CSC111 newCarLab10.py

--D. Thiebaut 13:46, 14 April 2010 (UTC)

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# newCarLab10.py
# D. Thiebaut
# Another example of inheritance

from carLab10 import *
from graphics import * 


class NewCar( Car ):
    
    def __init__( self, P1, P2, dx, label="1" ):
        Car.__init__( self, P1, P2, dx )
        xc = (P1.getX() + P2.getX())/2
        yc = (P1.getY() + P2.getY())/2
        d = min( abs( P1.getX()-P2.getX() ),
                 abs( P1.getY()-P2.getY() ) )
        self.labelCircle = Circle( Point( xc, yc ), d/2 )
        self.label = Text( Point( xc, yc ), label )
        Car.setFill( self, "red", "black", "grey" )
        self.moveCount = 10

    def draw( self, win ):
        Car.draw( self, win )
        self.labelCircle.draw( win )
        self.label.draw( win )

    def move( self, dx, dy ):
        Car.move( self, dx, dy )
        self.label.move( self.dx, dy )
        self.labelCircle.move( self.dx, dy )
        self.moveCount += 1
        if self.moveCount % 10 == 0:
            self.dx = -self.dx

def waitForClick( win, message ):
    """ waitForClick: stops the GUI and displays a message.                                                           
    Returns when the user clicks the window. The message is erased."""

    # wait for user to click mouse to start
    startMsg = Text( Point( win.getWidth()/2, win.getHeight()/2 ), message )
    startMsg.draw( win )    # display message                                                
    win.getMouse()          # wait                                                             
    startMsg.undraw()       # erase                                                      

def main():
    """displays the graphics window and an instance of myRect"""
    win = GraphWin( "Inheritance", 400, 400 )
    c = NewCar( Point( 20,120 ), Point( 150, 150 ), 3, "10" )
    c.draw( win )

    waitForClick( win, "Click to move" )
    for i in range( 100 ):
        c.move( 3, 0 )

    waitForClick( win, "Click to quit" )

main()