How to float a window which has WM_NAME but no WM_CLASS

Question

Configuration

Debian Linux 8.2, 64bit, Xmonad 0.11

When it started

I recently upgraded my system (to debian8), so I had to make some adjustments to my xmonad.hs configuration - namely changing managehooks for GStreamer'sgst-launch windows from:

, title     =? "gst-launch-0.10" --> doFloat

to:

, title     =? "gst-launch-1.0" --> doFloat

I'm using title instead of className because gst-launch-1.0 windows have only this properties:

$ xprop
_NET_WM_DESKTOP(CARDINAL) = 6
WM_NAME(STRING) = "gst-launch-1.0"
WM_STATE(WM_STATE):
                window state: Normal
                icon window: 0x0
_MOTIF_WM_HINTS(_MOTIF_WM_HINTS) = 0x2, 0x0, 0x1, 0x0, 0x0
WM_PROTOCOLS(ATOM): protocols  WM_DELETE_WINDOW

What it does

I'm encountering very strange behaviour, which I haven't seen with the old gst-launch-0.10 windows. When gst-launch-1.0 window (usually quite small - 400x300) starts it is one of following cases with decreasing probability:

adds the window as another tile (no floating at all) and stretches its content to fill this tile (keeping aspect ratio), the rest of the tile is black
adds the window as another tile (no floating at all) but draws only in the top left corner of this tile (no stretching), the rest of the tile shows X-Window background
with less than 10% probability it floats the window properly

What I've tried

doFullFloat and doCenterFloat do exactly the same thing (except it's centered or full in the last case)

What I suspect

I'm pretty sure the problem is in using only WM_NAME/title instead of WM_CLASS/className/appName, because the title can be changed during the lifetime of the window. I think the gst-launch-1.0 window starts with some other (or none) title and after some time it switches to gst-launch-1.0. Then it's only matter of luck if xmonad catches the original title or the final gst-launch-1.0.

Question

Is there some way to "wait a while" in manageHook so I could be sure to catch the final window WM_NAME/title ?

Or any other idea?

Additional info:

Apparently this has been fixed in gstreamer - https://bugzilla.gnome.org/show_bug.cgi?id=750455 - but unfortunately I need to use gstreamer which comes with debian.

score 2 · Answer 1 · edited Jul 02 '22 at 11:10

This might be helpfull, the following is of type X () so can be binded to a keybinding.

withWindowSet
  $ (\ws -> case W.stack . W.workspace . W.current $ ws of
      Just w' ->
        mapM_
            (\w -> do
              s <- withDisplay
                $ \d -> fmap resClass $ liftIO $ getClassHint d w
              case (s) of
                "Emacs" -> do
                  windows $ W.focusWindow w
                "Lxterminal" -> do
                  wmName <- withDisplay
                    $ \d -> getStringProperty d w "WM_NAME"
                  case wmName of
                    Just "ranger" -> windows $ W.focusWindow w
            )
          $ W.integrate w'
      _ -> return ()
    )

The important lines are:

"Lxterminal" -> do
  wmName <- withDisplay $ \d -> getStringProperty d w "WM_NAME"
    case wmName of
      Just "ranger" -> windows $ W.focusWindow w

So we first match by WM_CLASS, and then WM_NAME.