How Do I Tell If A JPEG/SWF Has Loaded/Is Loading?

Question

I did a site for a photographer, loading an XML file and then
loading all the thumbnails and images.
At his request I loaded ALL the images at the beginning
(looped through XML file and loaded images one by one -- loading
each when previous one loaded)
Needless to say, this approach has a long front-loading time
(which I thoguht it would), and he wants to change it so that each
image is loaded as you click on it, AND the remaining images are
loaded in the background.
What's the best way to go about this? To have the other
images load on onEnterFrame? And then in the meantime if I want to
load a particular image I can do loadMovie() on it when the user
wants to see it.
But if I'm populating the array of other images in the
background and the user wants to see one I'm in the process of
loading, how do I handle that? Set a flag that says "I'm loading
this image", and another that says "this image is loaded"?
Do I need to use flags, or is there an inehrent property of
the movie clilp that I can test?
Thanks
Robert

Answer 1

Thanks. Then I could store a MovieClipLoader in my
picture-associated object and check when coming in from the outside
to see if <> undefined ?
My question has to do with "concurrency" -- that is, if in
one part of the program I'm running through an array of these
picture-objects, creating MovieClipLoaders and storing them in my
picture-object, but elsewhere in the program I'm looking for
mouseclicks and if a user wants to view a particular picture then I
go ahead and check the associated picture object to see if it's
already loading -- what lag, if any, is there in assigning the
MovieClipLoader in my bulk loading in the array and checking for it
in my mouseclick handling?
That is to say, if I have two parts of the program both
trying to load the same picture, I need a "lockout" so that they
don't both try to load it at the same time -- and this "lockout"
would be the MovieClipLoader -- one or the other will do new
MovieClipLoader() and the other will check for this before trying
to create it. But what I'm curious about is whether there is a lag
between one part of the programming checking for this and creating
it, and the other part checking for it -- and how to deal with
that.