Make it possible to delay Hide, Reveal and Toggle signals

Previously Hide, Reveal and Toggle were immediate actions. This is the
same behaviour as if called now with 0 as parameter.
If the parameter is a positive non zero value it is taken as a delay for
the requested action.
After the delay (implemented using threadDelay) a new signal is sent
with zero with no timeout being effective immediately. This is necessary
to evaluate the persistency flag after the delay because it might have
changed in the meantime.
Effectively this means that it is possible to cancel the delayed
operation by calling TogglePersistent.

1 files changed, 18 insertions, 7 deletions

diff --git a/src/Xmobar.hs b/src/Xmobar.hs
index 79234d2..f531cb4 100644
--- a/src/Xmobar.hs
+++ b/src/Xmobar.hs
@@ -146,9 +146,9 @@ eventLoop tv xc@(XConf d _ w fs cfg) signal = do
             ncfg <- updateConfigPosition cfg
             reposWindow ncfg
 
-         Hide ->   hide
-         Reveal -> reveal
-         Toggle -> toggle
+         Hide   t -> hide   (t*100*1000)
+         Reveal t -> reveal (t*100*1000)
+         Toggle t -> toggle (t*100*1000)
 
          TogglePersistent -> eventLoop
             tv xc { config = cfg { persistent = not $ persistent cfg } } signal
@@ -156,16 +156,27 @@ eventLoop tv xc@(XConf d _ w fs cfg) signal = do
     where
         isPersistent = not $ persistent cfg
 
-        hide   = when isPersistent (hideWindow d w) >> eventLoop tv xc signal
+        hide t | t == 0    = do
+            when isPersistent $ hideWindow d w
+            eventLoop tv xc signal
+               | otherwise = do
+            void $ forkIO
+                 $ threadDelay t >> atomically (putTMVar signal $ Hide 0)
+            eventLoop tv xc signal
 
-        reveal = if isPersistent
-            then do
+        reveal t | t == 0 =
+            if isPersistent
+                then do
                 r' <- repositionWin d w fs cfg
                 showWindow d w
                 eventLoop tv (XConf d r' w fs cfg) signal
             else eventLoop tv xc signal
+                 | otherwise = do
+            void $ forkIO
+                 $ threadDelay t >> atomically (putTMVar signal $ Reveal 0)
+            eventLoop tv xc signal
 
-        toggle = isMapped d w >>= \b -> if b then hide else reveal
+        toggle t = isMapped d w >>= \b -> if b then hide t else reveal t
 
         reposWindow rcfg = do
           r' <- repositionWin d w fs rcfg