# Copyright 2017 SrMouraSilva
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
from abc import ABCMeta, abstractmethod
from unittest.mock import MagicMock
class ParamError(Exception):
def __init__(self, message):
super(ParamError, self).__init__(message)
self.message = message
[docs]class Param(metaclass=ABCMeta):
"""
:class:`Param` represents an Audio Plugin Parameter::
>>> my_awesome_effect
<Lv2Effect object as 'Calf Reverb' active at 0x7fd58d874ba8>
>>> my_awesome_effect.params
(<Lv2Param object as value=1.5 [0.4000000059604645 - 15.0] at 0x7fd587f77908>, <Lv2Param object as value=5000.0 [2000.0 - 20000.0] at 0x7fd587f7a9e8>, <Lv2Param object as value=2 [0 - 5] at 0x7fd587f7cac8>, <Lv2Param object as value=0.5 [0.0 - 1.0] at 0x7fd587f7eba8>, <Lv2Param object as value=0.25 [0.0 - 2.0] at 0x7fd58c576c88>, <Lv2Param object as value=1.0 [0.0 - 2.0] at 0x7fd58c578d68>, <Lv2Param object as value=0.0 [0.0 - 500.0] at 0x7fd58c57ae80>, <Lv2Param object as value=300.0 [20.0 - 20000.0] at 0x7fd58c57df98>, <Lv2Param object as value=5000.0 [20.0 - 20000.0] at 0x7fd58c5810f0>)
>>> param = my_awesome_effect.params[0]
>>> param
<Lv2Param object as value=1.5 [0.4000000059604645 - 15.0] at 0x7fd587f77908>
>>> param.default
1.5
>>> param.value = 14
>>> symbol = param.symbol
>>> symbol
'decay_time'
>>> param == my_awesome_effect.params[symbol]
True
:param Effect effect: Effect in which this parameter belongs
:param default: Default value (initial value parameter)
"""
def __init__(self, effect, default):
self._effect = effect
self._value = default
self._default = default
self.observer = MagicMock()
@property
def effect(self):
"""
:return: Effect in which this parameter belongs
"""
return self._effect
@property
def default(self):
"""
Default parameter value.
Then a effect is instanced, the value initial for a parameter is
your default value.
:getter: Default parameter value.
"""
return self._default
@property
def value(self):
"""
Parameter value
:getter: Current value
:setter: Set the current value
"""
return self._value
@value.setter
def value(self, new_value):
if self._value == new_value:
return
if not(self.minimum <= new_value <= self.maximum):
msg = 'New value out of range: {} [{} - {}]'.format(
new_value,
self.minimum,
self.maximum
)
raise ParamError(msg)
self._value = new_value
self.observer.on_param_value_changed(self)
@property
@abstractmethod
def minimum(self):
"""
:return: Smaller value that the parameter can assume
"""
pass
@property
@abstractmethod
def maximum(self):
"""
:return: Greater value that the parameter can assume
"""
pass
@property
@abstractmethod
def symbol(self):
"""
:return: Param identifier
"""
pass
def __repr__(self, *args, **kwargs):
return "<{} object as value={} [{} - {}] at 0x{:x}>".format(
self.__class__.__name__,
self.value,
self.minimum,
self.maximum,
id(self)
)
@property
def json(self):
"""
Get a json decodable representation of this param
:return dict: json representation
"""
return self.__dict__
@property
def __dict__(self):
return {
'index': self.index,
'minimum': self.minimum,
'maximum': self.maximum,
'symbol': self.symbol,
'value': self.value,
}
@property
def index(self):
return self.effect.params.index(self)