#ChapterOO/Balloon0.py 
from graphics import *
winW, winH = 500, 500    # window geometry
class Balloon:
    def __init__( self, c, r ):    # constructor: c = center point, radius
        self.bCircle = Circle( c, r )
        
    def move( self, dx, dy ):
       self.bCircle.move( dx, dy )
                
    def ddraw( self, win ):
         self.bCircle.draw( win )
   
def main():
    win = GraphWin( "Demo0: 3 Balloons", winW, winH  )
    b1 = Balloon( Point(50,30), 20 )  
    b2 = Balloon(Point(170,100),30)
    b3 = Balloon(Point(250,200),35)
    blist=[b1,b2,b3]
    for b in blist: #draw objects
        b.bCircle.setFill("red")
        b.ddraw(win)
    if win.getMouse():  #move objects
        while True:
            b1.move( 0.1, 0 )
            b2.move(0,0.1)

main()