from Tkinter import *

# special numbers that represent the arrow keys
_up_keycode_ = 8320768
_down_keycode_ = 8255233
_left_keycode_ = 8124162
_right_keycode_ = 8189699

class Ball:
	def __init__(self, name, color, centerX, centerY, radius, speed, canvas):
		# The __init__ function is called when you create a ball, such as when you type in
		# x = Ball(name='ball name', color='red', centerX=10, centerY=10, radius=2, speed=5, canvas=canvas) 

		# Determine the bounding box of the ball.  A "bounding box" is the 
		# smallest square you can draw around the circle, and you can describe
		# it using x0, y0, x1, and y1.	The top left corner is as (x0, y0), 
		# the top right corner is at (x1, y0), the bottom right corner is at
		# (x1, y1) and the bottom left corner is at (x0, y1)
		self.x0 = centerX - radius
		self.y0 = centerY - radius
		self.x1 = centerX + radius
		self.y1 = centerY + radius

		# save the speed we want the ball to move in the x and y direction
		self.deltaX = speed
		self.deltaY = speed 

		# hold onto the canvas we're drawing onto for later use
		self.canvas = canvas

		# we need a name for some reason. 
		self.name = name

		# finally, tell the canvas to draw the circle
		self.circle = canvas.create_oval(
			self.x0, 
			self.y0, 
			self.x1, 
			self.y1, 
			fill=color, 
			tag=name)

	def move(self):
		# Move the ball a little bit.

		# check if the ball is still inside the window.	 If it isn't, make it change it's direction
		if self.x1 >= canvas.winfo_width() and self.deltaX > 0:
			self.deltaX = -self.deltaX
		elif self.x0 <= 0 and self.deltaX < 0:
			self.deltaX = -self.deltaX
		if self.y1 >= canvas.winfo_height() and self.deltaY > 0:
			self.deltaY = -self.deltaY
		if self.y0 <= 0 and self.deltaY < 0:
			self.deltaY = -self.deltaY

		# tell the canvas to move the image of the ball over a bit
		self.canvas.move(self.name, self.deltaX, self.deltaY)

		# keep track of where the ball is
		self.x0 += self.deltaX
		self.x1 += self.deltaX
		self.y0 += self.deltaY
		self.y1 += self.deltaY

class Bar:
	def __init__(self, name, color, x0, y0, x1, y1, speed, canvas, window):
		# The __init__ function is called when you create a Bar.

		# this tells the computer to call "keyup" when a button is released
		# and "keydown" when a button is pressed
		window.bind('<KeyRelease>', self.keyup)
		window.bind('<KeyPress>', self.keydown)

		# we remember the speed, but this Bar isn't moving because 
		# self.deltaX and self.deltaY are zero.
		self.speed = speed
		self.deltaX = 0
		self.deltaY = 0

		# save the corner locations for this box
		self.x0 = x0
		self.y0 = y0
		self.x1 = x1
		self.y1 = y1

		# hold onto the canvas we're drawing onto for later use
		self.canvas = canvas

		# we need a name for some reason. 
		self.name = name

		# finally, tell the canvas to draw the rectangle 
		self.rect = canvas.create_rectangle(
			self.x0, 
			self.y0, 
			self.x1, 
			self.y1, 
			fill=color, 
			tag=name)

	def keydown(self, event):
		# This gets called whenever a key is pressed.
		# you can see what letter it is by typing
		# print event.char

		# Here we check if the key that was pressed was any of the up, down,
		# left or right keys. If it was, we change the deltaY or deltaX values
		if event.keycode == _up_keycode_:
			self.deltaY = -self.speed
		elif event.keycode == _down_keycode_:
			self.deltaY = self.speed
		elif event.keycode == _left_keycode_:
			self.deltaX = -self.speed
		elif event.keycode == _right_keycode_:
			self.deltaX = self.speed

	def keyup(self, event):
		# This gets called whenever a key is released.
		# You can see what letter it is by typing
		# print event.char

		# Here we check if the key that was pressed was any of the up, down,
		# left or right keys. If it was, we change the deltaY or deltaX values
		if event.keycode == _up_keycode_ or event.keycode == _down_keycode_:
			self.deltaY = 0
		elif event.keycode == _left_keycode_ or event.keycode == _right_keycode_:
			self.deltaX = 0

	def move(self):
		# this moves the rectangle 
		self._move(self.deltaX, self.deltaY)

	def _move(self, deltaX, deltaY):
		# Move the rectangle a little bit.

		# check if the ball is still inside the window.	 If it isn't, make it change it's direction
		if self.x1 >= canvas.winfo_width() and deltaX > 0:
			deltaX = 0
		elif self.x0 <= 0 and deltaX < 0:
			deltaX = 0
		if self.y1 >= canvas.winfo_height() and deltaY > 0:
			deltaY = 0
		elif self.y0 <= 0 and deltaY < 0:
			deltaY = 0

		# tell the canvas to move the image of the ball over a bit
		self.canvas.move(self.name, deltaX, deltaY)

		# keep track of where the ball is
		self.x0 += deltaX
		self.x1 += deltaX
		self.y0 += deltaY
		self.y1 += deltaY

# make a window on the computer
window = Tk()

#set the size of the window
windowWidth = 800
windowHeight = 600
canvas = Canvas(window, width=windowWidth, height=windowHeight)
canvas.pack()

ball = Ball('theball', 'red', 10, 10, 30, 3, canvas)

# this loop never stops! It just keeps going till you quit the program
while True:
	# the animation happens here

	# if you want to move something around, you have to call it's "move()" 
	# method.  Here the ball is moved because we're callling the move() method
	ball.move()

	# wait a little bit before redrawing the canvas (20 ms)
	canvas.after(20)

	# show the canvas on the screen
	canvas.update()
	
window.mainloop()