[modules] Add CPU module

Also, change minwidth from theme.minwidth to widget property

modules/core/cpu.py

@@ -0,0 +1,38 @@
+# pylint: disable=C0111,R0903
+
+'''Displays CPU utilization across all CPUs.
+
+Parameters:
+    * cpu.warning : Warning threshold in % of CPU usage (defaults to 70%)
+    * cpu.critical: Critical threshold in % of CPU usage (defaults to 80%)
+    * cpu.format  : Format string (defaults to '{:.01f}%')
+'''
+
+import psutil
+
+import core.module
+import core.widget
+import core.input
+
+class Module(core.module.Module):
+    def __init__(self, config=None):
+        super().__init__(config, core.widget.Widget(self.utilization))
+        self.widget().minwidth = self._format.format(100.0-10e-20)
+        self._utilization = psutil.cpu_percent(percpu=False)
+        core.input.register(self, button=core.input.LEFT_MOUSE,
+            cmd='gnome-system-monitor')
+
+    @property
+    def _format(self):
+        return self.parameter('format', '{:.01f}%')
+
+    def utilization(self, _):
+        return self._format.format(self._utilization)
+
+    def update(self):
+        self._utilization = psutil.cpu_percent(percpu=False)
+
+    def state(self, _):
+        return self.threshold_state(self._utilization, 70, 80)
+
+# vim: tabstop=8 expandtab shiftwidth=4 softtabstop=4