Further development is ongoing !!
I had hoped that as the LCDd server implements icons, that it would be possible to drive the custom icons on the display using it's standard icon output, but sadly this doesn't seem to be the case.
All I ever get returned from the XBMC client is a 'filled block' icon which is obviously no use. I have, as a 'proof of concept' enabled some checking of the strings scrolling across the display to light such icons as 'music', 'tv', 'photos' etc but as this is not in the spirit of LCDproc, I would hesitate to continue down this route and I did it purely to ensure I was driving the display correctly.
Having looked at drivers for LCD's that have custom icons (imon/mdm166a) reveals that one can send raw data to LCDd,
provided the client supports doing this. This is how the custom icons are driven for those displays. If the client doesn't implement the raw output, then those icons will not work, but the basic display will.
So, as my driver implements the basics, we now have to turn to the client (in this case an add-on for XBMC) to see what information is returned. Looking at the code for the iMon driver, it appears that volume level and pretty much any icon I could want are supported for that display.
Unfortunately for me, it's all python, which means trying to get my head around another language
At this moment I think I would rather have it written in C !!!
Plans as of now are to fork the current development branch of the XBMC LCDproc add-on and try an implement icon support for my display. As all their code is GPL'd there's no problem doing that, or indeed hosting my own version of their addon.
It is an old case, and I doubt that there are all that many out there anymore, otherwise if I can get it working, I'd submit both the XBMC code and the LCDproc driver to the relevant places for inclusion in their software. I am however, very pleased to see my display working after several years of being blank and although it's limited in what it can do, I have no intentions of changing cases anytime soon.