class Enum(Variable):
"""A variable wrapper for an enumeration, which is a variable that
can assume one value from a set of specified values.
"""
def __init__(self,
default_value=None,
values=(),
iotype=None,
aliases=(),
desc=None,
**metadata):
assumed_default = False
# Allow some variant constructors (no default, no index)
if not values:
if default_value is None:
raise ValueError("Enum must contain at least one value.")
else:
values = default_value
if isinstance(values, (tuple, list)):
default_value = values[0]
else:
if default_value is None:
default_value = values[0]
assumed_default = True
# We need tuples or a list for the index
if not isinstance(values, (tuple, list)):
values = (values, )
if aliases:
if not isinstance(aliases, (tuple, list)):
aliases = (aliases, )
if len(aliases) != len(values):
raise ValueError("Length of aliases does not match " + \
"length of values.")
if default_value not in values:
raise ValueError("Default value not in values.")
self._validator = TraitEnum(default_value, values, **metadata)
# Put iotype in the metadata dictionary
if iotype is not None:
metadata['iotype'] = iotype
# Put desc in the metadata dictionary
if desc is not None:
metadata['desc'] = desc
# Put values in the metadata dictionary
if values:
metadata['values'] = values
# We also need to store the values in a dict, to get around
# a weak typechecking (i.e., enum of [1,2,3] can be 1.0)
self.valuedict = {}
for val in values:
self.valuedict[val] = val
# Put aliases in the metadata dictionary
if aliases:
metadata['aliases'] = aliases
super(Enum, self).__init__(default_value=default_value,
assumed_default=assumed_default,
**metadata)
def get_attribute(self, name, value, trait, meta):
"""Return the attribute dictionary for this variable. This dict is
used by the GUI to populate the edit UI.
name: str
Name of variable
value: object
The value of the variable
trait: CTrait
The variable's trait
meta: dict
Dictionary of metadata for this variable
"""
attr = {}
attr['name'] = name
attr['type'] = "enum"
attr['value'] = value
for field in meta:
if field not in gui_excludes:
attr[field] = meta[field]
attr['value_types'] = [type(val).__name__ for val in meta['values']]
return attr, None
def validate(self, obj, name, value):
""" Validates that a specified value is valid for this trait."""
try:
val = self._validator.validate(obj, name, value)
except Exception:
self.error(obj, name, value)
# if someone uses a float to set an int-valued Enum, we want it to
# be an int. Enthought's Enum allows a float value, unfortunately.
return self.valuedict[val]
def error(self, obj, name, value):
"""Returns a general error string for Enum."""
# pylint: disable-msg=E1101
vtype = type(value)
if value not in self.values:
info = str(self.values)
msg = "Variable '%s' must be in %s, " % (name, info) + \
"but a value of %s %s was specified." % (value, vtype)
else:
msg = "Unknown error while setting trait '%s';" % (name) +\
"a value of %s %s was specified." % (value, vtype)
try:
obj.raise_exception(msg, ValueError)
except AttributeError:
raise ValueError(msg)
class Enum(Variable):
"""A variable wrapper for an enumeration, which is a variable that
can assume one value from a set of specified values.
"""
def __init__(self, default_value=None, values=(), iotype=None,
aliases=(), desc=None, **metadata):
assumed_default = False
# Allow some variant constructors (no default, no index)
if not values:
if default_value is None:
raise ValueError("Enum must contain at least one value.")
else:
values = default_value
if isinstance(values, (tuple, list)):
default_value = values[0]
else:
if default_value is None:
default_value = values[0]
assumed_default = True
# We need tuples or a list for the index
if not isinstance(values, (tuple, list)):
values = (values,)
if aliases:
if not isinstance(aliases, (tuple, list)):
aliases = (aliases,)
if len(aliases) != len(values):
raise ValueError("Length of aliases does not match "
"length of values.")
if default_value not in values:
raise ValueError("Default value not in values.")
self._validator = TraitEnum(default_value, values, **metadata)
# Put iotype in the metadata dictionary
if iotype is not None:
metadata['iotype'] = iotype
# Put desc in the metadata dictionary
if desc is not None:
metadata['desc'] = desc
# Put values in the metadata dictionary
if values:
metadata['values'] = values
# We also need to store the values in a dict, to get around
# a weak typechecking (i.e., enum of [1,2,3] can be 1.0)
self.valuedict = {}
for val in values:
self.valuedict[val] = val
# Put aliases in the metadata dictionary
if aliases:
metadata['aliases'] = aliases
if 'assumed_default' in metadata:
del metadata['assumed_default']
super(Enum, self).__init__(default_value=default_value,
assumed_default=assumed_default, **metadata)
def get_attribute(self, name, value, trait, meta):
"""Return the attribute dictionary for this variable. This dict is
used by the GUI to populate the edit UI.
name: str
Name of variable
value: object
The value of the variable
trait: CTrait
The variable's trait
meta: dict
Dictionary of metadata for this variable
"""
attr = {}
attr['name'] = name
attr['type'] = "enum"
attr['value'] = value
for field in meta:
if field not in gui_excludes:
attr[field] = meta[field]
attr['value_types'] = [type(val).__name__ for val in meta['values']]
return attr, None
def validate(self, obj, name, value):
""" Validates that a specified value is valid for this trait."""
try:
val = self._validator.validate(obj, name, value)
except Exception:
self.error(obj, name, value)
# if someone uses a float to set an int-valued Enum, we want it to
# be an int. Enthought's Enum allows a float value, unfortunately.
return self.valuedict[val]
def error(self, obj, name, value):
"""Returns a general error string for Enum."""
# pylint: disable=E1101
vtype = type(value)
if value not in self.values:
info = str(self.values)
msg = "Variable '%s' must be in %s, " % (name, info) + \
"but a value of %s %s was specified." % (value, vtype)
else:
msg = "Unknown error while setting trait '%s';" % (name) +\
"a value of %s %s was specified." % (value, vtype)
try:
obj.raise_exception(msg, ValueError)
except AttributeError:
raise ValueError(msg)
