ChatLayout is an alternative solution to MessageKit. It uses custom
UICollectionViewLayout to provide you full control over the presentation as well as all the tools available in
ChatLayout is the custom
You don't have to extend or override any custom
UICollectionView. You need to instantiate them
yourself and use them the way you like.
ChatLayout does not rely on modified
UICollectionViewFlowLayout nor does it rotate your
This means you can use your views as if they would be regular cells within
UICollectionView. You can benefit from using the
UIKit implementations of
adjustedContextInsets (and others) because your view controller is a normal view
controller without any hacks or tricks.
ChatLayout doesn't require you to calculate all the cell sizes before it renders them on the screen. You can fully use
auto-layout constraints and rely on the fact that the correct size will be calculated in the runtime. However,
as any other
UICollectionViewLayout will benefit from you providing the estimated sizes of your cells as it will allow you
to get better performance.
ChatLayout doesn't enforce you to use any specific data model. You can store your messages and update
the way you like. The only thing you need is to respect the natural boundaries that
UICollectionView have and correctly
UICollectionViewDataSource. The Example app uses DifferenceKit to
process changes in the data model.
ChatLayout doesn't enforce you to use any specific
UIViews to create your collection cells. You can create them the way
you like. It can be any
UICollectionReusableView. There are some generic
UIViews bundled with
the library that may help you to build them faster. However, you do not have to use them.
ChatLayout doesn't handle the keyboard appearance behavior. You have to implement
that yourself from scratch or use the library you are already using in your project. It gives you full control over the
keyboard presentation. The only thing you have to do is to update the
contentInsets of your
ChatLayout doesn't provide you any input control. You can use any one you like and customise it the way you like.
The Example app for instance uses InputBarAccessoryView.
To run the example project, clone the repo, and run
pod install from the Example directory first.
If you are using cocoapods you can install the whole package using
pod 'ChatLayout'. If you do not need the additional
components provided, you can install only the layout itself using
ChatLayout is in active development, and we welcome your contributions.
If you’d like to contribute to this repo, please read the contribution guidelines.
ChatLayout can process any update commands that you send to your
UICollectionView, so you can use
UICollectionViewDiffableDataSource as well. But you have to keep in mind that
does not support the reloading of cells out of the box if you are relying on the
Hashable protocol implementation.
It will delete the changed cell and insert the new version of said cell. That may lead to strange animations on
the screen, especially when the reloaded cell changes its size. In order to get the best behaviour of the update animation
I would strongly recommend you rely on DifferenceKit or a similar library
to process the model changes. The Example app does it as well.
It can be tempting and it may look like it is the right way to go, but do not use supplementary views to decorate your
messages or groups of them.
UICollectionView processes them in a different order:
UICollectionViewCells first and
only after switches to
UICollectionReusableViews. You will most likely face some unexpected behaviour during the animation.
ChatLayout can be used together with Texture to improve the auto-layout performance.
But keep in mind that it's default wrapper is hardcoded to work exclusively with
You will have to implement
ChatLayoutDelegate yourself and propagate the node size manually.
If you see a strange or unexpected animation during the updates, check your data model and the commands you send to the
performBatchUpdates. Especialy if you are using some diffing algorithms like DifferenceKit.
It is very possible that you are sending delete/insert commands when you expect to see reload. The easiest way to check it is by adding
ChatLayout doesn't know what you expected to see.
It just processes your changes according to the commands it has received.
ChatLayout is distributed under the MIT license.
ChatLayout is provided for your use, free-of-charge, on an as-is basis. We make no guarantees, promises or
apologies. Caveat developer.
I am happy to answer any questions you may have. Just create a new issue.