[GSoC] Impress Remote and Bonjour

[Andrzej J. R. Hunt]

On Sun, 2013-07-21 at 14:17 +0200, Siqi Liu wrote:
> Hello all again, 

> 
> 
> I've done several tests today and I've found that the old
> implementation indeed works under certain conditions, so I've restored
> it. However, it only seems to work when the LibreOffice instance is
> already launched on the PC and only then, when we start the android
> app, we can see that. And when we close the LibO instance, it doesn't
> disappear either. Anyway, I think it would be great to make android
> app compatible with the avahi/bonjour service (not really sure if
> that's possible) so that we can get it to work more reliably not the
> other way around... 
> 
Would be interesting to see -- the reason I implemented the custom
discovery protocol was because mdns support on android is apparently
somewhat patchy -- things are supposed to have improved in newer
versions (4.0+ I believe), but I haven't tested recently, and there are
still plenty of devices with older versions of Android around.

No idea why the custom protocol is so patchy though -- is this using the
Android client? LO definitely has to be launched as it listens for
multicast packets from the client (which the client sends every 10s or
so) and responds to the client to let it know its existence -- might be
worth adding some code to the server side to
(1) Show the IP in the remote dialog.
(2) Show a message to the user if either of the remote ports
    is already in use?
If we could detect firewall issues as well that would be good but no
idea if that's even doable.

I've also noticed a possible bug to do with the timeout/search interval
in the android app, whereby a while loop could possibly be spinning
empty for 5 seconds at a time every 15 seconds (I didn't do much testing
of this at the time as I was trying to get Bluetooth working then and
after that never used the networked option again...) -- I'll try and fix
and test that during the course of this week.

However using Avahi/Bonjour is definitely preferable when available.

ATB,
	Andrzej