Maintaining 'focus' on Leap Motion Python (IDLE) code execution

Question

When executing Leap-Motion-centric code in the Python IDLE, switching to another window makes the IDLE disregard the Leap controller and stop processing frames. How can this be avoided so that, say, the Leap gestures can be used to interact with other windows?

Not really relevant, but code to reproduce this problem:

import Leap
from Leap import *

class FocusListener(Leap.Listener):
    def on_frame(self, controller):
        frame = controller.frame()
        print frame

def main():
    # Create a sample listener and controller
    listener = FocusListener()
    controller = Leap.Controller()

    controller.add_listener(listener)

    while (1):
        listener.on_frame(controller)


if __name__ == "__main__":
    main()

PS: Might this have something to do with the fact that I'm 'synthetically' looping the frame with the while?

Answer 1

To get frames while your app isn't focused, you need to set the "background frames" policy:

controller.set_policy_flags(Leap.Controller.POLICY_BACKGROUND_FRAMES);

See: https://developer.leapmotion.com/documentation/python/api/Leap.Controller.html#Leap.Controller.set_policy_flags