[modules/nic] Re-enable NIC module

Re-add the NIC module with all its functionality (hopefully...).

This introduces a new concept: Instead of having separate queries for
critical and warning (which really are just another set of states), a
module can now return a list of states for each widget. All the state
information is then merged together into a single theme. So, for
instance, the NIC module can return a state saying "critical -
wlan-down", which applies the theme information for both "critical" and
"wlan-down".

see #23

bumblebee/modules/cmus.py

@@ -80,3 +80,5 @@ class Module(bumblebee.engine.Module):
                 self._repeat = False if "false" in line else True
             if line.startswith("set shuffle "):
                 self._shuffle = False if "false" in line else True
+
+# vim: tabstop=8 expandtab shiftwidth=4 softtabstop=4

bumblebee/modules/nic.py

@@ -0,0 +1,67 @@
+#pylint: disable=C0111,R0903
+
+import netifaces
+
+import bumblebee.util
+import bumblebee.input
+import bumblebee.output
+import bumblebee.engine
+
+"""Displays the name, IP address(es) and status of each available network interface."""
+
+class Module(bumblebee.engine.Module):
+    def __init__(self, engine, config):
+        widgets = []
+        super(Module, self).__init__(engine, config, widgets)
+        self._exclude = tuple(filter(len, self.parameter("exclude", "lo,virbr,docker,vboxnet,veth").split(",")))
+        self._update_widgets(widgets)
+
+    def update(self, widgets):
+        self._update_widgets(widgets)
+
+    def state(self, widget):
+        states = []
+
+        if widget.get("state") == "down":
+            states.append("critical")
+        elif widget.get("state") != "up":
+            states.append("warning")
+
+        intf = widget.get("intf")
+        iftype = "wireless" if self._iswlan(intf) else "wired"
+        iftype = "tunnel" if self._istunnel(intf) else iftype
+
+        states.append("{}-{}".format(iftype, widget.get("state")))
+
+        return states
+
+    def _iswlan(self, intf):
+        # wifi, wlan, wlp, seems to work for me
+        if intf.startswith("w"): return True
+        return False
+
+    def _istunnel(self, intf):
+        return intf.startswith("tun")
+
+    def _update_widgets(self, widgets):
+        interfaces = [ i for i in netifaces.interfaces() if not i.startswith(self._exclude) ]
+        for intf in interfaces:
+            addr = []
+            state = "down"
+            try:
+                if netifaces.AF_INET in netifaces.ifaddresses(intf):
+                    for ip in netifaces.ifaddresses(intf)[netifaces.AF_INET]:
+                        if "addr" in ip and ip["addr"] != "":
+                            addr.append(ip["addr"])
+                            state = "up"
+            except Exception as e:
+                addr = []
+            widget = self.widget(intf)
+            if not widget:
+                widget = bumblebee.output.Widget(name=intf)
+                widgets.append(widget)
+            widget.full_text("{} {} {}".format(intf, state, ", ".join(addr)))
+            widget.set("intf", intf)
+            widget.set("state", state)
+
+# vim: tabstop=8 expandtab shiftwidth=4 softtabstop=4