#------------------------------------------------------------------------------
# Copyright (c) 2011, Enthought, Inc.
# All rights reserved.
#------------------------------------------------------------------------------
from datetime import datetime as py_datetime
from dateutil.parser import parse as parse_iso_dt
from traits.api import Property, BaseInstance, on_trait_change
from enaml.core.trait_types import Bounded
from .control import Control
#: A custom trait which validates Python datetime instances.
Datetime = BaseInstance(py_datetime)
[docs]class BoundedDatetime(Control):
""" A base class for use with widgets that edit a Python
datetime.datetime object bounded between minimum and maximum
values. This class is not meant to be used directly.
"""
#: The minimum datetime available in the datetime edit. If not
#: defined then the default value is midnight September 14, 1752.
minimum = Property(Datetime, depends_on ='_minimum')
#: The internal minimum datetime storage
_minimum = Datetime(py_datetime(1752, 9, 14, 0, 0, 0, 0))
#: The maximum datetime available in the datetime edit. If not
#: defined then the default value is the second before midnight
#: December 31, 7999.
maximum = Property(Datetime, depends_on ='_maximum')
#: The internal maximum datetime storage
_maximum = Datetime(py_datetime(7999, 12, 31, 23, 59, 59, 999000))
#: The currently selected date. Default is datetime.now(). The
#: value is bounded between :attr:`minimum` and :attr:`maximum`.
datetime = Bounded(Datetime(py_datetime.now()), low='minimum', high='maximum')
#--------------------------------------------------------------------------
# Initialization
#--------------------------------------------------------------------------
[docs] def snapshot(self):
""" Return a dictionary which contains all the state necessary to
initialize a client widget.
"""
snap = super(BoundedDatetime, self).snapshot()
snap['minimum'] = self.minimum.isoformat()
snap['maximum'] = self.maximum.isoformat()
snap['datetime'] = self.datetime.isoformat()
return snap
[docs] def bind(self):
""" A method called after initialization which allows the widget
to bind any event handlers necessary.
"""
super(BoundedDatetime, self).bind()
otc = self.on_trait_change
otc(self._send_minimum, 'minimum')
otc(self._send_maximum, 'maximum')
otc(self._send_datetime, 'datetime')
#--------------------------------------------------------------------------
# Message Handling
#--------------------------------------------------------------------------
[docs] def on_action_datetime_changed(self, content):
""" The handler for the 'datetime_changed' action sent from the
client widget.
"""
datetime = parse_iso_dt(content['datetime'])
self.set_guarded(datetime=datetime)
def _send_minimum(self):
""" Send the minimum datetime to the client widget.
"""
content = {'minimum': self.minimum.isoformat()}
self.send_action('set_minimum', content)
def _send_maximum(self):
""" Send the maximum datetime to the client widget.
"""
content = {'maximum': self.maximum.isoformat()}
self.send_action('set_maximum', content)
def _send_datetime(self):
""" Send the current datetime to the client widget.
"""
if 'datetime' not in self.loopback_guard:
content = {'datetime': self.datetime.isoformat()}
self.send_action('set_datetime', content)
#--------------------------------------------------------------------------
# Properties
#--------------------------------------------------------------------------
def _get_minimum(self):
""" The property getter for the minimum datetime.
"""
return self._minimum
def _set_minimum(self, datetime):
""" The property setter for the minimum datetime.
If the new minimum is greater than the current maximum, then the
maximum will be adjusted up.
"""
if datetime > self._maximum:
self._maximum = datetime
self._minimum = datetime
def _get_maximum(self):
""" The property getter for the maximum datetime.
"""
return self._maximum
def _set_maximum(self, datetime):
""" The property setter for the maximum datetime.
If the new maximum is less than the current minimum, then the
minimum will be ajusted down.
"""
if datetime < self._minimum:
self._minimum = datetime
self._maximum = datetime
#--------------------------------------------------------------------------
# Private API
#--------------------------------------------------------------------------
@on_trait_change('minimum, maximum')
def _adapt_datetime(self):
""" Actively adapt the datetime to lie within the boundaries.
"""
self.datetime = min(max(self.datetime, self.minimum), self.maximum)