bubbles.py

from Tkinter import *
import random
import colorsys
import sys

class Bubble(object):
  def __init__(self, cv, min_size, max_size, x_bound, y_bound):
    self.size = min_size + random.randrange(0, max_size - min_size)
    self.x = random.randrange(0, x_bound)
    self.y = random.randrange(0, y_bound)
    self.iteration = 0
    self.cv = cv

    # Using an oval instead of an arc because the user should be able to select the inner circle.
    self.obj = cv.create_oval(self.x, self.y, self.x + self.size, self.y + self.size, fill="", outline=self.get_colour(), width="1")
    self.cv.pack()
    self.cv.after(200, self.next_iteration)

  def get_colour(self):
    value = (self.size - self.iteration) / 100.0
    h, l, s = 0.8 - value / 10.0, value, 0.6
    r, g, b = map(self.rgbify, colorsys.hls_to_rgb(h, l, s))
    return "#%02x%02x%02x" % (r, g, b)

  def rgbify(self, value):
    x = value * 255 - 15
    return x if x > 0 else 0

  def next_iteration(self):
    self.iteration += 1
    self.cv.delete(self.obj)
    if self.iteration < self.size / 2:
      self.cv.after(200, self.next_iteration)

      x1 = self.x + self.iteration
      y1 = self.y + self.iteration
      x2 = self.x + self.size - self.iteration
      y2 = self.y + self.size - self.iteration
      self.obj = self.cv.create_oval(x1, y1, x2, y2, fill="", outline=self.get_colour(), width="1")

class App(object):
  def __init__(self):
    self.min_size = 20
    self.max_size = 70
    self.frequency = 30
    if len(sys.argv) == 2:
      self.frequency = int(sys.argv[1])

    self.root = Tk()
    self.root.title("Bubbles!")
    self.root.attributes("-alpha", 0.9)
    self.cv = Canvas(self.root, width=600, height=400)
    self.cv.pack(expand=True, fill=BOTH)

    self.root.after(self.frequency, self.new_bubble)
    self.root.bind("<Configure>", self.resize)
    self.root.bind("f", lambda e: self.cv.delete("all"))
    self.root.bind("=", lambda e: self.change_freq(1))
    self.root.bind("-", lambda e: self.change_freq(-1))
    self.root.bind("q", lambda e: e.widget.quit())
    self.root.mainloop()

  def resize(self, event):
    self.w = event.width
    self.h = event.height

  def change_freq(self, value):
    self.frequency -= value

  def new_bubble(self):
    Bubble(self.cv, self.min_size, self.max_size, self.w, self.h)
    self.root.after(self.frequency, self.new_bubble)

App()