* spelling: accommodate

* spelling: allotted

* spelling: anonymous

* spelling: artificial

* spelling: associated

* spelling: asset

* spelling: button

* spelling: canvas

* spelling: compatibility

* spelling: coverage

* spelling: condition

* spelling: decoration

* spelling: deferring

* spelling: diameter

* spelling: direction

* spelling: displacement

* spelling: dropdown

* spelling: needing

* spelling: environment

* spelling: exited

* spelling: expansion

* spelling: explore

* spelling: families

* spelling: horizontal

* spelling: increment

* spelling: indices

* spelling: internationalization

* spelling: labrador

* spelling: localizations

* spelling: midflight

* spelling: milliseconds

* spelling: minimum

* spelling: multiple

* spelling: multiplication

* spelling: navigator

* spelling: overridden

* spelling: package

* spelling: performance

* spelling: platform

* spelling: porsche

* spelling: position

* spelling: preceded

* spelling: precede

* spelling: precedence

* spelling: print

* spelling: property

* spelling: readily

* spelling: reproducibility

* spelling: rounded

* spelling: scroll

* spelling: separate

* spelling: separator

* spelling: services

* spelling: specific

* spelling: specify

* spelling: synchronously

* spelling: through

* spelling: timeout

* spelling: triangle

* spelling: trivial

* spelling: unusual

* spelling: then

* spelling: vertically

* spelling: visible

* spelling: visited

* spelling: voice

* Add selection haptic feedback to Cupertino Pickers

* review

* don't haptic on android

* Fix focus switching when changing tabs in CupertinoTabScaffold

* review

* Test focuses are saved within tabs

* review

- Add override of border color of CupertinoNavigationBar
- Add background color to CupertinoPageScaffold

This updates the CupertinoAlertDialog to respect text scale factor more properly. Before this, it would scale, but would clip the action buttons at large scales, and would draw in the safe area. It also didn't match the iOS alert because the content didn't scroll. Now it does those properly.

I didn't address the fact that buttons should lay out properly (Issue #14345), but that's probably pretty low priority.

Fixes #12484

* controller, position and test

* Make controllers swappable

* WIP

* Create a ListWheelScrollPhysics

* Created picker and gallery demo and testing now

* Works. Ready to document and test.

* Document and add tests. Make the scroll controller more generic.

* minor cleanup

* review

* review

* fix tests

* stop using TransformLayers for now

* Make FadeTransition more efficient

* Update fade_transition_test.dart

* Update proxy_box.dart

to align with `SemanticsAction` and other enum-like types.

* Create CupertinoScrollbar

* handle main axis margin

* Adaptive material scrollbar and tests

* Small tweaks

* reapply changes on head

* Docs

* start

* Refactored ScrollbarPainter to be more immutable

* fix tests

* fix bug: one animationcontroller pointed to multiple painters

* some docs tweak

* remove unused import

* review

* review

* add dispose

Applies top, left, right media padding for iOS safe area insets. This is
a follow-up to the media padding applied to large titles in
flutter/flutter#13550.

Applies left and right media padding to Cupertino navigation bar large
titles.

Let translucent Cupertino bars have its scaffold children automatically pad their heights - second try (#13440)

* Let translucent Cupertino bars have its scaffold children automatically pad their heights (#13194)

* Let lists automatically add sliver padding from media query. Translucent nav and tab bars leave behind media query paddings in scaffolds.

* tests

* const lint

* Rename base abstract class to generalized ObstructingPreferredSizeWidget

* review

* More docs and comments from #13317

This allows the scheduler library to depend on the services library
and the painting library to depend on the scheduler library without
the services library having to depend on the scheduler library.

While I was at it I also cleaned up some of the binding logic: the
licenses logic can now be overridden (and the test library does so),
and the image cache can now be overridden as well.

This adjusts the CupertinoTabBar height in the presence of bottom
padding. On the iPhone X, this will increase the height to account for
the home indicator widget.

Revert "Let translucent Cupertino bars have its scaffold children automatically pad their heights (#13194)" (#13317)

This reverts commit 5c4ffa13.

* Let lists automatically add sliver padding from media query. Translucent nav and tab bars leave behind media query paddings in scaffolds.

* tests

* const lint

* Rename base abstract class to generalized ObstructingPreferredSizeWidget

Fixes the remaining known issues with widgets supporting RTL.

Previously, ExpansionPanel would do weird things if interacted with
when it was already animating. This is fixed and there's now a test.

Also:

 * Minor fixes to make the gallery work in RTL, not that there's
   any way to see that without hard-coding the framework to RTL.
   But at least I'll be less annoyed when doing that.

 * Some trivial code and documentation cleanup.

fixes #11992 

* create auto back button behaviour

* cosmetic fidelity

* tests

* review

* document new icon

libtxt has different policies than Blink for trimming whitespace.  This change
will make the test results consistent in both text renderers.

Unlike FractionalOffset, Alignment uses the center as the zero of the
coordinate system, which makes the RTL math work out much cleaner.

Also, make FractionalOffset into a subclass of Alignment so that clients
can continue to use FractionalOffset.

* Refactor CupertinoScaffold

* Rename rootTabPageBuilder to tabBuilder

* fix tab transparency padding

* add a CupertinoTab

* Add default background color

* Add a bunch of examples

* A bunch of tests

* Refactor CupertinoScaffold

* Rename rootTabPageBuilder to tabBuilder

* fix tab transparency padding

* Add default background color

* review notes

* fix test

* review

* Rename CupertinoTab to CupertinoTabView

* remove final ; in sample code for analyzer

* Refactor CupertinoScaffold

* Rename rootTabPageBuilder to tabBuilder

* fix tab transparency padding

* Add default background color

* review notes

* fix test

* Things lay out but the effects not right yet

* Remaining functionalities and tests

* one line large title only

* Add more docs

* review

Fixes #11868

* upgrade to linter-0.1.35

* re-enable lint prefer_const_constructors

* address review comments

Fixes #11358

* Introduce a Directionality inherited widget which sets the ambient LTR vs RTL mode (defaulting to null, which means you cannot use directionality-influenced values).

* Make it possible to configure Padding (including Container.padding and Container.margin) using a directionality-agnostic EdgeInsets variant.

* Provide textDirection and verticalDirection controls on Row and Column to make them RTL-aware.

* Introduce a variant of FractionalOffset based on the EdgeInsets variant. Not yet actually used.

* Fix all the tests that depended on Row defaulting to LTR.

* Properly update semantics when Material/Cupertino Slider are disabled

* whitespace fix

* fix style

* Make iOS back gesture triggerable from the edge only.

* change to positioned

* started copying stuff into cupertino page route

* extracted from material page route. Ready for testing

* works with button and gesture

* tests and docs

* review notes

* review notes