Repository: flutter
Issue:  Cannot theme `shape` independently for `SnackBar` with different `behavior`
Labels: c: new feature,framework,f: material design,c: proposal,P3,team-design,triaged-design,f: theming

## Steps to Reproduce

If you create a `SnackBarThemeData` where you define its `shape` with the intent to replicate something similar that the in default theme behavior offers, which is having different border radius for `SnackBar` with `behavior` `SnackBarBehavior.fixed` and `SnackBarBehavior.floating` you cannot do that with a SnackBar theme.

Typically you may want to keep the `fixed` behavior shape rectangular without any `Shape` added to it, while you might want to modify the `Shape` border radius of the `floating` one. The default null `shape` behavior implements this, but then you can only get the M2 default border radius of 4dp, while keeping the fixed one straight.

The `SnackBar` does things like this as part of its built in behavior when `shape` is not defined:

```dart
    final ShapeBorder? shape = widget.shape
      ?? snackBarTheme.shape
      ?? (isFloatingSnackBar 
        ? const RoundedRectangleBorder(borderRadius: BorderRadius.all(Radius.circular(4.0))) 
        : null);
```


If we define `SnackBarThemeData` for the `SnackBar`, where we assign values to `shape` we can only define a single `shape` that applies to both `behavior` types, for example:

```dart
const mySnackTheme = SnackBarThemeData(
  shape: RoundedRectangleBorder(
    borderRadius: BorderRadius.only(
      topLeft: Radius.circular(16.0),
      topRight: Radius.circular(16.0),
      bottomLeft: Radius.circular(16.0),
      bottomRight: Radius.circular(16.0),
    ),
  ),
);
```

We can not set separate `shape` theme properties that would apply only to a specific `SnackBar` `behavior`, which would be needed to replicate similar behavior styles via theming.

### Expected and Actual Results

Expected to be able to replicate similar behavior on `SnackBar` like default un-themed behavior offers for different `behavior`, but with slightly different values than the default ones, e.g. different border radius than 4 dp on `floating`, but keeping `rectangular` shape on `fixed` behavior. However, there is no way to do so, as shown below:

| Un-themed SnackBar behavior |  Themed SnackBar cannot replicate behavior styles |
| --- | --- | 
| Un-themed actual result, rectangular fixed SnackBar | Themed actual result, expect to be able to keep themed fixed SnackBar rectangular...|
| ![Screen Shot 2022-07-28 at 15 39 54](https://user-images.githubusercontent.com/39990307/181511906-6f1dcc1c-d789-4d9f-9a4f-9e07d93b1b28.png) | ![Screen Shot 2022-07-28 at 15 40 37](https://user-images.githubusercontent.com/39990307/181512340-fed92088-9092-46e3-a02e-c18093eed297.png) |
| Un-themed actual result, 4 dp border radius floating SnackBar | ...while the themed floating one uses custom border radius, eg 16 dp  |
| ![Screen Shot 2022-07-28 at 15 40 18](https://user-images.githubusercontent.com/39990307/181512017-3c35603a-b0e0-44c4-98e3-e7e3a2d956a5.png) | ![Screen Shot 2022-07-28 at 15 41 01](https://user-images.githubusercontent.com/39990307/181512396-8e6a5dc8-c9e6-4b0a-99cc-a61b9cf23ff8.png) |

## Proposal

When designing widgets and their themes, please consider not building in un-themed widget default styles and behavior that cannot be replicated when using theming.

The `SnackBar` does not yet have a Flutter M3 implementation or even a public spec on https://m3.material.io/, but presumable border radius for the `floating` behavior is going to be some other value than 4dp in M3. If so, while implementing the M3 style, also adding support for theming the current two behaviors independently of each other, may be a good opportunity.

