[Aptitude-devel] Screenshot support is in the tree.

[Daniel Burrows]

  Hello list,

  I've been silent for a while due to a combination of real life stuff
and being too busy coding to write about coding. :)

  Anyway, I thought you all might be interested to know that I have
just completed and checked in an initial implementation of screenshot
support for aptitude.  Aside from where the screenshots show up in the
interface (only "Page 6" of the package information tab right now) and
a few minor internal tweaks I want to make, everything else seems to
work.

  This took longer than I expected, mostly because I ended up forcing
myself to do it "right".  This led to a bunch of follow-on changes:

  * enhancements to the file cache, which can now store last-modified
    dates (so we don't miss updated screenshots)
  * a global download queue for aptitude, with support for checking
    last-modified dates, announcing download status to the main thread,
    canceling downloads in progress, merging downloads of the same URI,
    adding new downloads to an existing queue, etc.  (basically a bunch
    of machinery to safely run an Acquire process in the background
    while still letting you inject into it)
  * a global cache of screenshot downloads for the GTK+ interface, to
    avoid loading the same screenshot into memory twice.

  Note that a global queue is probably the "right" solution here, since
the resources being accessed (network and disk) are also global.

  I think the download queue will be very nice for any future changes
that involve downloading from the network.  It could also be used to
enhance changelog downloads, although I don't think that's a high enough
priority item to actually do it right now. :-)

  Daniel