[gDesklets] Newbie Developer Control Question

[Sean Bridges <sean mailcan com>]

Hello,
  I'm new to gdesklets and would like to develop a desklet.  I have read
through the excellent guides available on the site and am starting to
dive in.  I'm looking to make a 'picture frame' that will auto-cycle
through a directory of pictures.  Also I want it to display some picture
meta-data, namely IPTC/EXIF captions.  My question stems around Controls
and the best design approach.  

Control Functions would need to be:
* Handle grabbing Meta-data from image uri.  
* Handle building a list of uris to pictures to display based on a
passed directory.  Provide maybe a next picture, previous picture call
that is hooked to a timer.  (Doesn't appear to be a standard 'directory'
chooser preference, so that might have to just be a string for now?)

If I understand right each of these functions would need to happen
inside a control, not possible from a display.  Is that correct?  

I browsed through the controls on the site and I didn't find any that
appeared to help with this.  Is there anything out there that I should
re-use?  

Finally, if I have to make a control, I'm thinking it should be called
something like ImageManipulation.  Methods could be added do resizing or
transitions later down the road.  

Any advice or guidance would be appreciated.

Many thanks,
 Sean