symbian-qemu-0.9.1-12/python-2.6.1/Demo/tkinter/guido/brownian2.py
author johnathan.white@2718R8BGH51.accenture.com
Mon, 08 Mar 2010 18:45:03 +0000
changeset 46 b6935a90ca64
parent 1 2fb8b9db1c86
permissions -rw-r--r--
Modify framebuffer and NGA framebuffer to read screen size from board model dtb file. Optimise memory usuage of frame buffer Add example minigui application with hooks to profiler (which writes results to S:\). Modified NGA framebuffer to run its own dfc queue at high priority

# Brownian motion -- an example of a NON multi-threaded Tkinter program ;)
# By Michele Simoniato, inspired by brownian.py

from Tkinter import *
import random
import sys

WIDTH = 400
HEIGHT = 300
SIGMA = 10
BUZZ = 2
RADIUS = 2
LAMBDA = 10
FILL = 'red'

stop = 0                                # Set when main loop exits
root = None                             # main window

def particle(canvas):                   # particle = iterator over the moves
    r = RADIUS
    x = random.gauss(WIDTH/2.0, SIGMA)
    y = random.gauss(HEIGHT/2.0, SIGMA)
    p = canvas.create_oval(x-r, y-r, x+r, y+r, fill=FILL)
    while not stop:
        dx = random.gauss(0, BUZZ)
        dy = random.gauss(0, BUZZ)
        try:
            canvas.move(p, dx, dy)
        except TclError:
            break
        else:
            yield None

def move(particle): # move the particle at random time
    particle.next()
    dt = random.expovariate(LAMBDA)
    root.after(int(dt*1000), move, particle)

def main():
    global root, stop
    root = Tk()
    canvas = Canvas(root, width=WIDTH, height=HEIGHT)
    canvas.pack(fill='both', expand=1)
    np = 30
    if sys.argv[1:]:
        np = int(sys.argv[1])
    for i in range(np):                  # start the dance
        move(particle(canvas))
    try:
        root.mainloop()
    finally:
        stop = 1

if __name__ == '__main__':
    main()