Before, it was expensive to check this value, even though it was rarely set.
Now the cost is moved to setting the value, and is made very cheap to check with _hierarchyState.
This avoids CoreAnimation from capturing the name from a background thread deep within the internals
of AVPlayerLayer, which commits transactions off the main thread. If the main thread is also accessing
properties that require the lock, in very specific app architectures relying on AVPlayerLayer, this
can cause a deadlock.
The "name" property is primarily used by ASDK's unit test infrastructure, so I'm leaving it in place for
that purpose - and it may still be used for debugging, if someone wants to set it. It will remain
possible to get the node from a layer or view with asyncdisplaykit_node, and access name from there.
Later, this will be added to ASViewController. Right now it is not hooked up to drive anything.
It will become the codepath that drives calls like -fetchData and -clearContents.
This ensures memory cleanup happens correctly and introduces a new test project
to support developing new features while stressing tough use cases for correctness.
- They are neither considered internally nor in tests. And when they are accidently considered, they cause tests to fail.
- Developers can easily set debugging names themselves whenever needed.
This provides internal features on _ASAsyncTransaction and ASDisplayNode to facilitate
implementing public API that allows clients to choose if they would prefer to block
on the completion of unfinished rendering, rather than allow a placeholder state to
become visible.
The internal features are:
-[_ASAsyncTransaction waitUntilComplete]
-[ASDisplayNode recursivelyEnsureDisplay]
Also provided are two such implementations:
-[ASCellNode setNeverShowPlaceholders:], which integrates with both Tables and Collections
-[ASViewController setNeverShowPlaceholders:], which should work with Nav and Tab controllers.
Lastly, on ASDisplayNode, a new property .shouldBypassEnsureDisplay allows individual node types
to exempt themselves from blocking the main thread on their display.
By implementing the feature at the ASCellNode level rather than ASTableView & ASCollectionView,
developers can retain fine-grained control on display characteristics. For example, certain
cell types may be appropriate to display to the user with placeholders, whereas others may not.
Follow-up work will include unit tests, revisiting names, and the header locations of definitions.