For convenience, this sample can also be tested on DartPad here:
https://dartpad.dev/?id=a7815b94db8361f7266fc1bf650d8f66

## Related Issues

This issue is related to https://github.com/flutter/flutter/issues/107946 that also contains general discussion on theming of widget variants. This `SnackBar` themed shapes for different `behavior`, is equivalent to that issue. cc @darrenaustin 

<details>
<summary>Code sample</summary>


```dart
// MIT License
//
// Copyright (c) 2022 Mike Rydstrom
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in all
// copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
// SOFTWARE.

import 'package:flutter/material.dart';

// Light M3 ColorScheme.
const ColorScheme mySchemeLight = ColorScheme(
  brightness: Brightness.light,
  primary: Color(0xff386a20),
  onPrimary: Color(0xffffffff),
  primaryContainer: Color(0xffc0f0a4),
  onPrimaryContainer: Color(0xff042100),
  secondary: Color(0xff55624c),
  onSecondary: Color(0xffffffff),
  secondaryContainer: Color(0xffd9e7cb),
  onSecondaryContainer: Color(0xff131f0d),
  tertiary: Color(0xff386667),
  onTertiary: Color(0xffffffff),
  tertiaryContainer: Color(0xffbbebeb),
  onTertiaryContainer: Color(0xff002021),
  error: Color(0xffba1b1b),
  onError: Color(0xffffffff),
  errorContainer: Color(0xffffdad4),
  onErrorContainer: Color(0xff410001),
  outline: Color(0xff74796e),
  background: Color(0xfffdfdf6),
  onBackground: Color(0xff1a1c18),
  surface: Color(0xfffdfdf6),
  onSurface: Color(0xff1a1c18),
  surfaceVariant: Color(0xffdfe4d6),
  onSurfaceVariant: Color(0xff43493e),
  inverseSurface: Color(0xff2f312c),
  onInverseSurface: Color(0xfff1f1ea),
  inversePrimary: Color(0xff9cd67d),
  shadow: Color(0xff000000),
  surfaceTint: Color(0xff386a20),
);

// Dark M3 ColorScheme.
const ColorScheme mySchemeDark = ColorScheme(
  brightness: Brightness.dark,
  primary: Color(0xff9cd67d),
  onPrimary: Color(0xff0c3900),
  primaryContainer: Color(0xff205107),
  onPrimaryContainer: Color(0xffc0f0a4),
  secondary: Color(0xffbdcbb0),
  onSecondary: Color(0xff273420),
  secondaryContainer: Color(0xff3e4a36),
  onSecondaryContainer: Color(0xffd9e7cb),
  tertiary: Color(0xffa0cfcf),
  onTertiary: Color(0xff003738),
  tertiaryContainer: Color(0xff1e4e4e),
  onTertiaryContainer: Color(0xffbbebeb),
  error: Color(0xffffb4a9),
  onError: Color(0xff680003),
  errorContainer: Color(0xff930006),
  onErrorContainer: Color(0xffffb4a9),
  outline: Color(0xff8d9286),
  background: Color(0xff1a1c18),
  onBackground: Color(0xffe3e3dc),
  surface: Color(0xff1a1c18),
  onSurface: Color(0xffe3e3dc),
  surfaceVariant: Color(0xff43493e),
  onSurfaceVariant: Color(0xffc4c8bb),
  inverseSurface: Color(0xffe3e3dc),
  onInverseSurface: Color(0xff2f312c),
  inversePrimary: Color(0xff386a20),
  shadow: Color(0xff000000),
  surfaceTint: Color(0xff9cd67d),
);

const mySnackTheme = SnackBarThemeData(
  shape: RoundedRectangleBorder(
    borderRadius: BorderRadius.only(
      topLeft: Radius.circular(16.0),
      topRight: Radius.circular(16.0),
      bottomLeft: Radius.circular(16.0),
      bottomRight: Radius.circular(16.0),
    ),
  ),
);

// Example theme -
ThemeData demoTheme(Brightness mode, bool useMaterial3, bool useSnackTheme) =>
    mode == Brightness.light
        ? ThemeData(
            colorScheme: mySchemeLight,
            toggleableActiveColor:
                useMaterial3 ? mySchemeLight.primary : mySchemeLight.secondary,
            primaryColor: mySchemeLight.primary,
            primaryColorLight: Color.alphaBlend(
                Colors.white.withAlpha(0x66), mySchemeLight.primary),
            primaryColorDark: Color.alphaBlend(
                Colors.black.withAlpha(0x66), mySchemeLight.primary),
            secondaryHeaderColor: Color.alphaBlend(
                Colors.white.withAlpha(0xCC), mySchemeLight.primary),
            scaffoldBackgroundColor: mySchemeLight.background,
            canvasColor: mySchemeLight.background,
            backgroundColor: mySchemeLight.background,
            cardColor: mySchemeLight.surface,
            bottomAppBarColor: mySchemeLight.surface,
            dialogBackgroundColor: mySchemeLight.surface,
            indicatorColor: mySchemeLight.onPrimary,
