61. # File name: ammo.py
62. from kivy.animation import Animation
63. from kivy.uix.image import Image
64. from boom import Boom
65. 
66. class Ammo(Image):
67.   def shoot(self, tx, ty, target):
68.     self.target = target
69.     self.animation = Animation(x=tx, top=ty)
70.     self.animation.bind(on_start = self.on_start)
71.     self.animation.bind(on_progress = self.on_progress)
72.     self.animation.bind(on_complete = self.on_stop)
73.     self.animation.start(self)
74. 
75.   def on_start(self, instance, value):
76.     self.boom = Boom()
77.     self.boom.center=self.center
78.     self.parent.add_widget(self.boom)
79. 
80.   def on_progress(self, instance, value, progression):
81.     if progression >= .1:
82...