from Tkinter import *

# These are variables I will define as instance variables
#xLoc  - Where is the ball? (X)
#yLoc  - Where is the ball? (Y)
#xVelocity  -  How fast is the ball moving (X)
#yVelocity  -  How fast is the bal moving (Y)
#color - Color of the ball
class Ball:

    # These are class variables, one copy of these variables are stored among all instances
    # of this class
    bouncyness = 0.9

    def __init__(self, xLoc, yLoc, xVelocity, yVelocity):
        self.xLoc = xLoc
        self.yLoc = yLoc
        self.xVelocity = xVelocity
        self.yVelocity = yVelocity


    # Draw the initial ball
    def draw(self, canvas):
        rad = 5
        x1 = self.xLoc-rad
        y1 = self.yLoc-rad
        x2 = self.xLoc+rad
        y2 = self.yLoc+rad
        self.itm = canvas.create_oval(x1, y1, x2, y2, fill='green')
        print "%d %d %d %d " %(x1, y1, x2, y2)
        self.canvas = canvas


    # Update to the new location of the ball
    def update(self):
        mod = 5

        # The ball isn't bouncing... stop!
        if abs(self.yVelocity) < 2 and self.yLoc >= 400:
            self.yVelocity = 0
            self.xVelocity = 0
            return
        else:
            self.yVelocity += 9.8/5

        # Bounce off the "floor"
        if self.yLoc > 400:
            self.direction *= -1
            self.yVelocity = self.yVelocity * self.bouncyness


        deltaY = int(self.yVelocity*self.direction)
        self.yLoc += deltaY

        # Bounce off the "wall"
        if self.xLoc > 400 or self.xLoc < 0:
            self.xVelocity *= -1

        deltaX = self.xVelocity/5
        self.xLoc += deltaX

        self.canvas.move(self.itm, deltaX, deltaY)



# ------------------------------------
# Outside the class
# ------------------------------------
def moveIt():
    ball.update()
    canvas.after(20, moveIt)

def main():
    global ball, canvas

    root = Tk()

    canvas = Canvas(root, width=800, height=800)
    canvas.pack()

    ball = Ball(30, 30, 10, 30)
    ball.draw(canvas)

    canvas.after(1000, moveIt)
    root.mainloop()

main()