            dividerColor: mySchemeLight.onSurface.withOpacity(0.12),
            errorColor: mySchemeLight.error,
            applyElevationOverlayColor: false,
            useMaterial3: useMaterial3,
            visualDensity: VisualDensity.standard,
            // Assign the SnackBar demo theme
            snackBarTheme: useSnackTheme ? mySnackTheme : null,
          )
        : ThemeData(
            colorScheme: mySchemeDark,
            toggleableActiveColor:
                useMaterial3 ? mySchemeDark.primary : mySchemeDark.secondary,
            primaryColor: mySchemeDark.primary,
            primaryColorLight: Color.alphaBlend(
                Colors.white.withAlpha(0x59), mySchemeDark.primary),
            primaryColorDark: Color.alphaBlend(
                Colors.black.withAlpha(0x72), mySchemeDark.primary),
            secondaryHeaderColor: Color.alphaBlend(
                Colors.black.withAlpha(0x99), mySchemeDark.primary),
            scaffoldBackgroundColor: mySchemeDark.background,
            canvasColor: mySchemeDark.background,
            backgroundColor: mySchemeDark.background,
            cardColor: mySchemeDark.surface,
            bottomAppBarColor: mySchemeDark.surface,
            dialogBackgroundColor: mySchemeDark.surface,
            indicatorColor: mySchemeDark.onBackground,
            dividerColor: mySchemeDark.onSurface.withOpacity(0.12),
            errorColor: mySchemeDark.error,
            applyElevationOverlayColor: true,
            useMaterial3: useMaterial3,
            visualDensity: VisualDensity.standard,
            // Assign the SnackBar demo theme
            snackBarTheme: useSnackTheme ? mySnackTheme : null,
          );

void main() {
  runApp(const IssueDemoApp());
}

class IssueDemoApp extends StatefulWidget {
  const IssueDemoApp({super.key});

  @override
  State<IssueDemoApp> createState() => _IssueDemoAppState();
}

class _IssueDemoAppState extends State<IssueDemoApp> {
  bool useMaterial3 = false;
  bool useSnackTheme = true;
  ThemeMode themeMode = ThemeMode.light;

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      debugShowCheckedModeBanner: false,
      themeMode: themeMode,
      theme: demoTheme(Brightness.light, useMaterial3, useSnackTheme),
      darkTheme: demoTheme(Brightness.dark, useMaterial3, useSnackTheme),
      home: Scaffold(
        appBar: AppBar(
          title: const Text(('SnackBar Theme Issue')),
          actions: [
            IconButton(
              icon: useSnackTheme
                  ? const Icon(Icons.circle)
                  : const Icon(Icons.circle_outlined),
              onPressed: () {
                setState(() {
                  useSnackTheme = !useSnackTheme;
                });
              },
              tooltip: "Toggle SnackBar theme ${useSnackTheme ? 'OFF' : 'ON'}",
            ),
            IconButton(
              icon: useMaterial3
                  ? const Icon(Icons.filter_3)
                  : const Icon(Icons.filter_2),
              onPressed: () {
                setState(() {
                  useMaterial3 = !useMaterial3;
                });
              },
              tooltip: "Switch to Material ${useMaterial3 ? 2 : 3}",
            ),
            IconButton(
              icon: themeMode == ThemeMode.dark
                  ? const Icon(Icons.wb_sunny_outlined)
                  : const Icon(Icons.wb_sunny),
              onPressed: () {
                setState(() {
                  if (themeMode == ThemeMode.light) {
                    themeMode = ThemeMode.dark;
                  } else {
                    themeMode = ThemeMode.light;
                  }
                });
              },
              tooltip: "Toggle brightness",
            ),
          ],
        ),
        body: HomePage(useSnackTheme: useSnackTheme),
        drawer: const Drawer(),
      ),
    );
  }
}

class HomePage extends StatelessWidget {
  const HomePage({super.key, required this.useSnackTheme});
  final bool useSnackTheme;

  @override
  Widget build(BuildContext context) {
    final String materialType =
        Theme.of(context).useMaterial3 ? 'Material 3' : 'Material 2';
    final String shapeInfo =
        useSnackTheme ? '(Shape themed)' : '(No Shape theme)';
    return ListView(
