# ###########################################################################
#
# This file is part of Taurus
#
# http://taurus-scada.org
#
# Copyright 2011 CELLS / ALBA Synchrotron, Bellaterra, Spain
#
# Taurus is free software: you can redistribute it and/or modify
# it under the terms of the GNU Lesser General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# Taurus is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public License
# along with Taurus. If not, see <http://www.gnu.org/licenses/>.
#
# ###########################################################################
import re
from taurus.external.qt import Qt
from taurus.core.units import Quantity
from pint import DimensionalityError
[docs]class PintValidator(Qt.QValidator):
"""A QValidator for pint Quantities"""
_top = None
_bottom = None
_implicit_units = None
@property
def top(self):
"""
:return: maximum accepted or None if it is not enforced
:rtype: Quantity or None
"""
return self._top
[docs] def setTop(self, top):
"""
Set maximum limit
:param top: maximum acceptable value or None if it is not to be
enforced
:type top: Quantity or None
"""
self._top = Quantity(top)
@property
def units(self):
"""
:return: base units or None if it should not be enforced
:rtype: pint.Unit or None
"""
return self._implicit_units
[docs] def setUnits(self, units):
"""Set implicit units. They will be assumed when the text does not
explicit the unit. They will also be used for dimensionality coherence
checks.
:param units: The implicit unit. If None, implicit dimension is
"unitless" and no dimensionality checks will be performed (other
than those inherent to range enforcement)
:type units: pint.Unit or None
"""
self._implicit_units = units
@property
def bottom(self):
"""
:return: minimum accepted or None if it is not enforced
:rtype: Quantity or None
"""
return self._bottom
[docs] def setBottom(self, bottom):
"""
Set minimum limit
:param bottom: minimum acceptable value or None if it is not to be
enforced
:type bottom: Quantity or None
"""
self._bottom = Quantity(bottom)
[docs] def validate(self, input, pos):
"""Reimplemented from :class:`QValidator` to validate if the input
string is a representation of a quantity within the set bottom and top
limits
"""
# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
# workaround for
# https://github.com/hgrecco/pint/issues/614
# see it also in TaurusLineEdit.getValue()
if re.match(r"^[\+\-]?\s*0+[1-9]+[^.]*$", input.strip()):
return Qt.QValidator.Intermediate, input, pos
# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
try:
q = Quantity(input)
except Exception:
return Qt.QValidator.Intermediate, input, pos
if self._implicit_units is not None:
if q.unitless:
# "cast" to implicit units
q = Quantity(q.magnitude, self.units)
# check coherence with implicit units
elif self._implicit_units.dimensionality != q.dimensionality:
return Qt.QValidator.Intermediate, input, pos
try:
if self.bottom is not None and q < self.bottom:
return Qt.QValidator.Intermediate, input, pos
if self.top is not None and q > self.top:
return Qt.QValidator.Intermediate, input, pos
except DimensionalityError:
return Qt.QValidator.Intermediate, input, pos
return Qt.QValidator.Acceptable, input, pos