Monitor combiners (eventually to xmobar)

1 files changed, 33 insertions, 0 deletions

diff --git a/src/lib/Monitors.hs b/src/lib/Monitors.hs
index 15900e5..fb51893 100644
--- a/src/lib/Monitors.hs
+++ b/src/lib/Monitors.hs
@@ -2,6 +2,39 @@ module Monitors where
 
 import Xmobar
 import Config
+import Control.Concurrent
+import Control.Concurrent.Async (async)
+import Control.Concurrent.STM
+
+data CombinedMonitor a b = CombinedMonitor a b (String -> String -> String)
+
+instance (Show a, Show b) => Show (CombinedMonitor a b) where
+  show (CombinedMonitor a b _) = "Alt (" ++ show a ++ ") (" ++ show b ++ ")"
+
+instance (Read a, Read b) => Read (CombinedMonitor a b) where
+  readsPrec _ = undefined
+
+instance (Exec a, Exec b) => Exec (CombinedMonitor a b) where
+  alias (CombinedMonitor a b _) = (alias a) ++ "_" ++ (alias b)
+  rate (CombinedMonitor a b _) = min (rate a) (rate b)
+  start (CombinedMonitor a b comb) cb
+    = startMonitors a b (\s t -> cb $ comb s t)
+
+startMonitors a b cmb =  do
+    sta <- atomically $ newTVar ""
+    stb <- atomically $ newTVar ""
+    _ <- async $ start a (\x -> atomically $ writeTVar sta x)
+    _ <- async $ start b (\x -> atomically $ writeTVar stb x)
+    go sta stb cmb
+      where go sta' stb' cmb' = do
+              s <- atomically $ readTVar sta'
+              t <- atomically $ readTVar stb'
+              cmb' s t
+              tenthSeconds $ min (rate b) (rate a)
+              go sta' stb' cmb'
+
+altMonitor a b = CombinedMonitor a b (\s t -> if null s then t else s)
+concatMonitor sep a b = CombinedMonitor a b (\s t -> s ++ sep ++ t)
 
 topProc p = TopProc (p <~> ["-t" , "<mboth3>  <mboth2>  <mboth1> \
                                    \· <both3>  <both2>  <both1>"