Hello, found that problem, what is this? my mistake? Scrolling just stop, if there big one cell without 2 small, but i can see it while bouncing collectionview I like your job, and want to implement in my project, but does it work only with even counts of items?

swift 3 version (ios10) xcode 8 beta6, compiled with COCOAPODS: 1.1.0.beta.2

it compiles, runs, images are shown, but scrolling breaks app.

This is my first pull request, I hope I do it right

Stacktrace tail:

Library/Caches/com.apple.xbs/Sources/UIKit_Sim/UIKit-3599.5/UICollectionViewData.m:709
2016-09-08 17:37:02.006 TRMosaicLayout_Example[58384:4207508] *** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'no UICollectionViewLayoutAttributes instance for -layoutAttributesForItemAtIndexPath: <NSIndexPath: 0x610000036f60> {length = 2, path = 0 - 12}'
*** First throw call stack:
(
    0   CoreFoundation                      0x000000010cdf334b __exceptionPreprocess + 171
    1   libobjc.A.dylib                     0x000000010c85421e objc_exception_throw + 48
    2   CoreFoundation                      0x000000010cdf7442 +[NSException raise:format:arguments:] + 98
    3   Foundation                          0x000000010c3eaedd -[NSAssertionHandler handleFailureInMethod:object:file:lineNumber:description:] + 195
    4   UIKit                               0x000000010db9ff70 -[UICollectionViewData layoutAttributesForItemAtIndexPath:] + 670
    5   UIKit                               0x000000010db4df0a -[UICollectionView _dequeueReusableViewOfKind:withIdentifier:forIndexPath:viewCategory:] + 384
    6   UIKit                               0x000000010db4e9db -[UICollectionView dequeueReusableCellWithReuseIdentifier:forIndexPath:] + 169
    7   TRMosaicLayout_Example              0x000000010c1b782e _TFC22TRMosaicLayout_Example26TRCollectionViewController14collectionViewfTCSo16UICollectionView13cellForItemAtV10Foundation9IndexPath_CSo20UICollectionViewCell + 206
    8   TRMosaicLayout_Example              0x000000010c1b7df7 _TToFC22TRMosaicLayout_Example26TRCollectionViewController14collectionViewfTCSo16UICollectionView13cellForItemAtV10Foundation9IndexPath_CSo20UICollectionViewCell + 87
    9   UIKit                               0x000000010db39b27 -[UICollectionView _createPreparedCellForItemAtIndexPath:withLayoutAttributes:applyAttributes:isFocused:notify:] + 467
    10  UIKit                               0x000000010db3b71c -[UICollectionView _prefetchItemsForVelocity:maxItemsToPrefetch:invalidateCandidatesOnDirectionChanges:] + 398
    11  UIKit                               0x000000010db44c4e -[UICollectionView layoutSubviews] + 717
    12  UIKit                               0x000000010d2daae4 -[UIView(CALayerDelegate) layoutSublayersOfLayer:] + 1237
    13  QuartzCore                          0x000000011316fcdc -[CALayer layoutSublayers] + 146
    14  QuartzCore                          0x00000001131637a0 _ZN2CA5Layer16layout_if_neededEPNS_11TransactionE + 366
    15  QuartzCore                          0x000000011316361e _ZN2CA5Layer28layout_and_display_if_neededEPNS_11TransactionE + 24
    16  QuartzCore                          0x00000001130f162c _ZN2CA7Context18commit_transactionEPNS_11TransactionE + 280
    17  QuartzCore                          0x000000011311e713 _ZN2CA11Transaction6commitEv + 475
    18  QuartzCore                          0x000000011311f083 _ZN2CA11Transaction17observer_callbackEP19__CFRunLoopObservermPv + 113
    19  CoreFoundation                      0x000000010cd97e17 __CFRUNLOOP_IS_CALLING_OUT_TO_AN_OBSERVER_CALLBACK_FUNCTION__ + 23
    20  CoreFoundation                      0x000000010cd97d87 __CFRunLoopDoObservers + 391
    21  CoreFoundation                      0x000000010cd7cb9e __CFRunLoopRun + 1198
    22  CoreFoundation                      0x000000010cd7c494 CFRunLoopRunSpecific + 420
    23  GraphicsServices                    0x000000011297fa6f GSEventRunModal + 161
    24  UIKit                               0x000000010d216a74 UIApplicationMain + 159
    25  TRMosaicLayout_Example              0x000000010c1b994f main + 111
    26  libdyld.dylib                       0x00000001108e068d start + 1
    27  ???                                 0x0000000000000001 0x0 + 1
)
libc++abi.dylib: terminating with uncaught exception of type NSException
(lldb) 

