Parsing *.nmea file with QNmeaPositionInfoSource class returns timeout.

[lazureus]

I'm trying to write simple application which is going to simulate GPS hardware device basing on already taken *.nmea log file. Technology which I chose is Qt5.4.1. because it already got class which should take care of the task which I'm trying to do. Class name is QNmeaPositionInfoSource. I supposed that by setting proper update interval timeout instance of QNmeaPositionInfoSource will notify me about new position. However, when I set interval to the 1s I'm getting only one position and after that timeout is notified. When I set interval to the 0, I'm getting immediatelly all notifications about position.

Here is my code:
source

Question is why I'm getting timeout notification?