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* Introduce ASCollectionViewLayout - `ASCollectionViewLayout` is an async `UICollectionViewLayout` that encapsulates its layout calculation logic into a separate thread-safe object which can be used ahead of time and/or on multiple threads. - `ASDataController` now can prepare for a new layout resulted from a change set before `ASCollectionView` even knows about it. By the time the change set it ready to be consumed by `ASCollectionView`, its new layout is also ready. - New `ASCollectionViewLayoutCalculating` protocol that is simple and generic enough that many types of calculators can be built on top. `ASCollectionViewLayoutSpecCalculator` conforms to `ASCollectionViewLayoutCalculating` protocol and can be backed by any layout spec (e.g `ASStackLayoutSpec`, `PIMasonryLayoutSpec`, etc). We can even build a `ASCollectionViewLayoutYogaCalculator` that uses Yoga internally. - A built-in `ASCollectionViewFlowLayoutCalculator` that is a subclass of `ASCollectionViewLayoutSpecCalculator` and uses a multi-threaded multi-line `ASStackLayoutSpec` internally. The result is a performant and thread-safe flow layout calculator. - Finally, `ASCollectionViewLayout` can be subclassed to handle a specific type of calculator with optimizations implemented based on the knowledge of such calculator. For example, `ASCollectionViewFlowLayout` can have a highly optimized implementation of `-layoutAttributesForElementsInRect:`. Protocolize layout calculator providing and consuming Add flex wrap documentation Add a `multithreaded` flag to ASStackLayoutSpec that forces it to dispatch even if it's off main - Update ASCollectionViewFlowLayoutSpecCalculator to use that flag. Minor change in ASCollectionViewLayout Implement Mosaic layout calculator Minor change Fix project file Rename and fix project file Skip fetching constrained size only if a layout calculator is available Update examples/ASCollectionView Remove unnecessary change in ASTableView Address comments Rename collection view calculator protocols Minor changes after rebasing with master Add ASLegacyCollectionLayoutCalculator for backward compatibility Remove ASCollectionLayoutSpecCalculator Remove ASLegacyCollectionLayoutCalculator Introduce ASCollectionLayout - A wrapper object that contains content size and an element to rect table. - Collection layout calculators to return this new object instead of an ASLayout. Before adding a content cache Finishing hooking up ASCollectionLayoutDataSource to ASCollectionNode Stash Finish ASCollectionLayout Rough impl of ASCollectionFlowLayout Revert changes in CustomCollectionView example Move ASRectTable back to Private * Rename ASCollectionContentAttributes to ASCollectionLayoutState * Address other comments * Introduce ASCollectionLayoutDelegate and make ASCollectionLayout private * Address comments * API tweaks: - Replace `-layoutContextWithElementMap:` in ASCollectionLayoutDelegate with `-additionalInfoForLayoutWithElements:`. The returned object is then stored in ASCollectionLayoutContext for later lookups. - ASCollectionLayoutContext has no public initializer. - ASDataControllerLayoutDelegate no longer requires a context of type ASCollectionLayoutContext but simply an `id`. This helps decouple ASDataController and ASCollectionLayout. - Rename `elementMap` to `elements`. - Rename `visibleMap` to `visibleElements`. - Other minor changes. * Rename ASCGSizeHash to ASHashFromCGSize * Make sure to call super in -[ASCollectionLayout prepareLayout] * Update example/ASCollectionView to use ASCollectionFlowLayoutDelegate * Remove unnecessary change
Installation
ASDK is available via CocoaPods or Carthage. See our Installation guide for instructions.
Performance Gains
AsyncDisplayKit's basic unit is the node. An ASDisplayNode is an abstraction over UIView, which in turn is an abstraction over CALayer. Unlike views, which can only be used on the main thread, nodes are thread-safe: you can instantiate and configure entire hierarchies of them in parallel on background threads.
To keep its user interface smooth and responsive, your app should render at 60 frames per second — the gold standard on iOS. This means the main thread has one-sixtieth of a second to push each frame. That's 16 milliseconds to execute all layout and drawing code! And because of system overhead, your code usually has less than ten milliseconds to run before it causes a frame drop.
AsyncDisplayKit lets you move image decoding, text sizing and rendering, layout, and other expensive UI operations off the main thread, to keep the main thread available to respond to user interaction.
Advanced Developer Features
As the framework has grown, many features have been added that can save developers tons of time by eliminating common boilerplate style structures common in modern iOS apps. If you've ever dealt with cell reuse bugs, tried to performantly preload data for a page or scroll style interface or even just tried to keep your app from dropping too many frames you can benefit from integrating ASDK.
Learn More
- Read the our Getting Started guide
- Get the sample projects
- Browse the API reference
Getting Help
We use Slack for real-time debugging, community updates, and general talk about ASDK. Signup yourself or email AsyncDisplayKit(at)gmail.com to get an invite.
Contributing
We welcome any contributions. See the CONTRIBUTING file for how to get involved.
License
AsyncDisplayKit is BSD-licensed. We also provide an additional patent grant. The files in the /examples directory are licensed under a separate license as specified in each file; documentation is licensed CC-BY-4.0.