* Revert "Revert "[ASLayoutSpec] Use childrenMap directly to prevent creating an NSArray within ASDK (#1937)""
This reverts commit 735b4ebd0872483044d98a5d05b43324e76fc8d4.
* Fix crash and add exception for mutating while using fast enumeration of ASLayoutSpec children
NSFastEnumeration is potentially quite dangerous in the wrong hands. In particular, it does not provide a safe mechanism for you to return temporary objects directly, and it does not provide any guarantee that you will be called when the enumeration has completed; therefore if we generate temporaries and store them in an instance variable, we will not necessarily be able to clean them up! This means fast enumeration methods should never be called within an autorelease pool or the autorelease pool be drained within the fast enumeration loop.
The reason is we store references to objects in the stackBuf struct by casting the child pointer to __autoreleasing id. If we pop the autorelease pool between calls to -countByEnumeratingWithState:objects:count:, it will die in a messy explosion of pointer dereferences and EXC_BAD_ACCESS.
* Add tests for ASDisplayNode and ASLayoutSpec fast enumeration
Something interesting going on here with ARC / Objective-C++ that we are investigating and will re-land.
This reverts commit c90ed08d1073701e2c7f8a2677d460c140f05264.
* Use childrenMap directly to prevent creating an NSArray in ASDK for ASLayoutSpec children
* Add locking for parent property in ASLayoutSpec
* Remove unnecessary import
* Add newline
* Add NSFastEnumeration to ASEnvironment and ASDisplayNode / ASLayoutSpec
* Change NSMutableArray initializer to arrayWithCapacity:
* Move ASLayoutSpec+Private.h into Private folder
Fixes building with Swift
* Remove lock for ASLayoutSpec parent
* [ASEnvironmentTraitCollection] default user interface idiom to ASEnvironmentTraitCollection
UIUserInterfaceIdiomUnspecified is -1 so we were actually defaulting our trait collection to UIUserInterfaceIdiomPhone (which is 0).
* Fix a few places where we weren’t using the default method to create the base traits
Passing around a pointer was leading to crashes as the ASVC was the sole owner of the context. There are cases where the VC would dealloc while its subnodes were laying out. This could lead to the subnodes accessing a garbage pointer.
* Perhaps controversially, decomposing ASRangeControllerUpdateRangeProtocol+Beta.h such that the categories on various classes are defined in the classes themselves since that's where the implementation of those categories is provided.
* Updating unit tests and import other headers the tests took for granted. The tests could probably import the umbrella header and not have to worry about this.
* Updating the "Life without Cocoapods" sample to build and run dependent on ASDK as a static library.
* Added a "Life With Frameworks" sample app to build and run dependent on ASDK as a framework, proving the framework targets work.
* Don't relayout as a result of clearing a traitCollection's context
I'm not completely sure this change is the best solution. Here is context:
An ASEnvironmentTraitCollection has a pointer to an optional context that an ASVC is the owner of. When the ASVC is dealloc'ed, we go through all subnodes of the VC and clear out the context so that the struct isn't holding on to a garbage pointer.
Setting the traitCollection on ASCollectionNode/ASTableNode causes the cells to relayout if the trait collection changed (this is a special case for these two nodes since their cells are not actually subnodes). Setting the context to nil registered as a trait collection change and was causing a layout even as we were dealloc'ing the VC.
The logic I'm implementing here is:
If the trait collection changed AND the displayContext did not, then we should relayout.
If the trait collection changed AND the new displayContext is non-nil then we should layout
In the case where the trait collection change was caused soley by the displayContext going from non-nil to nil, then we should NOT layout.
```
// At this point we know that the two traits collections are NOT equal for some reason
BOOL needsLayout = (oldTraits.displayContext == currentTraits.displayContext) || currentTraits.displayContext != nil;
```
Is there a better place/safer way to do this?
* removed extra setNeedsLayout call
* make variable naming reflect ASEnvironmentTraitCollection vs ASTraitCollection
* move trait propagation to cell allocation instead of via a nested block
* move trait propagation when setting a displaynode's supernode instead of when adding a subnode
* fixed misspelling of "colection"
* Fixed bug in `ASEnvironmentMergeObjectAndState`
* New ASLayoutSpec methods for `setChild`/`setChildren`/`setChild:forIdentifier:` have been added to take in a trait collection.
* Added `setChild:`-like methods for ASLayoutSpecs take a traitCollection
* Fixed instances where nodes in a data controller were not getting their trait collections
* propagate traitCollection in ASDisplayNode on insertSubnode or addSubnode
Initial attempt to get display traits working with ASEnvironment.
To get proper ASDisplayTraits support, you must use an ASViewController. The ASViewController implements UITraitCollection-related methods (`traitCollectionDidChange:`, `willTransitionToTraitCollection:withTransitionCoordinator:`, viewWillTransitionToSize:withTransitionCoordinator`) to update the internal ASDisplayTraits and propagate them to subnodes.
ASTableNode and ASCollectionNode don't actually have their cells as subnodes, so a little bit of trickery is involved (on `setEnvironment:` the table/collection node gets its data controllers completedNodes and propagates the new traits. see `ASDisplayTraitsCollectionTableSetEnvironmentState`). The data controller also passes the current display traits when creating new cells.
ASViewController also supports the ability to return a custom set of display traits. So if you have a modal dialog that should always be told it is in a compact size class, you can set the override block before displaying the VC.
A new example, called Display Traits, has been added. It shows how display traits can be used in a ASViewController with a normal ASDisplayNode as its root, as well as in ASViewControllers hosting table nodes and collection nodes. There is also an example of overriding the default display traits of a VC.
Please provide feedback!
- Remove defaults for ASEnvironmentLayoutOptionsState and ASEnvironmentHierarchyState
- Add locking for ASEnvironmentLayoutExtensibilityForwarding
- Other smaller improvements
- Refactor naming of ASEnvironmentCollection to ASEnvironmentState
- Remove struct pointers
- Move ASEnvironmentStatePropagation to a enum class
- Move merge functions to pure functions
- Move ASLayoutOptionsForwarding and ASLayoutableExtensibility into ASLayoutSpec and ASDisplayNode
- Remove ASLayoutableSetValuesForLayoutable and move into explicit classes (ASDisplayNode, ASTextNode)
