CSC111 Moving Graphic Objects

--D. Thiebaut (talk) 09:48, 20 April 2014 (EDT)

---

Note: Depending on the installation of your Python and Tkinter program (that Python uses to perform graphics), the code below may or may not work. On some installation of Tkinter, the code shows animation and objects moving, on some other computers the moving of items does not show up.

A car that moves out of the canvas

The example program below requires the graphics library available on this page.

# carMovesRight.py
# D. Thiebaut
# Demonstrates the user the graphics111 library with
# moveable objects, menu, and event-driven programming
# This program creates a car, and then moves it to the right
# by the amount in deltaX until the car disappears from the 
# canvas.

from graphics111 import *
from random import seed
from random import randrange
from time   import sleep

MAXWIDTH = 800
MAXHEIGHT = 600

         
class Car:
    def __init__( self, x, y, width, height, color ):
        self._x       = x 
        self._y       = y 
        self._width   = width
        self._height  = height
        self._color   = color   # list of 3 ints between 0 and 255

        # build the body
        self._top  = Rectangle( x+width//4, y-height//2,
                                width//2, height//2,
                                color )
        self._body = Rectangle( x, y, width, height, color )
        
        # build the wheels
        self._w1 = Wheel( x + width//4, y + height, width//5 )
        self._w2 = Wheel( x + 3*width//4, y + height, width//5 )

    def setRandomColor( self ):
        self._top.setRandomColor()
        self._body.setRandomColor()
        
    def getTotalHeight( self ):
        return self._height*2 +  self._width//10

    def getTotalWidth( self ):
        return self._width
        
    def draw( self, canvas ):
        self._canvas = canvas
        self._body.draw( canvas )
        self._top.draw( canvas )
        self._w1.draw( canvas )
        self._w2.draw( canvas )

    def move( self, canvas, dx, dy ):
        self._body.move( canvas, dx, dy )
        self._top.move( canvas, dx, dy )
        self._w1.move( canvas, dx, dy )
        self._w2.move( canvas, dx, dy )
        


# ========================================================
#                       Main Program
# ========================================================
def main():
    # make the menu and car global so that they will
    # be accessible to the call-back function
    global menu, car

    # open the window and get access to its canvas
    win = GraphicsWindow(MAXWIDTH, MAXHEIGHT)
    canvas = win.canvas()
        
    # draw something
    p1 = Polygon( (100, 100, 150, 50, 350, 50, 400, 100), (255, 0, 0 ) )
    p1.draw( canvas )

    car = Car( 150, 75, 100, 20, (250, 250, 0 ) )
    car.draw( canvas )

    deltaX = 5
    for i in range( MAXWIDTH//deltaX ):
        car.move( canvas, deltaX, 0 )
        
    # wait and respond to events, or comment out and make the program
    # stop as soon as car disappears.
    win.wait()
    win.close()
    
main()