
@@ -219,6 +227,7 @@ myXmobarPP =
 -- Autostart
 myStartupHook :: X ()
 myStartupHook = do
+  restartStatusBars
   spawnOnce myScreenSetup
   spawnOnce "xsetroot -cursor_name left_ptr"
   spawnOnce "xautolock -time 10 -locker slock -detectsleep"
@@ -289,7 +298,9 @@ myHandleEventHook =
 
 -- Log hook
 myLogHook :: X ()
-myLogHook = raiseDiscoverOverlay
+myLogHook = do
+  raiseDiscoverOverlay
+  xmonadPropLog =<< dynamicLogString =<< clickablePP myXmobarPP
 
 -- discover-overlay's windows are override-redirect, so xmonad doesn't manage them and
 -- raising a floating window (e.g. a game) covers them; put them back on top after every change