      padding: const EdgeInsets.symmetric(horizontal: 16),
      children: [
        const SizedBox(height: 8),
        Text(
          'Theme is $materialType',
          style: Theme.of(context).textTheme.titleLarge,
        ),
        const Divider(),
        const ShowColorSchemeColors(),
        const Divider(),
        const ShowThemeDataColors(),
        const Divider(),
        if (useSnackTheme)
          const Text(
              'Cannot theme Shape differently for SnackBars with different behavior'),
        if (!useSnackTheme)
          const Text(
              'Using no shape in theme has different Shape for SnackBar with different behavior'),
        const SizedBox(height: 8),
        OutlinedButton(
          onPressed: () {
            final snackBar = SnackBar(
              behavior: SnackBarBehavior.fixed,
              content: const Text('Yay! A FIXED SnackBar!'),
              action: SnackBarAction(
                label: 'Foo',
                onPressed: () {},
              ),
            );
            ScaffoldMessenger.of(context).showSnackBar(snackBar);
          },
          child: Text('Show fixed behavior SnackBar $shapeInfo'),
        ),
        const SizedBox(height: 8),
        OutlinedButton(
          onPressed: () {
            final snackBar = SnackBar(
              behavior: SnackBarBehavior.floating,
              content: const Text('Yay! A FLOATING SnackBar!'),
              action: SnackBarAction(
                label: 'Bar',
                onPressed: () {},
              ),
            );
            ScaffoldMessenger.of(context).showSnackBar(snackBar);
          },
          child: Text('Show floating behavior SnackBar $shapeInfo'),
        ),
        const Divider(),
      ],
    );
  }
}

/// Draw a number of boxes showing the colors of key theme color properties
/// in the ColorScheme of the inherited ThemeData and its color properties.
class ShowColorSchemeColors extends StatelessWidget {
  const ShowColorSchemeColors({super.key, this.onBackgroundColor});

  /// The color of the background the color widget are being drawn on.
  ///
  /// Some of the theme colors may have semi transparent fill color. To compute
  /// a legible text color for the sum when it shown on a background color, we
  /// need to alpha merge it with background and we need the exact background
  /// color it is drawn on for that. If not passed in from parent, it is
  /// assumed to be drawn on card color, which usually is close enough.
  final Color? onBackgroundColor;

  // Return true if the color is light, meaning it needs dark text for contrast.
  static bool _isLight(final Color color) =>
      ThemeData.estimateBrightnessForColor(color) == Brightness.light;

  // Return true if the color is dark, meaning it needs light text for contrast.
  static bool _isDark(final Color color) =>
      ThemeData.estimateBrightnessForColor(color) == Brightness.dark;

  // On color used when a theme color property does not have a theme onColor.
  static Color _onColor(final Color color, final Color bg) =>
      _isLight(Color.alphaBlend(color, bg)) ? Colors.black : Colors.white;

  @override
  Widget build(BuildContext context) {
    final ThemeData theme = Theme.of(context);
    final ColorScheme colorScheme = theme.colorScheme;
    final bool isDark = colorScheme.brightness == Brightness.dark;
    final bool useMaterial3 = theme.useMaterial3;

    // Grab the card border from the theme card shape
    ShapeBorder? border = theme.cardTheme.shape;
    // If we had one, copy in a border side to it.
    if (border is RoundedRectangleBorder) {
      border = border.copyWith(
        side: BorderSide(
          color: theme.dividerColor,
          width: 1,
        ),
      );
      // If
    } else {
      // If border was null, make one matching Card default, but with border
      // side, if it was not null, we leave it as it was.
      border ??= RoundedRectangleBorder(
        borderRadius: BorderRadius.all(Radius.circular(useMaterial3 ? 12 : 4)),
        side: BorderSide(
          color: theme.dividerColor,
          width: 1,
        ),
      );
    }

    // Get effective background color.
    final Color background =
        onBackgroundColor ?? theme.cardTheme.color ?? theme.cardColor;

