Summary:
This adds support for the concept of visibility depth.
Visibility essentially defines the number of user actions it would
take a user to have a view controller visible. Knowing a view controllers
visibility depth allows view controllers to take action such as clearing
out memory that can be restored at a later date.
This patch also add two new view controller subclasses which adopt
the ASManagesChildVisibilityDepth protocol. Any view controller
that has child view controllers can adopt this protocol to indicate
to the child what they're visibility is. For example, ASNavigationController
will return a visibility depth of it's own visibilityDepth + 1 for
a view controller that would be revealed by tapping the back button.
Move common implementations to macros
Turn off visibility logging
Differential Revision: https://phabricator.pinadmin.com/D90395
This adds support for the concept of visibility depth.
Visibility essentially defines the number of user actions it would
take a user to have a view controller visible. Knowing a view controllers
visibility depth allows view controllers to take action such as clearing
out memory that can be restored at a later date.
This patch also add two new view controller subclasses which adopt
the ASManagesChildVisibilityDepth protocol. Any view controller
that has child view controllers can adopt this protocol to indicate
to the child what they're visibility is. For example, ASNavigationController
will return a visibility depth of it's own visibilityDepth + 1 for
a view controller that would be revealed by tapping the back button.
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.
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