[rocon_remocon] problem of web app pairing mode

[dwlee]

Generally, In pairing mode, When rapp is launched, the remocon remembered the interaction information with launched rapp and registered the callback function called when rapp died. So, when the rapp is terminate, the registered callback is called and then the pairing app running in pc or robot is stopped by interaction manager.
However, in case of web app (using web browser) pairing mode, it died as soon as it is stared by remocon. So, the remocon decides that web app died and pairing app is terminated. I think the problem is the starting method of web browser in python.

[stonier]

Problem is here

process = rocon_python_utils.system.Popen([web_browser, "--new-window", url], postexec_fn=process_listener)

It looks like this call returns immediately (not blocking) so if it's paired, it will close down the pairing immediately.

[stonier]

If browsers can't help us here, we need either

1. Maybe Qt webkit to help us watchdog it (horrible web app support?) OR
2. Web apps have to send a ping 'I'm alive' signal (sounds complicated?)