This fixes https://github.com/flutter/flutter/issues/20746

It was causing problems rolling Flutter into Fuchsia

* re-enable lint unnecessary_const

* remove trailling whitespaces

* remove unnecessary const (after merge)

This reverts commit cc1cf13e.

This reverts commit 989f5741.

This optimizes the AnimatedSwitcher so that it tags the right widget with its keyed subtree, and avoids rebuilding the transition unnecessarily.

This significantly improves the performance of Chips (which uses AnimatedSwitcher to swap out it's avatar and delete icon children).

We don't really like the name AnimatedChildSwitcher, and we think that AnimatedSwitcher might be better (since the Child part is redundant). We also considered AnimatedChild, AnimatedTransition and AnimatedReplacement (among others).

Nothing in here besides a rename.

This converts the chips to use a ChipThemeData to get most of their customization values from (if not overridden by specific arguments to the chip constructors), and to have the base ThemeData contain one of these. It also adds the ChipTheme widget that will allow overriding the theme for a particular subtree in the widget hierarchy.

Added tests for both, and just more tests in general for the Chips.

There was a bug in the size calculation for the height of the chip label, where it would force the label to be larger than it wanted to be, causing text to not be vertically centered.

This renames the chip's border attribute to 'shape' so that it is consistent with the other places where we supply a ShapeBorder.

This is a breaking change, but a very small one: the border attribute was introduced only a few months ago, and is not widely used.

This implements various different chip types: There are now the InputChip, ChoiceChip, FilterChip, ActionChip, and the original vanilla Chip, all of which have different uses. They can be customized in a number of ways. See their docs for more information.

Also fixes #16083

This updates the visual look of the Chip class, so that it scales properly in the face of text scale (and label widget size) changes, and bases its height off of the label widget's height, constraining the other widgets it contains to be the same height.

To do this properly, I had to implement a custom render object that will measure the height of the label, so the guts of this class are basically rewritten.

In addition, to allow the circle avatar to increase in size when the chip does, I added minRadius and maxRadius arguments to it, and I updated its color handling to use the light/dark primary colors of the theme in a smart way instead of just using black and white.

Updated and added tests.

...and document what I did.

In order to allow chips to be properly drawn when they expand in size (without
using IntrinsicHeight), I needed a BoxDecoration shape that would be dependent
upon the rendered height of the widget. This seemed to be pretty generally
useful, so I added a new ShapeDecoration called StadiumBorder. It uses the
minimum dimension to adjust the BorderRadius of a rounded rect in the shape
decoration.

I also converted some uses of BoxShape to be case statements, updated the
chips to use the StadiumBorder decoration, and updated some of the metrics to match
the Material spec, as well as implementing lerping to and from StadiumBorder.

* 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.

* Wrap the label widget of the Chip in a Flexible. (#11523)

* This allows the Chip to constrain the size of its content after taking into account the space occupied by the avatar and delete icon (if they are present)

* Adding unit tests to evaluate correct size constraints of the Chip widget's label. (#11523)

* Minor change in formatting.

* Adjust function formatting.

* Adds more customization options to the Chip widget

Includes:
- Custom Tooltip message for the delete button;
- Custom background color for the chip
- Custom delete icon color
- Custom label text style

* Adds missing type annotations to tests and improves documentation.

* Tweaks labelStyle field documentation

* Provide haptic/acoustic feedback for tap & long-press on Android

* review comments

* fixed example code

* review comments

* comment fix

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

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

* use color.shadeXxx instead of color[Xxx]

* remove calls to .shade500 on MaterialColor

* remove calls to .shade200 on MaterialAccentColor

* fix test

Covers lib/ in package:flutter.

* Added custom radii to RRect.

This is the first commit towads an implementation of
MergeableMaterial. It adds custom radii to RRect.

* Renamed RRect constructors and added BorderRadius.

BorderRadius is a class similar to EdgeInsets that lets you define
all rounded corners of a rounded rectangle easily.

Anywhere that accepted IconData now accepts either an Icon or an
ImageIcon.

Places that used to take an IconData in an `icon` argument, notably
IconButton and DrawerItem, now take a Widget in that slot. You can wrap
the value that used to be passed in in an Icon constructor to get the
same result.

Icon itself now takes the icon as a positional argument, for brevity.

ThemeData now has an iconTheme as well as a primaryIconTheme, the same
way it has had a textTheme and primaryTextTheme for a while.

IconTheme.of() always returns a value now (though that value itself may
have nulls in it). It defaults to the ThemeData.iconTheme.

IconThemeData.fallback() is a new method that returns an icon theme data
structure with all fields filled in.

IconTheme.merge() is a new constructor that takes a context and creates
a widget that mixes in the new values with the inherited values.

Most places that introduced an IconTheme widget now use IconTheme.merge.

IconThemeData.merge and IconThemeData.copyWith act in a way analogous to
the similarly-named members of TextStyle.

ImageIcon is introduced. It acts like Icon but takes an ImageProvider
instead of an IconData.

Also: Fix the analyzer to actually check the stocks app.

This reverts commit 55f9145e.

Turns out that this commit breaks apps that use the material library,
because of the _errorTextStyle DefaultTextStyle which has inherit:true.
Just setting it to false doesn't work, unfortunately, because then you
hit some sort of issue with merging that text style with others that
have inherit:true.

To make it clear that this constructor requires an explicit style. Also
throw a descriptive error recommending the inherit constructor for
styles with the inherit bit set.

Fixes #3842