secsgem/secs/variables/boolean.py
#####################################################################
# boolean.py
#
# (c) Copyright 2021, Benjamin Parzella. All rights reserved.
#
# This library 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 2.1 of the License, or (at your option) any later version.
#
# This software 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.
#####################################################################
"""SECS boolean variable type."""
from .base import Base
class Boolean(Base):
"""Secs type for boolean data."""
format_code = 0o11
text_code = "BOOLEAN"
preferred_types = [bool]
_true_strings = ["TRUE", "YES"]
_false_strings = ["FALSE", "NO"]
def __init__(self, value=None, count=-1):
"""Initialize a boolean secs variable.
:param value: initial value
:type value: list/boolean
:param count: number of items this value
:type count: integer
"""
super().__init__()
self.value = []
self.count = count
if value is not None:
self.set(value)
def __repr__(self):
"""Generate textual representation for an object of this class."""
if len(self.value) == 0:
return f"<{self.text_code}>"
data = " ".join([str(value) for value in self.value])
return f"<{self.text_code} {data} >"
def __len__(self):
"""Get the length."""
return len(self.value)
def __getitem__(self, key):
"""Get an item using the indexer operator."""
return self.value[key]
def __setitem__(self, key, item):
"""Set an item using the indexer operator."""
self.value[key] = item
def __eq__(self, other):
"""Check equality with other object."""
if isinstance(other, Base):
if other.is_dynamic:
return other.value.value == self.value
return other.value == self.value
if isinstance(other, list):
return other == self.value
return [other] == self.value
def __hash__(self):
"""Get data item for hashing."""
return hash(str(self.value))
def _check_single_item_support(self, value):
if isinstance(value, bool):
return True
if isinstance(value, int):
if 0 <= value <= 1:
return True
return False
if isinstance(value, str):
if value.upper() in self._true_strings or value.upper() in self._false_strings:
return True
return False
return False
def supports_value(self, value) -> bool:
"""Check if the current instance supports the provided value.
:param value: value to test
:type value: any
"""
if isinstance(value, (list, tuple)):
return self._supports_value_list(value)
if isinstance(value, bytearray):
return self._supports_value_bytearray(value)
return self._check_single_item_support(value)
def _supports_value_list(self, value) -> bool:
if 0 < self.count < len(value):
return False
return all(self._check_single_item_support(item) for item in value)
def _supports_value_bytearray(self, value) -> bool:
if 0 < self.count < len(value):
return False
return all(0 <= char <= 1 for char in value)
def __convert_single_item(self, value):
if isinstance(value, bool):
return value
if isinstance(value, int):
if not 0 <= value <= 1:
raise ValueError(f"Value {value} out of bounds")
return bool(value)
if isinstance(value, str):
if value.upper() in self._true_strings:
return True
if value.upper() in self._false_strings:
return False
raise ValueError(f"Value {value} out of bounds")
raise ValueError(f"Can't convert value {value}")
def set(self, value):
"""Set the internal value to the provided value.
:param value: new value
:type value: list/boolean
"""
if isinstance(value, (list, tuple)):
if 0 <= self.count < len(value):
raise ValueError(f"Value longer than {self.count} chars")
self.value = [self.__convert_single_item(item) for item in value]
elif isinstance(value, bytearray):
if 0 <= self.count < len(value):
raise ValueError(f"Value longer than {self.count} chars")
new_value = []
for char in value:
if not 0 <= char <= 1:
raise ValueError(f"Value {char} out of bounds")
new_value.append(char)
self.value = new_value
else:
self.value = [self.__convert_single_item(value)]
def get(self):
"""Return the internal value.
:returns: internal value
:rtype: list/boolean
"""
if len(self.value) == 1:
return self.value[0]
return self.value
def encode(self):
"""Encode the value to secs data.
:returns: encoded data bytes
:rtype: string
"""
result = self.encode_item_header(len(self.value))
for value in self.value:
if value:
result += b"\1"
else:
result += b"\0"
return result
def decode(self, data, start=0):
"""Decode the secs byte data to the value.
:param data: encoded data bytes
:type data: string
:param start: start position of value the data
:type start: integer
:returns: new start position
:rtype: integer
"""
(text_pos, _, length) = self.decode_item_header(data, start)
result = []
for _ in range(length):
if bytearray(data)[text_pos] == 0:
result.append(False)
else:
result.append(True)
text_pos += 1
self.set(result)
return text_pos