> On 1 Oct 2015, at 07:57, Doug Hill <cocoa...@breaqz.com> wrote: > > There are few pieces of evidence that lead me to believe you that this hasn’t > been done: > > • A search of ADC site doesn’t show any sample code with this technique. > • A Google search turns up almost nothing, except the link I provided below. > • A search of all github and bitbucket public turns up no references to > estimatedItemSize. > > The funny thing is that I’ve implemented a dynamically sized table view cell > using the techniques described in the WWDC presentation, and it works great. > But there’s something about doing this with collection views that doesn’t > quite work. > > So, does Apple lie? > > Thanks. > > Doug Hill
Nope - you actually made me go and test it. Made a little UIView which has an intrinsic content size and can randomize that, and set invalidateIntrinsicContentSize() when it does). Put a UICollectionView in the storyboard and set up the one cell to have one of those views in it, pinned to all sides. Set up the datasource to make 1 section, 100 such cells and dequeued one cell for each. Started them all off at 150x150. Set collectionView.collectionViewLayout.estimatedSize to 100x100. Result, 150x150 boxes on the screen neatly laid out. Hooked up a button to iterate the cells on screen, find the embedded randomView and call its randomize function to reset the intrinsic content size, after they were all done, called collectionView.collectionViewLayout.invalidateLayout() Result, boxes all showed up in their new randomized sizes and the layout adjusted everything to fit, changed the number of boxes per line and the size of the lines. So just having cells with a fully-specified intrinsicContentSize and setting estimatedSize on the collection view flowlayout is enough to get dynamic cells without having to measure them or do any other work. So I deduce from that that Apple doesn’t lie and it does actually work as the WWDC session says. I did get some quite cool crashes when I set the estimated size far from the actual size, were I actually trying to do this for real I’d probably look into it but .. since I’m not. _______________________________________________ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