    // Warning label for scaffold background when it uses to much blend.
    final String surfaceTooHigh = isDark
        ? _isLight(theme.colorScheme.surface)
            ? '\nTOO HIGH'
            : ''
        : _isDark(theme.colorScheme.surface)
            ? '\nTOO HIGH'
            : '';

    // Warning label for scaffold background when it uses to much blend.
    final String backTooHigh = isDark
        ? _isLight(theme.colorScheme.background)
            ? '\nTOO HIGH'
            : ''
        : _isDark(theme.colorScheme.background)
            ? '\nTOO HIGH'
            : '';

    // Wrap this widget branch in a custom theme where card has a border outline
    // if it did not have one, but retains in ambient themed border radius.
    return Theme(
      data: Theme.of(context).copyWith(
        cardTheme: CardTheme.of(context).copyWith(
          elevation: 0,
          shape: border,
        ),
      ),
      child: Column(
        crossAxisAlignment: CrossAxisAlignment.start,
        children: <Widget>[
          Padding(
            padding: const EdgeInsets.symmetric(vertical: 8),
            child: Text(
              'ColorScheme Colors',
              style: theme.textTheme.titleMedium,
            ),
          ),
          Wrap(
            alignment: WrapAlignment.start,
            crossAxisAlignment: WrapCrossAlignment.center,
            spacing: 6,
            runSpacing: 6,
            children: <Widget>[
              ColorCard(
                label: 'Primary',
                color: colorScheme.primary,
                textColor: colorScheme.onPrimary,
              ),
              ColorCard(
                label: 'on\nPrimary',
                color: colorScheme.onPrimary,
                textColor: colorScheme.primary,
              ),
              ColorCard(
                label: 'Primary\nContainer',
                color: colorScheme.primaryContainer,
                textColor: colorScheme.onPrimaryContainer,
              ),
              ColorCard(
                label: 'onPrimary\nContainer',
                color: colorScheme.onPrimaryContainer,
                textColor: colorScheme.primaryContainer,
              ),
              ColorCard(
                label: 'Secondary',
                color: colorScheme.secondary,
                textColor: colorScheme.onSecondary,
              ),
              ColorCard(
                label: 'on\nSecondary',
                color: colorScheme.onSecondary,
                textColor: colorScheme.secondary,
              ),
              ColorCard(
                label: 'Secondary\nContainer',
                color: colorScheme.secondaryContainer,
                textColor: colorScheme.onSecondaryContainer,
              ),
              ColorCard(
                label: 'on\nSecondary\nContainer',
                color: colorScheme.onSecondaryContainer,
                textColor: colorScheme.secondaryContainer,
              ),
              ColorCard(
                label: 'Tertiary',
                color: colorScheme.tertiary,
                textColor: colorScheme.onTertiary,
              ),
              ColorCard(
                label: 'on\nTertiary',
                color: colorScheme.onTertiary,
                textColor: colorScheme.tertiary,
              ),
              ColorCard(
                label: 'Tertiary\nContainer',
                color: colorScheme.tertiaryContainer,
                textColor: colorScheme.onTertiaryContainer,
              ),
              ColorCard(
                label: 'on\nTertiary\nContainer',
                color: colorScheme.onTertiaryContainer,
                textColor: colorScheme.tertiaryContainer,
              ),
              ColorCard(
                label: 'Error',
                color: colorScheme.error,
                textColor: colorScheme.onError,
              ),
              ColorCard(
                label: 'on\nError',
                color: colorScheme.onError,
                textColor: colorScheme.error,
              ),
              ColorCard(
                label: 'Error\nContainer',
                color: colorScheme.errorContainer,
                textColor: colorScheme.onErrorContainer,
