put decorators into utils, added "register_if_installed"

dwmstat.py

@@ -5,26 +5,9 @@
 
 from utils import *
 
-PREVIOUS = object()
-
-_statuses = []
-_transitions = []
-
-# A decorator to add a function to our statuses list.
-def status_func(func):
-    global _statuses
-    _statuses.append(func)
-    return func
-
-# A decorator to add a function to our transitions list.
-def transition_func(func):
-    global _transitions
-    _transitions.append(func)
-    return func
+STATUSDELAY = 30
 
-# This function allows us to set the text of the status line.
-def dwm_set_status(text):
-    Popen(["xsetroot", "-name", text])
+PREVIOUS = object()
 
 def animate(delay, text):
     previous = yield PREVIOUS
@@ -36,7 +19,6 @@ def wait(delay, text):
     yield text
     sleep(delay)
 
-
 # install a few status functions
 
 # Status functions call one of these helper functions and yield the result:
@@ -69,7 +51,7 @@ def memory_free():
     yield animate(5, "Used Swap Space")
     yield animate(5, pretty_progressbar(used_swap, 80))
 
-@status_func
+@register_if_installed("mpc")
 def mpd_np():
     try:
         status_output = Popen(["mpc", "status"], stdout=PIPE).communicate()[0]
@@ -87,7 +69,7 @@ def mpd_np():
         yield animate(5, result)
         yield animate(5, lines[1].split()[2])
 
-@status_func
+@register_if_installed("acpi")
 def battery():
     try:
         status_output = Popen(["acpi"], stdout=PIPE).communicate()[0]

utils.py

@@ -1,6 +1,7 @@
 # coding: utf-8
 # The dwmstatusline utility module.
 # Written by Timo Paulssen
+from subprocess import Popen, call
 
 def pretty_progressbar(fraction, charsize):
     """Generate a progressbar with accompanying percentage value.
@@ -24,3 +25,27 @@ def pretty_progressbar(fraction, charsize):
       "O",
       " " * bar2size,
       fraction * 100)
+
+_statuses = []
+_transitions = []
+
+# A decorator to add a function to our statuses list.
+def status_func(func):
+    global _statuses
+    _statuses.append(func)
+    return func
+
+def register_if_installed(func, command):
+    if call(["which", command]) == 0:
+        func = transition_func(func)
+    return func
+
+# A decorator to add a function to our transitions list.
+def transition_func(func):
+    global _transitions
+    _transitions.append(func)
+    return func
+
+# This function allows us to set the text of the status line.
+def dwm_set_status(text):
+    Popen(["xsetroot", "-name", text])