From 30c1202c3b6e9c45deaabfbaf2fb43d8c78ed5c6 Mon Sep 17 00:00:00 2001 From: Anton Vorontsov Date: Mon, 1 Sep 2014 09:21:58 +0200 Subject: Implement proper handling of dynamically changing hostname Ignore-this: 2aeac6d2161e666d40cda6a09f78b208 The module implements a proper way of finding out whether the window is remote or local. Just checking for a hostname and WM_CLIENT_MACHINE being equal is often not enough because the hostname is a changing subject (without any established notification mechanisms), and thus WM_CLIENT_MACHINE and the hostname can diverge even for a local window. This module solves the problem. As soon as there is a new window created, we check the hostname and WM_CLIENT_MACHINE, and then we cache the result into the XMONAD_REMOTE property. Notice that XMonad itself does not know anything about hostnames, nor does it have any dependency on Network.* modules. For this module it is not a problem: you can provide a mean to get the hostname through your config file (see usage). Or, if you don't like the hassle of handling dynamic hostnames (suppose your hostname never changes), it is also fine: this module will fallback to using environment variables. darcs-hash:20140901072158-1836e-fa2b05c79ec3217d5024b7e050b2239dcf7de4b4.gz --- XMonad/Layout/Stoppable.hs | 15 +++----- XMonad/Util/RemoteWindows.hs | 90 ++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 96 insertions(+), 9 deletions(-) create mode 100644 XMonad/Util/RemoteWindows.hs (limited to 'XMonad') diff --git a/XMonad/Layout/Stoppable.hs b/XMonad/Layout/Stoppable.hs index 35c3c01..5c95aa1 100644 --- a/XMonad/Layout/Stoppable.hs +++ b/XMonad/Layout/Stoppable.hs @@ -46,10 +46,10 @@ module XMonad.Layout.Stoppable import XMonad import XMonad.Actions.WithAll import XMonad.Util.WindowProperties +import XMonad.Util.RemoteWindows import XMonad.Util.Timer import XMonad.StackSet hiding (filter) import XMonad.Layout.LayoutModifier -import System.Posix.Env import System.Posix.Signals import Data.Maybe import Control.Monad @@ -67,8 +67,10 @@ import Control.Monad -- proccesses, which means that it needs to know the hostname, so it looks -- for environment variables (e.g. HOST). -- --- Beware that as of now this module does not support dynamically changing --- hostnames. +-- Environment variables will work for most cases, but won't work if the +-- hostname changes. To cover dynamic hostnames case, in addition to +-- layoutHook you have to provide manageHook from +-- "XMonad.Util.RemoteWindows" module. -- -- For more detailed instructions on editing the layoutHook see: -- @@ -80,12 +82,7 @@ signalWindow s w = do io $ (signalProcess s . fromIntegral) `mapM_` fromMaybe [] pid signalLocalWindow :: Signal -> Window -> X () -signalLocalWindow s w = do - host <- io $ pickOneMaybe `liftM` (getEnv `mapM` vars) - hasProperty (Machine host) w >>= flip when (signalWindow s w) - where - pickOneMaybe = last . (mzero:) . take 1 . catMaybes - vars = ["XAUTHLOCALHOSTNAME","HOST","HOSTNAME"] +signalLocalWindow s w = isLocalWindow w >>= flip when (signalWindow s w) withAllOn :: (a -> X ()) -> Workspace i l a -> X () withAllOn f wspc = f `mapM_` integrate' (stack wspc) diff --git a/XMonad/Util/RemoteWindows.hs b/XMonad/Util/RemoteWindows.hs new file mode 100644 index 0000000..8eeb025 --- /dev/null +++ b/XMonad/Util/RemoteWindows.hs @@ -0,0 +1,90 @@ +----------------------------------------------------------------------------- +-- | +-- Module : XMonad.Util.RemoteWindows +-- Copyright : (c) Anton Vorontsov 2014 +-- License : BSD-style (as xmonad) +-- +-- Maintainer : Anton Vorontsov +-- Stability : unstable +-- Portability : unportable +-- +-- This module implements a proper way of finding out whether the window +-- is remote or local. +-- +-- Just checking for a hostname and WM_CLIENT_MACHINE being equal is often +-- not enough because the hostname is a changing subject (without any +-- established notification mechanisms), and thus WM_CLIENT_MACHINE and +-- the hostname can diverge even for a local window. +-- +-- This module solves the problem. As soon as there is a new window +-- created, we check the hostname and WM_CLIENT_MACHINE, and then we cache +-- the result into the XMONAD_REMOTE property. +-- +-- Notice that XMonad itself does not know anything about hostnames, nor +-- does it have any dependency on Network.* modules. For this module it is +-- not a problem: you can provide a mean to get the hostname through your +-- config file (see usage). Or, if you don't like the hassle of handling +-- dynamic hostnames (suppose your hostname never changes), it is also +-- fine: this module will fallback to using environment variables. +-- +----------------------------------------------------------------------------- + +module XMonad.Util.RemoteWindows + ( -- $usage + isLocalWindow + , manageRemote + , manageRemoteG + ) where + +import XMonad +import XMonad.Util.WindowProperties +import Data.Monoid +import Data.Maybe +import Control.Monad +import System.Posix.Env + +-- $usage +-- You can use this module with the following in your @~\/.xmonad\/xmonad.hs@: +-- +-- > import XMonad +-- > import XMonad.Util.RemoteWindows +-- > import Network.BSD +-- > +-- > main = xmonad def +-- > { manageHook = manageRemote =<< io getHostName } + +guessHostName :: IO String +guessHostName = pickOneMaybe `liftM` (getEnv `mapM` vars) + where + pickOneMaybe = last . (mzero:) . take 1 . catMaybes + vars = ["XAUTHLOCALHOSTNAME","HOST","HOSTNAME"] + +setRemoteProp :: Window -> String -> X () +setRemoteProp w host = do + d <- asks display + p <- getAtom "XMONAD_REMOTE" + t <- getAtom "CARDINAL" + v <- hasProperty (Machine host) w + io $ changeProperty32 d w p t propModeReplace + [fromIntegral . fromEnum $ not v] + +-- | Given a window, tell if it is a local or a remote process. Normally, +-- it checks XMONAD_REMOTE property. If it does not exist (i.e. the +-- manageRemote hook was not deployed in user's config), it falls back to +-- checking environment variables and assuming that hostname never +-- changes. +isLocalWindow :: Window -> X Bool +isLocalWindow w = getProp32s "XMONAD_REMOTE" w >>= \p -> case p of + Just [y] -> return $ y == 0 + _ -> io guessHostName >>= \host -> hasProperty (Machine host) w + +-- | Use this hook to let XMonad properly track remote/local windows. For +-- example, @manageHook = manageRemote =<< io getHostName@. +manageRemote :: String -> ManageHook +manageRemote host = ask >>= \w -> liftX (setRemoteProp w host) >> return mempty + +-- | Use this hook if you want to manage XMONAD_REMOTE properties, but +-- don't want to use an external getHostName in your config. That way you +-- are retreating to environment variables. +manageRemoteG :: ManageHook +manageRemoteG = manageRemote =<< io guessHostName -- cgit v1.2.3