FilesExpand file tree

 master

/

state.py

Copy path

Blame

More file actions

Blame

More file actions

Latest commit

 

History

History

History

58 lines (46 loc) · 1.83 KB

 master

/

state.py

Copy path

Top

File metadata and controls

• Code
• Blame

58 lines (46 loc) · 1.83 KB

Raw

Copy raw file

Download raw file

Open symbols panel

Edit and raw actions

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

"""Implementation of the state pattern"""

'''http://ginstrom.com/scribbles/2007/10/08/design-patterns-python-style/'''

class State(object):

"""Base state. This is to share functionality"""

def scan(self):

"""Scan the dial to the next station"""

self.pos += 1

if self.pos == len(self.stations):

self.pos = 0

print("Scanning... Station is", self.stations[self.pos], self.name)

class AmState(State):

def __init__(self, radio):

self.radio = radio

self.stations = ["1250", "1380", "1510"]

self.pos = 0

self.name = "AM"

def toggle_amfm(self):

print("Switching to FM")

self.radio.state = self.radio.fmstate

class FmState(State):

def __init__(self, radio):

self.radio = radio

self.stations = ["81.3", "89.1", "103.9"]

self.pos = 0

self.name = "FM"

def toggle_amfm(self):

print("Switching to AM")

self.radio.state = self.radio.amstate

class Radio(object):

"""A radio. It has a scan button, and an AM/FM toggle switch."""

def __init__(self):

"""We have an AM state and an FM state"""

self.amstate = AmState(self)

self.fmstate = FmState(self)

self.state = self.amstate

def toggle_amfm(self):

self.state.toggle_amfm()

def scan(self):

self.state.scan()

# Test our radio out

if __name__ == '__main__':

radio = Radio()

actions = [radio.scan] * 2 + [radio.toggle_amfm] + [radio.scan] * 2

actions = actions * 2

for action in actions:

action()