mixer-wrapper: Add script to restart a long runnning amixerHEADmaster

We want a long running amixer, becuase the volume of the left and right
channel differ after multiple changes in short time. But on pulseaudio
restart we also have to restart amixer or no volume change could be
performed anymore.

2 files changed, 43 insertions, 2 deletions

diff --git a/bin/dzen2_pgrp.sh b/bin/dzen2_pgrp.sh
index 277a197..61349b1 100644
--- a/bin/dzen2_pgrp.sh
+++ b/bin/dzen2_pgrp.sh
@@ -27,8 +27,9 @@ OFFSET=$((OFFSET - 17))
 $DIR/bin/pulse-dbus-receive.py | \
 	$DZEN2 -xs "$SCREEN" -x "$OFFSET" -tw 17 -w 100 -fn "$FONT" -bg black -sa c -l 1 \
 		-e "entertitle=uncollapse,unhide;leavetitle=collapse;button2=exec:pavucontrol\
-		    ;button1=exec:$MIXER toggle;button3=exec:$MIXER 80%\
-		    ;button4=exec:$MIXER 2%+;button5=exec:$MIXER 2%-" &
+		    ;button1=print:sset Master toggle;button3=print:sset Master 80%\
+		    ;button4=print:sset Master 2%+;button5=print:sset Master 2%-" |
+	$DIR/bin/mixer-wrapper.py "amixer -s" &
 
 # fill the rest of the screen with the information from xmonad
 cat $* | $DZEN2 -xs "$SCREEN" -x 0 -w "$OFFSET" -ta l -fn "$FONT" -bg black -e 'button1=none' &
diff --git a/bin/mixer-wrapper.py b/bin/mixer-wrapper.py
new file mode 100755
index 0000000..1424f36
--- /dev/null
+++ b/bin/mixer-wrapper.py
@@ -0,0 +1,40 @@
+#!/usr/bin/python2
+
+import os
+import select
+import sys
+import subprocess
+import termios
+import pty
+from itertools import chain
+
+def main(cmd=None):
+    (pipe_in, pipe_out) = pty.openpty()
+    pipe = os.fdopen(pipe_in)
+
+    mixer = subprocess.Popen(sys.argv[1], stdin=subprocess.PIPE,
+                             stdout=pipe_out, stderr=subprocess.STDOUT,
+                             shell=True, bufsize=0, close_fds=True)
+
+    input = iter(sys.stdin.readline, '')
+    if cmd is not None:
+        input = chain([cmd], input)
+
+    for line in input:
+        mixer.stdin.write(b"%s\n" % line)
+        mixer.stdin.flush()
+ 
+        termios.tcflush(pipe_in, termios.TCIFLUSH)
+        fds = select.select([pipe_in], [], [], 0.2)[0]
+        if len(fds) <= 0:
+            mixer.stdin.close()
+            mixer.wait()
+            if cmd is None or line != cmd:
+                return line
+            return None
+
+
+if __name__ == '__main__':
+    cmd = None
+    while True:
+        cmd = main(cmd)