def FlashLight():
phone = Ui.Phone()
lock = Ui.WakeLock()
try:
# no screen dim
lock.bright()
# set max screen brightness, but has no effect
old_bright = phone.brightness(255)
# show a white black screen
gui = Ui.TextView(background='#ffffffff')
gui.mainloop('FlashLight')
# restore screen brightness
phone.brightness(old_bright)
finally:
lock.release()
