Source Code for Module MeatEngine.Logic.fsmMgr

 1  """Meat Engine Hierarchical Finite State Machine (hFSM) Manager 
 2   
 3  This could be refactored so that a fsmMgr is an instatiatable class, 
 4  but for now it uses the "lazy singleton" pattern - the state stack is 
 5  a module global, and methods are just module functions. This is 
 6  adequate for my needs so far. 
 7   
 8  Use: create State objects, push them on the stack. Periodically call 
 9  the update and draw functions, and pass the handleKey and 
10  handleMouseButton events in as appropriate. The top state will get 
11  delegated to, which may choose to delegate further. For example, a 
12  dialog box may choose to call the next state's draw code first, before 
13  drawing itself. 
14  """ 
15   
16   
17 -class State: 
18 -    def __init__(self): 
19          self.parent=None 
20   
21 -    def handleMouseButton(self, bDown, buttonIndex): 
22          return False 
23   
24 -    def handleKey(self, key, unicode): 
25          return False 
26   
27 -    def init(self): 
28          pass 
29   
30 -    def activateApp(self, bNowActive): 
31          return False 
32   
33           
34   
35  gStateStack=[] 
36   
37 -def pushState(newState): 
38      try: 
39          oldTop=gStateStack[-1] 
40      except: 
41          oldTop=None 
42   
43      gStateStack.append(newState) 
44      newState.parent=oldTop 
45      newState.init() 
46           
47   
48 -def popState(): 
49      gStateStack.pop() 
50       
51   
52 -def popAll(): 
53      global gStateStack 
54      gStateStack=[] 
55   
56   
57 -def handleKey(k, unicode): 
58      for s in reversed(gStateStack): 
59          if s.handleKey(k, unicode): 
60              return True 
61      return False 
62   
63 -def handleActivate(bNowActive): 
64      for s in reversed(gStateStack): 
65          if s.activateApp(bNowActive): 
66              return True 
67      return False 
68   
69 -def handleMouseButton(bDown, button): 
70      for s in reversed(gStateStack): 
71          if s.handleMouseButton(bDown, button): 
72              return True 
73      return False 
74   
75 -def update(ms): 
76      if not len(gStateStack): 
77          return False 
78       
79      gStateStack[-1].update(ms) 
80      return True 
81   
82 -def draw(): 
83      if not len(gStateStack): 
84          return 
85   
86      gStateStack[-1].draw() 
87   
88 -def isTop(state): 
89      return len(gStateStack)>0 and state==gStateStack[-1] 
90