Simple Cairo animation

#!/usr/bin/env python3.3

from gi.repository import Gtk, Gdk, GLib
import cairo, math, time


class MyWindow (Gtk.Window):
    def __init__ (self):
        super().__init__(title="CairoAnim Test")
        self.set_default_size(200, 220)
        self.connect_after('destroy', self.destroy)

        self.canvas = Gtk.DrawingArea()
        self.canvas.set_size_request(200, 200)
        self.canvas.connect('draw', self.draw)

        self.fpslabel = Gtk.Label()

        self.box = Gtk.VBox()
        self.box.pack_start(self.canvas, False, False, 0)
        self.box.pack_start(self.fpslabel, True, False, 0)
        self.add(self.box)

        self.show_all()

        self.frames = 0
        self.lastFrame = 0
        self.fps = 0
        self.lastFps = time.time()
        self.getFps()
        GLib.timeout_add(16, self.update) # 16 ms per frame = 60 frames per second

    def getFps (self):
        if time.time() - self.lastFps > 1:
            self.fpslabel.set_markup("FPS: <b>{0}</b>".format(self.fps))
            self.fps = 0
            self.lastFps += 1
        self.fps += 1

    def destroy (window, self):
        Gtk.main_quit()

    def update (self):
        self.canvas.queue_draw()
        self.frames += 1
        self.getFps()
        return True

    def draw (self, da, ctx):
        ctx.set_line_width(2)
        ctx.set_source_rgb(0.8, 0, 0)
        ctx.arc(100, 100, abs(math.sin(time.time()))*90, 0, 2 * math.pi)
        ctx.stroke()

        ctx.set_source_rgb(0, 0.8, 0)
        ctx.arc(100, 100, abs(math.sin(time.time()*2+90))*90, 0, 2 * math.pi)
        ctx.stroke()

        ctx.set_source_rgb(0, 0, 0.8)
        ctx.arc(100, 100, abs(math.sin(time.time()+180))*90, 0, 2 * math.pi)
        ctx.stroke()

if __name__ == "__main__":
    app = MyWindow()
    Gtk.main()