Summary:
Because we trampoline to main when setting _currentImageQuality, there would be situations where displayWillStart was called, we get a cached image and set currentImageQuality to 1.0, and then a background thread calling setDefaultImage would enqueue an operation that sets currentImageQuality to 0 and overwrites the correct value
Calling _updateProgressImageBlockOnDownloaderIfNeeded should be called without _lock held. We will lock super to read our interface state and it's best to avoid acquiring both locks.
Summary:
Use NSData as key
Add chunking of files
Add support for Animated Images
This adds support for GIF playback in ASDK. It's not currently ready
for merging to public ASDK – for one the GIF decompression may make
more sense in PINRemoteImage.
Removed duration as it wasn't used
Make cover image lazily loaded
Differential Revision: https://phabricator.pinadmin.com/D82033
If previously-displayed contents is gone (e.g. clearContents), and is not finished displaying
by the time the node is onscreen, recreate the placeholder immediately.
Destruction of bigger images in ASNetworkImageNode on the main thread can be expensive and can take some time, so we dispatch onto a background queue to actually dealloc.
This should not directly affect more complex apps that don't use the ASBasicImageDownloader.
Also disables the default-on text placeholders, as they churn memory during the measurement pass.
These were intended to be written with pure layers (without using backing stores), so I don't
think it is a reasonable default-on behavior until that is fixed.
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.
