This prevents some of our mixins from being subclassed.
Also, move mixins to using 'extends' instead of 'implements' for
future compatibility with Dart changes.
Also, rename a class that had Mixin in the name but was not a mixin.
Also, clean up the menus code a bit.
Also, make it easier to write a PopupMenuEntry that has itself many
items (for example, the way Chrome's menu has icons in a row).
The lint ensures that the prefix you use in your "import ... as"
directive conforms to lowercase_with_underscores style. However,
generated code often doesn't, since it may use preceding underscores
for collision avoidance, or directly use locale codes in the
prefixes.
Minor fixes throughout, e.g. removing trailing commas from the end of sample code expressions, changing headings to "sample code" more consistently, removing stale todos, fix typos in a private method name, minor grammar fixes, added some clarifications to CircularProgressIndicator, LinearProgressIndicator, CrossAxisAlignment, added some cross-references to various members, made it slightly clearer that layout algorithms are implementation details.
Clarified "elevation" throughout.
Added docs to InkResponse and InkWell.
Added sample code for: SliverAppBar, Card, ListTile, EdgeInsets, Row, Column, CustomScrollView, ListView, SliverFixedExtentList, and SliverGrid.
Fixes#10317.
Fixes#10316.
Fixes#10267. (sort of, see comment therein)
Fixes#9331. (sort of, see comment therein)
Fixes#9407. (sort of, see comment therein)
* Add more tests of toStringDeep.
These tests will help ensure toStringDeep behavior is not regressed
by refactoring toStringDeep to support structured data.
Makes debugging semantics easier (e.g. which RenderObject has semantics, where is a SemanticNode seen in the semantic tree comming from, etc).
It's only printed if accessibility is turned on.
* Rolls the engine to 75c74dc463d56e17be10315cfde409010fd8f90b.
* Adds framework support for the `AppLifecycleState.inactive` and `AppLifecycleState.suspending` states.
What are the new states?
------------------------
* `AppLifecycleState.inactive` is emitted on iOS only and corresponds to iOS's foreground inactive state. Current iOS state transitions are:
`resumed` <--> `inactive` <--> `paused`
* `AppLifecycleState.suspending` is currently emitted on Android only and corresponds to the
transition to Android's stopped state. Current Android state transitions are:
`resumed` <--> `paused` --> `suspending` --> `resumed`
These transitions may change in future.
This is a breaking change on iOS
--------------------------------
This changes the semantics of the `AppLifecycleState.paused` state on
iOS. The behaviour associated with this state is unchanged on Android.
For background on iOS application states see the state transition
diagram in the [App Programming Guide for iOS](https://developer.apple.com/library/content/documentation/iPhone/Conceptual/iPhoneOSProgrammingGuide/TheAppLifeCycle/TheAppLifeCycle.html#//apple_ref/doc/uid/TP40007072-CH2-SW6).
On iOS, prior to this change, `AppLifecycleState.paused` corresponded to
a transition to the _foreground inactive_ state. It now corresponds to a
transition to the _background state_. The newly-added
`AppLifecycleState.inactive` state now corresponds to entering the
_foreground inactive_ state, which (currently) has no exact analogue on
Android.
Briefly, the _foreground inactive_ state is the state entered when
switching from an app to the app switcher, receiving a phone call, or
responding to a TouchID request. Apps are permitted to continue
animating/updating views in this state if desired. From the _foreground
inactive_ state, the app may transition back to _active_ (e.g., entering
the app switcher then resuming the app), or to the _background_ state
(e.g., switching to the home screen or another app).
What to change
--------------
If your app does not handle the `AppLifecycleState.paused` state in a
`WidgetsBindingObserver.didChangeAppLifecycleState` implementation, no
changes are required.
If you do handle `AppLifecycleState.paused`, you may additionally wish
to also handle `AppLifecycleState.inactive`. For example, games should
probably pause on entering the app switcher rather than wait to be
backgrounded.
More details
------------
For background on Android application states see the state transition
diagram in the [Android Activity Lifecycle docs](https://developer.android.com/guide/components/activities/activity-lifecycle.html#alc).
