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).
* Let Theme insert an IconTheme into the widget tree
* flip the order, no real reason
* Let icon theme use its own fallback
* review notes
* more review notes
Eliminate the implementation detail of which function is called to
trigger vibration on iOS, instead report the vibration constant.
Also note that not all iOS devices support haptic feedback (e.g., older
iPod touch devices).
Previously we used logical pixels. This made the accessibility metrics
tiny on modern devices, since the OS works in physical units.
Also add a bit more debugging info and some docs.
Also:
* Make TextPainter.preferredLineHeight honour root fontSize
* Remove bogus docs.
* More aggressively track dirty state for RenderEditable.
* Some tests.
If the caller doesn't explicitly give the brightness of the primary
color, we now estimate it using an algorithm from the Web Content
Accessibility Guidelines.
Also, this patch contains a function that converts RGB colors to
HSVColors. I was originally going to use that, but the WCAG algorithm
ended up seeming like a better choice. The patch still includes this
function because it's generally useful.
Fixes#5718
