From e3c9b33170f1064077aa8578342369657b9e059c Mon Sep 17 00:00:00 2001
From: Thomas Tuegel <ttuegel@gmail.com>
Date: Thu, 13 Jan 2011 10:34:09 -0600
Subject: Added volume monitor based on alsa-mixer.

---
 src/Plugins/Monitors.hs        | 12 ++++++++++++
 src/Plugins/Monitors/Volume.hs | 36 ++++++++++++++++++++++++++++++++++++
 xmobar.cabal                   |  8 ++++++++
 3 files changed, 56 insertions(+)
 create mode 100644 src/Plugins/Monitors/Volume.hs

diff --git a/src/Plugins/Monitors.hs b/src/Plugins/Monitors.hs
index 9887d74..14d97a2 100644
--- a/src/Plugins/Monitors.hs
+++ b/src/Plugins/Monitors.hs
@@ -38,6 +38,9 @@ import Plugins.Monitors.Wireless
 #ifdef LIBMPD
 import Plugins.Monitors.MPD
 #endif
+#ifdef ALSA
+import Plugins.Monitors.Volume
+#endif
 
 data Monitors = Weather  Station    Args Rate
               | Network  Interface  Args Rate
@@ -60,6 +63,9 @@ data Monitors = Weather  Station    Args Rate
 #endif
 #ifdef LIBMPD
               | MPD      Args       Rate
+#endif
+#ifdef ALSA
+              | Volume   String     String Args Rate
 #endif
                 deriving (Show,Read,Eq)
 
@@ -94,6 +100,9 @@ instance Exec Monitors where
 #endif
 #ifdef LIBMPD
     alias (MPD        _ _) = "mpd"
+#endif
+#ifdef ALSA
+    alias (Volume m c _ _) = m ++ ":" ++ c
 #endif
     start (Weather  s a r) = runM (a ++ [s]) weatherConfig  runWeather    r
     start (Network  i a r) = runM (a ++ [i]) netConfig      runNet        r
@@ -117,3 +126,6 @@ instance Exec Monitors where
 #ifdef LIBMPD
     start (MPD        a r) = runM a          mpdConfig      runMPD        r
 #endif
+#ifdef ALSA
+    start (Volume m c a r) = runM a          volumeConfig  (runVolume m c) r
+#endif
diff --git a/src/Plugins/Monitors/Volume.hs b/src/Plugins/Monitors/Volume.hs
new file mode 100644
index 0000000..c7814a8
--- /dev/null
+++ b/src/Plugins/Monitors/Volume.hs
@@ -0,0 +1,36 @@
+module Plugins.Monitors.Volume (runVolume, volumeConfig) where
+
+import Control.Monad ( liftM )
+import Data.Maybe
+import Plugins.Monitors.Common
+import Sound.ALSA.Mixer
+
+percent :: Integer -> Integer -> Integer -> Float
+percent v' lo' hi' = (v - lo) / (hi - lo)
+  where v = fromIntegral v'
+        lo = fromIntegral lo'
+        hi = fromIntegral hi'
+
+volumeConfig :: IO MConfig
+volumeConfig = mkMConfig "Vol: <volume>% <fc=green><on></fc><fc=red><off></fc>"
+                         ["volume","dB","on","off"]
+
+runVolume :: String -> String -> [String] -> Monitor String
+runVolume mixerName controlName _ = do
+    control <- liftM fromJust $ io $ getControlByName mixerName controlName
+    let volumeControl = fromJust $ maybe (playback $ volume control) Just
+                                         (common $ volume control)
+        switchControl = fromJust $ maybe (playback $ switch control) Just
+                                         (common $ switch control)
+    (lo, hi) <- io $ getRange volumeControl
+    val <- liftM fromJust $ io $ getChannel FrontLeft $ value volumeControl
+    db <- liftM fromJust $ io $ getChannel FrontLeft $ dB volumeControl
+    sw <- liftM fromJust $ io $ getChannel FrontLeft $ switchControl
+    p <- showPercentsWithColors [ percent val lo hi ]
+    let d :: Double
+        d = fromIntegral db / 100.0
+        dStr = showDigits 2 d
+    parseTemplate $ p ++ [ dStr ]
+                      ++ [ if sw then "[on] " else ""
+                         , if sw then "" else "[off]"
+                         ]
diff --git a/xmobar.cabal b/xmobar.cabal
index e5ee507..0eac0fa 100644
--- a/xmobar.cabal
+++ b/xmobar.cabal
@@ -53,6 +53,10 @@ flag all_extensions
   description: Includes all optional extensions.
   default: False
 
+flag with_alsa
+  description: Use alsa-mixer to get the volume from soundcards.
+  default: False
+
 executable xmobar
     hs-source-dirs:     src
     main-is:            Main.hs
@@ -109,3 +113,7 @@ executable xmobar
        build-depends: libmpd >= 0.5
        other-modules: Plugins.Monitors.MPD
        cpp-options: -DLIBMPD
+
+    if flag(with_alsa) || flag(all_extensions)
+       build-depends: alsa-mixer
+       cpp-options: -DALSA
-- 
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