              ),
              ColorCard(
                label: 'onError\nContainer',
                color: colorScheme.onErrorContainer,
                textColor: colorScheme.errorContainer,
              ),
              ColorCard(
                label: 'Background$backTooHigh',
                color: colorScheme.background,
                textColor: colorScheme.onBackground,
              ),
              ColorCard(
                label: 'on\nBackground',
                color: colorScheme.onBackground,
                textColor: colorScheme.background,
              ),
              ColorCard(
                label: 'Surface$surfaceTooHigh',
                color: colorScheme.surface,
                textColor: colorScheme.onSurface,
              ),
              ColorCard(
                label: 'on\nSurface',
                color: colorScheme.onSurface,
                textColor: colorScheme.surface,
              ),
              ColorCard(
                label: 'Surface\nVariant',
                color: colorScheme.surfaceVariant,
                textColor: colorScheme.onSurfaceVariant,
              ),
              ColorCard(
                label: 'onSurface\nVariant',
                color: colorScheme.onSurfaceVariant,
                textColor: colorScheme.surfaceVariant,
              ),
              ColorCard(
                label: 'Outline',
                color: colorScheme.outline,
                textColor: colorScheme.background,
              ),
              ColorCard(
                label: 'Shadow',
                color: colorScheme.shadow,
                textColor: _onColor(colorScheme.shadow, background),
              ),
              ColorCard(
                label: 'Inverse\nSurface',
                color: colorScheme.inverseSurface,
                textColor: colorScheme.onInverseSurface,
              ),
              ColorCard(
                label: 'onInverse\nSurface',
                color: colorScheme.onInverseSurface,
                textColor: colorScheme.inverseSurface,
              ),
              ColorCard(
                label: 'Inverse\nPrimary',
                color: colorScheme.inversePrimary,
                textColor: colorScheme.primary,
              ),
              ColorCard(
                label: 'Surface\nTint',
                color: colorScheme.surfaceTint,
                textColor: colorScheme.onPrimary,
              ),
            ],
          ),
        ],
      ),
    );
  }
}

/// Draw a number of boxes showing the colors of key theme color properties
/// in the ColorScheme of the inherited ThemeData and some of its key color
/// properties.
class ShowThemeDataColors extends StatelessWidget {
  const ShowThemeDataColors({
    super.key,
    this.onBackgroundColor,
  });

  /// The color of the background the color widget are being drawn on.
  ///
  /// Some of the theme colors may have semi-transparent fill color. To compute
  /// a legible text color for the sum when it shown on a background color, we
  /// need to alpha merge it with background and we need the exact background
  /// color it is drawn on for that. If not passed in from parent, it is
  /// assumed to be drawn on card color, which usually is close enough.
  final Color? onBackgroundColor;

  // Return true if the color is light, meaning it needs dark text for contrast.
  static bool _isLight(final Color color) =>
      ThemeData.estimateBrightnessForColor(color) == Brightness.light;

  // Return true if the color is dark, meaning it needs light text for contrast.
  static bool _isDark(final Color color) =>
      ThemeData.estimateBrightnessForColor(color) == Brightness.dark;

  // On color used when a theme color property does not have a theme onColor.
  static Color _onColor(final Color color, final Color background) =>
      _isLight(Color.alphaBlend(color, background))
          ? Colors.black
          : Colors.white;

  @override
  Widget build(BuildContext context) {
    final ThemeData theme = Theme.of(context);
    final ColorScheme colorScheme = theme.colorScheme;
    final bool isDark = colorScheme.brightness == Brightness.dark;
    final bool useMaterial3 = theme.useMaterial3;

    // Grab the card border from the theme card shape
