from __future__ import with_statement
from Xlib.display import Display
import time

def get_focus():
    focus = Display().get_input_focus()
    return (focus.focus.get_wm_name(), focus.focus.get_wm_class())

def main():
    (wm_name, wm_class) = get_focus()
    with open("test.log", 'a+') as fileHandle:
        fileHandle.write("%s %s %s\n" % (time.asctime(), wm_name, wm_class, ))
        while (1):
            if (wm_name, wm_class) != get_focus():
                wm_name, wm_class = get_focus()
                fileHandle.write("%s %s %s\n" % (time.asctime(), wm_name, wm_class, ))
            time.sleep(3)

if __name__ == "__main__":
	main()