ZaBlanc/WebImageView — pull request #4 by aiwilliams (2012-07-10 17:08:57+00:00)
Title: Images assigned to wrong view when retriever completes.

When we scroll a list view, the ```WebImageView```s are reused. Even when a memory or disk cache is used, the retrieval process can take long enough that when it completes, the view has been repurposed. Even though the ```cancelForWebImageView``` method will attempt to deal with this, it doesn't succeed since there is another mapping of the view to the retriever, so that when the retriever has completed, it overwrites the view with an "old" image.

Our solution is to maintain a mapping of the view to the url it wants. To 'cancel' really means to simply not care about that url anymore. That may not be needful since when the view is repurposed, it simply replaces the associated url. When the retriever completes, any view that cares about it's url receives the bitmap.