[modules] Add date, time, datetime

Add modules to show date, time and date and time. Instead of introducing
a "fancy" aliasing mechanism, simply implement time and date in terms of
datetime, by inheriting and overwriting selectively.

modules/date.py

@@ -0,0 +1,19 @@
+# pylint: disable=C0111,R0903
+
+'''Displays the current date and time.
+
+Parameters:
+    * date.format: strftime()-compatible formatting string
+    * date.locale: locale to use rather than the system default
+'''
+
+from .datetime import Module
+
+class Module(Module):
+    def __init__(self, config):
+        super().__init__(config)
+
+    def default_format(self):
+        return '%x'
+
+# vim: tabstop=8 expandtab shiftwidth=4 softtabstop=4

modules/datetime.py

@@ -0,0 +1,43 @@
+# pylint: disable=C0111,R0903
+
+'''Displays the current date and time.
+
+Parameters:
+    * datetime.format: strftime()-compatible formatting string
+    * datetime.locale: locale to use rather than the system default
+'''
+
+from __future__ import absolute_import
+import datetime
+import locale
+
+import core.module
+import core.widget
+
+class Module(core.module.Module):
+    def __init__(self, config):
+        super().__init__(config, core.widget.Widget(self.full_text))
+        # TODO: register callback
+        #engine.input.register_callback(self, button=bumblebee.input.LEFT_MOUSE,
+        #                            cmd='calendar')
+        self._fmt = self.parameter('format', self.default_format())
+        l = locale.getdefaultlocale()
+        if not l or l == (None, None):
+            l = ('en_US', 'UTF-8')
+        lcl = self.parameter('locale', '.'.join(l))
+        try:
+            locale.setlocale(locale.LC_TIME, lcl.split('.'))
+        except Exception as e:
+            locale.setlocale(locale.LC_TIME, ('en_US', 'UTF-8'))
+
+    def default_format(self):
+        return '%x %X'
+
+    def full_text(self):
+        enc = locale.getpreferredencoding()
+        retval = datetime.datetime.now().strftime(self._fmt)
+        if hasattr(retval, 'decode'):
+            return retval.decode(enc)
+        return retval
+
+# vim: tabstop=8 expandtab shiftwidth=4 softtabstop=4

modules/time.py

@@ -0,0 +1,19 @@
+# pylint: disable=C0111,R0903
+
+'''Displays the current date and time.
+
+Parameters:
+    * time.format: strftime()-compatible formatting string
+    * time.locale: locale to use rather than the system default
+'''
+
+from .datetime import Module
+
+class Module(Module):
+    def __init__(self, config):
+        super().__init__(config)
+
+    def default_format(self):
+        return '%X'
+
+# vim: tabstop=8 expandtab shiftwidth=4 softtabstop=4