Source Code for Script script-demo_FunctionCyclePlan_py

 1  from joy import * 
 2  from math import sin,pi 
 3   
 4 -class FunctionCyclePlanApp( JoyApp ): 
 5 -  def __init__(self,*arg,**kw): 
 6      JoyApp.__init__(self,*arg,**kw) 
 7       
 8 -  def onStart( self ): 
 9      def fun( phase ): 
10        s = sin(phase*2*pi) 
11        progress( " "*(int((s+1)*30)) + "#" )    
12      self.plan = FunctionCyclePlan(self, fun, 24) 
13      self.plan.onStart = curry(progress,">>> START") 
14      self.plan.onStop = curry(progress,">>> STOP") 
15      self.freq = 1.0 
16      self.rate = 0.05 
17      self.limit = 1/0.45 
18         
19 -  def onEvent(self, evt): 
20      if evt.type==KEYDOWN: 
21        if evt.key in [ord('q'),27]: # 'q' and [esc] stop program 
22          self.stop() 
23          # 
24        elif evt.key==ord(' '): # [space] stops cycles 
25          self.plan.setPeriod(0) 
26          progress('Period changed to %s' % str(self.plan.period)) 
27          # 
28        elif evt.key in (ord(','),ord('.')): 
29          f = self.freq 
30          # Change frequency up/down in range -limit..limit hz 
31          if evt.key==ord(','): 
32            f = (1-self.rate)*f - self.rate*self.limit 
33          else: 
34            f = (1-self.rate)*f + self.rate*self.limit 
35          if abs(f) < 1.0/self.limit: 
36            self.plan.setPeriod( 0 ) 
37          else: 
38            self.plan.setPeriod( 1/f ) 
39          self.freq = f 
40          progress('Period changed to %g, %.2f Hz' % (self.plan.period,f)) 
41          # 
42        elif evt.key==ord('h'): 
43          progress( "HELP: ',' to decrease/reverse period; '.' opposite; ' ' stop; 'q' end program; 'h' this help; other keys start Plan" ) 
44          # 
45        else: # any other key 
46          progress( "Starting cycles...." ) 
47          self.plan.start() 
48      if evt.type!=TIMEREVENT: 
49        JoyApp.onEvent(self,evt) 
50         
51  if __name__=="__main__": 
52    print """ 
53    Demo of FunctionCyclePlan class 
54    ------------------------------- 
55     
56    When any key is pressed, starts a FunctionCyclePlan that prints 
57    an ASCII art sine wave under keyboard control. 
58   
59    h -- help 
60    q -- quit 
61    , and . -- change rate 
62    SPACE -- pause / resume 
63    any other key -- start  
64     
65    The application can be terminated with 'q' or [esc] 
66    """ 
67    import joy 
68    joy.DEBUG[:]=[] 
69    app=FunctionCyclePlanApp() 
70    app.run() 
71