PythonPatterns/observer/observer.py at master · brunodmartins/PythonPatterns · GitHub

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
"""
Created on 15/03/2016

@author: bruno.martins
"""

import abc


class TemperatureSubject(object):
    """
    classdocs
    """
    thermometers = []

    def __init__(self):
        self.__temperature = None

    @property
    def temperature(self):
        """Returns the current Celsius temperature"""
        return self.__temperature

    @temperature.setter
    def temperature(self, value):
        """Sets the current temperature in Celsius"""
        self.__temperature = value
        self.notify_thermometers()

    def notify_thermometers(self):
        """Notify all observer"""
        for thermometer in self.thermometers:
            thermometer.update()

    def attach(self, thermometer):
        """attach observer"""
        self.thermometers.append(thermometer)

    def deatach(self, thermometer):
        """detach obsrever"""
        self.thermometers.remove(thermometer)


class Thermometer(object):
    """
    Abstract class to thermometer
    """
    __metaclass__ = abc.ABCMeta

    temperature = 0

    @abc.abstractmethod
    def update(self):
        """updates the temperature in thermometer"""
        raise NotImplementedError


class CelsiusThermometer(Thermometer):
    """
    Celsius thermometer
    """
    temperature_subject = None

    def __init__(self, temperature_subject):
        self.temperature_subject = temperature_subject
        temperature_subject.attach(self)

    def update(self):
        self.temperature = self.temperature_subject.temperature
        print('Celsius:' + str(self.temperature))


class FahrenheitThermometer(Thermometer):
    """
    Fahrenheit thermometer
    """

    temperature_subject = None

    def __init__(self, temperature_subject):
        self.temperature_subject = temperature_subject
        temperature_subject.attach(self)

    def update(self):
        self.temperature = self.temperature_subject.temperature * 1.8000 + 32.00
        print('Fahrenheit:' + str(self.temperature))


class KelvinThermometer(Thermometer):
    """
    Kelvin thermometer
    """
    temperature_subject = None

    def __init__(self, temperature_subject):
        self.temperature_subject = temperature_subject
        temperature_subject.attach(self)

    def update(self):
        self.temperature = self.temperature_subject.temperature + 273.15
        print('Kelvin:' + str(self.temperature))