    ShapeBorder? border = theme.cardTheme.shape;
    // If we had one, copy in a border side to it.
    if (border is RoundedRectangleBorder) {
      border = border.copyWith(
        side: BorderSide(
          color: theme.dividerColor,
          width: 1,
        ),
      );
    } else {
      // If border was null, make one matching Card default, but with border
      // side, if it was not null, we leave it as it was.
      border ??= RoundedRectangleBorder(
        borderRadius: BorderRadius.all(Radius.circular(useMaterial3 ? 12 : 4)),
        side: BorderSide(
          color: theme.dividerColor,
          width: 1,
        ),
      );
    }

    // Get effective background color.
    final Color background =
        onBackgroundColor ?? theme.cardTheme.color ?? theme.cardColor;

    // Warning label for scaffold background when it uses to much blend.
    final String scaffoldTooHigh = isDark
        ? _isLight(theme.scaffoldBackgroundColor)
            ? '\nTOO HIGH'
            : ''
        : _isDark(theme.scaffoldBackgroundColor)
            ? '\nTOO HIGH'
            : '';
    // Warning label for scaffold background when it uses to much blend.
    final String surfaceTooHigh = isDark
        ? _isLight(theme.colorScheme.surface)
            ? '\nTOO HIGH'
            : ''
        : _isDark(theme.colorScheme.surface)
            ? '\nTOO HIGH'
            : '';

    // Warning label for scaffold background when it uses to much blend.
    final String backTooHigh = isDark
        ? _isLight(theme.colorScheme.background)
            ? '\nTOO HIGH'
            : ''
        : _isDark(theme.colorScheme.background)
            ? '\nTOO HIGH'
            : '';

    // Wrap this widget branch in a custom theme where card has a border outline
    // if it did not have one, but retains in ambient themed border radius.
    return Theme(
      data: Theme.of(context).copyWith(
        cardTheme: CardTheme.of(context).copyWith(
          elevation: 0,
          shape: border,
        ),
      ),
      child: Column(
        crossAxisAlignment: CrossAxisAlignment.start,
        children: <Widget>[
          Padding(
            padding: const EdgeInsets.only(top: 8),
            child: Text(
              'ThemeData Colors',
              style: theme.textTheme.titleMedium,
            ),
          ),
          const SizedBox(height: 8),
          Wrap(
            spacing: 6,
            runSpacing: 6,
            crossAxisAlignment: WrapCrossAlignment.center,
            children: <Widget>[
              ColorCard(
                label: 'Primary\nColor',
                color: theme.primaryColor,
                textColor: _onColor(theme.primaryColor, background),
              ),
              ColorCard(
                label: 'Primary\nDark',
                color: theme.primaryColorDark,
                textColor: _onColor(theme.primaryColorDark, background),
              ),
              ColorCard(
                label: 'Primary\nLight',
                color: theme.primaryColorLight,
                textColor: _onColor(theme.primaryColorLight, background),
              ),
              ColorCard(
                label: 'Secondary\nHeader',
                color: theme.secondaryHeaderColor,
                textColor: _onColor(theme.secondaryHeaderColor, background),
              ),
              ColorCard(
                label: 'Toggleable\nActive',
                color: theme.toggleableActiveColor,
                textColor: _onColor(theme.toggleableActiveColor, background),
              ),
              ColorCard(
                label: 'Bottom\nAppBar',
                color: theme.bottomAppBarColor,
                textColor: _onColor(theme.bottomAppBarColor, background),
              ),
              ColorCard(
                label: 'Error\nColor',
                color: theme.errorColor,
                textColor: colorScheme.onError,
              ),
              ColorCard(
                label: 'Canvas$backTooHigh',
                color: theme.canvasColor,
                textColor: _onColor(theme.canvasColor, background),
              ),
              ColorCard(
                label: 'Card$surfaceTooHigh',
                color: theme.cardColor,