Hi,

Your library is great! Just found out that collection view isn't scrolling to the last item if the item count is not divisible by 3..it happens in your example code too.. Could you please fix it?

Thanks

Hi there,

I am sorry, to maybe ask a stupid question.

I've installed all proberly. The demo is running nicely with the Asset book images. (y)

Now my problem:

I installed TRMosaikLayout by cocoapods. I am using XCode8 beta6. I copied the TRCollectionViewController code into an empty UICollectionViewController class. I added a UICollectionViewController onto my storyboard I changed the reuseIdentifier to the proberly name Added the Assets you provide in your example I changed the cell color to any color (for testing) Run the project, but cellForItemAt indexPathwas never called.

After a few hours of doom, I commented out the

   ` // self.collectionView!.collectionViewLayout = mosaicLayout`

Now it shows me the cells regularly. But not as Mosaiks. When I comment in this line, the mosaiklayout stays empty.

The cellForItemAt indexPath function don't get called.

What I am missing, what should I do?

Many thanks in advance

Changes

• add @objc prefix to protocol and enum
• add type to the enum

Would be great to prepare whole library little bit better for Obj-C so anybody can use it.

Thanks for merging ASAP so we don't need to use our forks @vinnyoodles. :)

EDIT: Also updated example project, fixed cocoapods and some other improvements.

I was watching the latest WWDC and they had a section called "A Tour of UICollectionView". In this section, the instructor creates a mosaic layout like yours by creating a subclass of UICollectionViewLayout just like TRMosaicLayout. Yet the instructor optimizes the layout for scrolling within the layoutAttributesForElements by changing the method from a linear search to a binary. Binary searches are somewhat new to me, so after rewatching the video and doing some research, I found the collection needs to be sorted to be able to run a binary search. My problem is I get a bit confused on how to create the binary search and if your cachedCellLayoutAttributes are sorted already. In the video the instructor says the cachedCallLayoutAttributes are sorted by there frames minimum y value, yet when i debug cachedCellLayoutAttributes it seems that the there frames minimum y value isn't sorted. If you have any ideas or if its even worth doing in the first place let me know. I'll add video link and specific time of video below.

https://developer.apple.com/videos/play/wwdc2018/225/ Specific time about optimization within layoutAttributesForElements: 25:40 -> 28:00

The following delegate should be weak: open var delegate: TRMosaicLayoutDelegate! Being a strong reference lead to a retain cycle on any controller using this delegate.

I will propose a PR soon to fix this if you don't mind.

It seems the right inset is not as large as what it should be. I set the same value as the left and right insets. But the right displayed inset is smaller than the left.

This is a superb layout library, but I am facing a serious problem.

collectionView.register(UINib(nibName: "LoadingFooterCollectionReusableView", bundle: nil), forSupplementaryViewOfKind: UICollectionElementKindSectionFooter, withReuseIdentifier: "loadingFooterIdentifier");

//The delegate function below is no longer called func collectionView(_ collectionView: UICollectionView, viewForSupplementaryElementOfKind kind: String, at indexPath: IndexPath) -> UICollectionReusableView { }

Any ideas how to fix this?