Added preloading items, defaults to 0

[coneybeare]

#34

I added some preloading items to assist with views that grab content from the web. This prevents flickering for the most part, as long as the user swipes at a normal pace. It defaults to 0 items preloaded, other than any of the existing preloaded views from the visibleInidices

[vassily-fr]

You should also not unload view that are in preloading arrays :
//remove offscreen views
for (NSNumber *number in [_itemViews allKeys])
{
if (![visibleIndices containsObject:number] && ![preloadedIndices containsObject:number])
{
DLog(@"unloading view at index %@",number);
UIView *view = _itemViews[number];
[self queueItemView:view];
[view removeFromSuperview];
[_itemViews removeObjectForKey:number];
}
}

[fernandomatal]

Any updates about this? Sounds like a good idea.

[lewis-smith]

I've been using this for a long time and it works fine and improves response time.