# Chapter Graphics/wheel0.py
"""ONE wheel moving on the canvas stops when reach border
"""
from graphics import *
winW, winH = 400, 200    # window geometry
class Wheel: # 2 concentric circles: big circle & small circle
    def __init__( self, c, rs, rb ): # constructor: c= center,rs = small radius, rb=big radius
        self.bCircle = Circle( c, rb )
        self.sCircle = Circle( c, rs )
         
    def move( self, dx, dy ):
        self.bCircle.move( dx, dy )
        self.sCircle.move( dx, dy )
        
    def setFill( self, colors, colorb ):
        self.bCircle.setFill( colorb )
        self.sCircle.setFill( colors )
        
    def ddraw( self, win ):
         self.bCircle.draw( win )
         self.sCircle.draw( win )

    def getCenter( self ):
        return self.bCircle.getCenter()

    def getRadius( self ):
        return self.bCircle.getRadius()

def main():
    win = GraphWin( "Demo: Wheels moving", winW, winH  )
    w1 = Wheel( Point( 50, 30 ), 10, 20 )
    w1.setFill( "black", "yellow" )
    w1.ddraw( win )
    while True:
        w1.move( 0.1, 0 )
        if w1.getCenter().getX() > winW - w1.getRadius():
            break 
 
main()