Right now when an image node enters preload state, we kick off an image request with the default priority. Then when it enters display state, we change the priority to "imminent" which is mapped to the default priority as well. This means that requests from preload and display nodes have the same priority and are put to the same pool. The right behavior would be that preload requests should have a lower priority from the beginning.
Another problem is that, due to the execution order of -didEnter(Preload|Display|Visible)State calls, a node may kick off a low priority request when it enters preload state even though it knows that it's also visible. By the time -didEnterVisibleState is called, the low priority request may have already been consumed and the download/data task won't pick up the new higher priority, or some work needs to be done to move it to another queue. A better behavior would be to always use the current interface state to determine the priority. This means that visible nodes will kick off high priority requests as soon as -didEnterPreloadState is called.
The last (and smaller) issue is that a node marks its request as preload/low priority as soon as it exits visible state. I'd argue that this is too agressive. It may be reasonble for nodes in the trailing direction. Even so, we already handle this case by (almost always) have smaller trailing buffers. So this diff makes sure that nodes that exited visible state will have imminent/default priority if they remain in the display range.
All of these new behaviors are wrapped in an experiment and will be tested carefully before being rolled out.
* Add imports
* Fix build failure
* Encapsulate common logics into methods
* Address comments
* [License] Simplify the Texture license to be pure Apache 2 (removing ASDK-Licenses)
With permission of the Facebook Open Source team, we are simplifying the Texture
license so that clients can rely on the Apache 2 terms that most of Texture is
already covered by. This means that code originally forked from AsyncDisplayKit
will be re-licensed from "BSD 3-clause + PATENTS v2" to Apache 2 without a
PATENTS file.
After getting confirmation that the updates to these core files look good, we'll
propagate this new license header to all files (in this same PR) and get sign-off
from all parties before landing.
* [License] Update all Texture source files to be pure Apache 2.
* Changelog entry for Apache 2 license update.
* Revert "[License] Update all Texture source files to be pure Apache 2."
This reverts commit ffa0fbbba9717d871dd16c4b07539f2f8208fc2b.
* [License] Update all Texture source files to be pure Apache 2, maintaining copyrights.
* [License] Update CONTRIBUTING, README, Podspec & Dangerfile.
* [ASDisplayNode] Add safeAreaInsets, layoutMargins and related properties to ASDisplayNode
* Add layoutMargins bridged to the underlying view
* Add safeAreaInsets bridged to the underlying view
* Add fallback calculation of safeAreaInsets for old iOS versions
* Add automaticallyRelayoutOnSafeAreaChanges and automaticallyRelayoutOnLayoutMarginsChanges properties
* Add additionalSafeAreaInsets property to ASViewController for compatibility with old iOS versions
* Provide safeAreaInsets for layer-backed nodes.
This also fixes tests.
* Fix crash when insetsLayoutMarginsFromSafeArea is set from a background thread
* Changes requested at code review:
* Update documentation for layoutMargins and safeAreaInsets properties. Suggest that users set the automaticallyRelayout* flags to ensure that their layout is synchronized to the margin's values.
* Fix accessing ASDisplayNode internal structures without a lock.
* Add shortcut in -[ASDisplayNode _fallbackUpdateSafeAreaOnChildren] to skip a child when possible.
* Add shortcut in ASViewController to avoid fallback safe area insets recalculation in iOS 11. Fix fallback safe area insets recalculation when the additionalSafeAreaInsets are set.
* Add debug check that a view controller's node is never reused without its view controller, so the viewControllerRoot flag value is always consistent.
* Use getters instead of reading ivars directly in -layoutMarginsDidChange and -safeAreaInsetsDidChange.
* Minor change in CHANGELOG
* Minor change in ASDisplayNodeTests.mm
* - [ASDisplayNode] Consolidate main thread initialization and allow apps to invoke it manually instead of +load.
Additionally this has a few minor fixes for Yoga support, and adds some basic
but universally valuable callbacks like -nodeDidLoad to ASNodeController.
* Small fix for handling _layoutVersion.
* Remove poking the scale accessor
* Make our async deallocation functions take a double pointer, so we can be sure we've released before the queue drains
* Make it a class property
* Fix the return type
* Use a locker
* Improve release notes
* Implement tests for the layout flattening process
* Refactor the flattening algorithm
- Remove flattened flag
- No more self check
- Stop traversing a layout tree branch when hits a displaynode node.
- Reuse as many existing ASLayout objects as possible
* Update changelog
* Ceil position values before comparing
* Explain why sublayout elements must be retained
