* re-enable lint unnecessary_const

* remove trailling whitespaces

* remove unnecessary const (after merge)

This reverts commit cc1cf13e.

fuchsia_tester.dart still assumes Dart 1. Previously, it ran tests directly
from source, flutter_platform.dart automatically runs a kernel compile when
operating in Dart 2 mode, but this assumes a functional Dart SDK is available
in the artifacts directly, and fuchsia_tester.dart mocks out the artifacts
directory with an empty temp dir.

Remaining work is:
1. Get the frontend server building as a dependency on Fuchsia.
2. Patch fuchsia_tester.dart to use a valid Dart SDK and frontend server.

This also reverts migration to Dart 2 typedef syntax.

This reverts commit 6c56bb24. (#18362)
This reverts commit 3daebd05. (#18316)

Now that Dart 1 is turned off, reapplying my change to turn on the prefer_generic_function_type_aliases analysis option, and fix all the typedefs to Dart 2 preferred syntax.

Also eliminated the unused analysis_options_repo.yaml file and turned on public_member_api_docs in analysys_options.yaml.

No logic changes, just changing the typedef syntax for all typedefs, and updating analysis options.

Revert "Update typedef syntax to use Function notation and turn on lint for old notation. (#18035)" (#18041)

This reverts commit 32586020.

Fixes #18028

Just changes typedef declarations, no logic changes.

Our style guide says the k's are not necessary, and it seems like a good idea to make all the code be consistent on this.

Only naming changes to private vars: no logic changes.

This allows other code to get the same style without having to know exactly it is computed.

This attempts to apply some of what we learnt from UX studies, namely
that people wonder how to add multiple children to widget that take
one child.

Prevent header from thinking it can wrap and then overflowing.

Fix default footer string which lost its colon (localized values are fine).

Make the "rows per page" drop-down include at least one value even when the table lacks many items. (Previously it would assert if your table was too short.)

Make the footer scrollable.

Fix some todos and improve some debug output.

Tests for much of the above.

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.

Just some very minor tweaks to remove subtle LTR bias.

We use the same arrow rotation animation in RTL and LTR, but I think
that's correct. Usually, rotations are either clockwise or
anitclockwise, which are the same in RTL and LTR. We might need to check
with someone who reads an RTL language to confirm.

Fixes #11845

Also, fix asserts in TableBorder#paint to match documentation.

Fixes #12009

Fix a bunch of obvious RTL bugs from code inspection.

when describing non-nullable method arguments.

Moved everything icons related except the material icon button and the materialicon font list to widget

* enable always_require_non_null_named_parameters lint

* Update home.dart

Also fixes a small typo.

backgroundColor -> color
backgroundImage -> image
BackgroundImage -> DecorationImage

* make @immutable const

* fix build

Turns out we have many immutable classes.

Fixes #6892

I can't figure out if this is genius or a giant hack.

This lets you use DefaultTextStyle.merge and IconTheme.merge without
specifying a BuildContext. It automatically merges in at the
appropriate place in the tree using a Builder widget.

Rename State.config to State.widget
Rename State.didUpdateConfig to State.didUpdateWidget
Renamed all State subclasses' local variables named config to something else

Aggressively apply the const lint.

* add @required when there's an assert not null

* address review comments

Covers lib/ in package:flutter.

Also use the word "dropdown" consistently over "drop down".

This patch adds a basic test for the DataTable widget.

This patch replaces uses of Flexible with Expanded where we're using
FlexFit.tight. We still need to think of a better name for the
FlexFit.loose variant.

Also, improve the docs for Row, Column, Flex, and RenderFlex to be more
problem-oriented and to give a complete account of the layout algorithn.

Fixes #6960
Fixes #5169