Trigger fetch on upper scrolling?

[flynnpc-swca]

Hello. Thank you for creating and maintaining this library. It has been very useful. I do have a question about potentially triggering fetch when the user scrolls up. Could the observer be modified to trigger either fetch or another method when the user scrolls back up? I ask because we are trying to only maintain about 100-300 Photo objects in memory at a time. Our app will potentially serve thousands of photos across various tabs. My initial thought is to use fetch to query for new photos and push and unshift the Photos array so that there is only a set amount in memory. Are you considering adding this scroll up fetching capability by any chance?

[igordanchenko]

Hi,

First off, can you describe the problem you are trying to solve? Can you share an example demonstrating the issue you are experiencing?

I'm assuming you are concerned about potential out-of-memory condition, but I'm not sure I completely understand your concern / scenario. How big are your Photo objects? With a typical Photo object (src, width, height) being as small as a few hundred bytes, keeping as many as 100,000 of objects in memory would be a matter of just several dozen megabytes (which is comparable to a handful of high-resolution images)