improvements to XMonad.Hooks.DynamicLog, and new contrib module XMonad.Util.Loggers

Improvements to DynamicLog include:
  * Greatly expanded and improved documentation and examples
  * remove seemingly useless makeSimpleDzenConfig function
  * factor out xmobarPP
  * add new ppExtras field to PP record, for specifying 'extra'
    loggers which can supply information other than window title,
    layout, and workspace status to a status bar (for example, time and date,
    battery status, mail status, etc.)

The new XMonad.Util.Loggers module provides some example loggers that
can be used in the new ppExtras field of the PP record.  Create your own,
add them to this module, go crazy!

darcs-hash:20080219210128-bd4d7-33f4bcf2732069a5b7cf7584efa6ee060604c40b.gz

1 files changed, 88 insertions, 0 deletions

diff --git a/XMonad/Util/Loggers.hs b/XMonad/Util/Loggers.hs
new file mode 100644
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+++ b/XMonad/Util/Loggers.hs
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+-----------------------------------------------------------------------------
+-- |
+-- Module      :  XMonad.Util.Loggers
+-- Copyright   :  (c) Brent Yorgey
+-- License     :  BSD-style (see LICENSE)
+--
+-- Maintainer  :  <byorgey@gmail.com>
+-- Stability   :  unstable
+-- Portability :  unportable
+--
+-- A collection of simple logger functions which can be used in the
+-- 'XMonad.Hooks.DynamicLog.ppExtras' field of a pretty-printing status
+-- logger format. See "XMonad.Hooks.DynamicLog" for more information.
+-----------------------------------------------------------------------------
+
+module XMonad.Util.Loggers (
+                            -- * Usage
+                            -- $usage
+
+                             Logger
+
+                           , date
+                           , loadAvg
+                           , battery
+                           , logCmd
+
+                           ) where
+
+import XMonad.Core
+
+import System.Time
+import System.IO
+import System.Process
+import System.Locale
+
+-- $usage
+-- You can use this module by importing it into your @~\/.xmonad\/xmonad.hs@:
+--
+-- > import XMonad.Util.Loggers
+--
+-- Then, add one or more loggers to the
+-- 'XMonad.Hooks.DynamicLog.ppExtras' field of your
+-- 'XMonad.Hooks.DynamicLoc.PP' format.  For example:
+--
+-- >     -- display load averages and a pithy quote along with xmonad status.
+-- >   , logHook = dynamicLogWithPP $ defaultPP { ppExtras = [ loadAvg, logCmd "fortune -n 40 -s" ] }
+--
+-- Of course, there is nothing really special about these so-called
+-- \'loggers\': they are just @X (Maybe String)@ actions.  So you can
+-- use them anywhere you would use an @X (Maybe String)@, not just
+-- with DynamicLog.
+--
+-- Additional loggers welcome!
+--
+
+-- | 'Logger' is just a convenient synonym for @X (Maybe String)@.
+type Logger = X (Maybe String)
+
+-- | Get the current date and time, and format them via the
+--   given format string.  The format used is the same as that used
+--   by the C library function strftime; for example,
+--   @date \"%a %b %d\"@ might display something like @Tue Feb 19@.
+--   For more information see something like
+--   <http://www.cplusplus.com/reference/clibrary/ctime/strftime.html>.
+date :: String -> Logger
+date fmt = io $ do cal <- (getClockTime >>= toCalendarTime)
+                   return . Just $ formatCalendarTime defaultTimeLocale fmt cal
+
+-- | Get the load average.  This assumes that you have a
+--   utility called @\/usr\/bin\/uptime@ and that you have @sed@
+--   installed; these are fairly common on GNU\/Linux systems but it
+--   would be nice to make this more general.
+loadAvg :: Logger
+loadAvg = logCmd "/usr/bin/uptime | sed 's/.*: //; s/,//g'"
+
+-- | Get the battery status (percent charge and charging\/discharging
+--   status). This is an ugly hack and may not work for some people.
+--   At some point it would be nice to make this more general\/have
+--   fewer dependencies.
+battery :: Logger
+battery = logCmd "/usr/bin/acpi | sed -r 's/.*?: (.*%).*/\\1/; s/discharging, ([0-9]+%)/\\1-/; s/charging, ([0-9]+%)/\\1+/; s/charged, //'"
+
+-- | Create a 'Logger' from an arbitrary shell command.
+logCmd :: String -> Logger
+logCmd c = io $ do (_, out, _, proc) <- runInteractiveCommand c
+                   output <- hGetLine out
+                   waitForProcess proc
+                   return $ Just output