Locks: Implement event-driven locks indicator

This commit does more fundamental rework of the "Locks" plug-in: now the
plug-in is fully event-driven and thus extremely power-efficient,
effectively zero CPU consumption while idling.

2 files changed, 11 insertions, 3 deletions

diff --git a/src/Plugins/Kbd.hsc b/src/Plugins/Kbd.hsc
index 241dde4..318effc 100644
--- a/src/Plugins/Kbd.hsc
+++ b/src/Plugins/Kbd.hsc
@@ -276,6 +276,9 @@ xkbUseCoreKbd = #const XkbUseCoreKbd
 xkbStateNotify :: CUInt
 xkbStateNotify = #const XkbStateNotify
 
+xkbIndicatorStateNotify :: CUInt
+xkbIndicatorStateNotify = #const XkbIndicatorStateNotify
+
 xkbMapNotify :: CUInt
 xkbMapNotify = #const XkbMapNotify
 
diff --git a/src/Plugins/Locks.hs b/src/Plugins/Locks.hs
index b30eb1b..79b1583 100644
--- a/src/Plugins/Locks.hs
+++ b/src/Plugins/Locks.hs
@@ -20,6 +20,8 @@ import Data.Bits
 import Control.Monad
 import Graphics.X11.Xlib.Extras
 import Plugins
+import Plugins.Kbd
+import XUtil (nextEvent')
 
 data Locks = Locks
     deriving (Read, Show)
@@ -46,14 +48,17 @@ run' d root = do
 
 instance Exec Locks where
     alias Locks = "locks"
-    rate Locks = 2
     start Locks cb = do
         d <- openDisplay ""
         root <- rootWindow d (defaultScreen d)
+        _ <- xkbSelectEventDetails d xkbUseCoreKbd xkbIndicatorStateNotify m m
 
-        forever $ do
+        allocaXEvent $ \ep -> forever $ do
             cb =<< run' d root
-            tenthSeconds $ rate Locks
+            nextEvent' d ep
+            getEvent ep
 
         closeDisplay d
         return ()
+      where
+        m = xkbAllStateComponentsMask