                textColor: _onColor(theme.cardColor, background),
              ),
              ColorCard(
                label: 'Scaffold\nBackground$scaffoldTooHigh',
                color: theme.scaffoldBackgroundColor,
                textColor: _onColor(theme.scaffoldBackgroundColor, background),
              ),
              ColorCard(
                label: 'Dialog',
                color: theme.dialogBackgroundColor,
                textColor: _onColor(theme.dialogBackgroundColor, background),
              ),
              ColorCard(
                label: 'Indicator\nColor',
                color: theme.indicatorColor,
                textColor: _onColor(theme.indicatorColor, background),
              ),
              ColorCard(
                label: 'Divider\nColor',
                color: theme.dividerColor,
                textColor: _onColor(theme.dividerColor, background),
              ),
              ColorCard(
                label: 'Disabled\nColor',
                color: theme.disabledColor,
                textColor: _onColor(theme.disabledColor, background),
              ),
              ColorCard(
                label: 'Hover\nColor',
                color: theme.hoverColor,
                textColor: _onColor(theme.hoverColor, background),
              ),
              ColorCard(
                label: 'Focus\nColor',
                color: theme.focusColor,
                textColor: _onColor(theme.focusColor, background),
              ),
              ColorCard(
                label: 'Highlight\nColor',
                color: theme.highlightColor,
                textColor: _onColor(theme.highlightColor, background),
              ),
              ColorCard(
                label: 'Splash\nColor',
                color: theme.splashColor,
                textColor: _onColor(theme.splashColor, background),
              ),
              ColorCard(
                label: 'Shadow\nColor',
                color: theme.shadowColor,
                textColor: _onColor(theme.shadowColor, background),
              ),
              ColorCard(
                label: 'Hint\nColor',
                color: theme.hintColor,
                textColor: _onColor(theme.hintColor, background),
              ),
              ColorCard(
                label: 'Selected\nRow',
                color: theme.selectedRowColor,
                textColor: _onColor(theme.selectedRowColor, background),
              ),
              ColorCard(
                label: 'Unselected\nWidget',
                color: theme.unselectedWidgetColor,
                textColor: _onColor(theme.unselectedWidgetColor, background),
              ),
            ],
          ),
        ],
      ),
    );
  }
}

class ColorCard extends StatelessWidget {
  const ColorCard({
    super.key,
    required this.label,
    required this.color,
    required this.textColor,
    this.size,
  });

  final String label;
  final Color color;
  final Color textColor;
  final Size? size;

  @override
  Widget build(BuildContext context) {
    return SizedBox(
      width: 86,
      height: 58,
      child: Card(
        margin: EdgeInsets.zero,
        clipBehavior: Clip.antiAlias,
        color: color,
        child: Center(
          child: Text(
            label,
            style: TextStyle(color: textColor, fontSize: 11),
            textAlign: TextAlign.center,
          ),
        ),
      ),
    );
  }
}


```

</details>

<details>
  <summary>Flutter Doctor</summary>

```
flutter doctor -v
[✓] Flutter (Channel master, 3.1.0-0.0.pre.1937, on macOS 12.4 21F79 darwin-arm, locale en-US)
    • Flutter version 3.1.0-0.0.pre.1937 on channel master at /Users/rydmike/fvm/versions/master
    • Upstream repository https://github.com/flutter/flutter.git
    • Framework revision dd4154bf4d (56 minutes ago), 2022-07-28 20:31:05 +0800
    • Engine revision db34a63162
    • Dart version 2.19.0 (build 2.19.0-43.0.dev)
    • DevTools version 2.15.0

[✓] Android toolchain - develop for Android devices (Android SDK version 32.1.0-rc1)
    • Android SDK at /Users/rydmike/Library/Android/sdk
    • Platform android-32, build-tools 32.1.0-rc1
    • Java binary at: /Applications/Android Studio.app/Contents/jre/Contents/Home/bin/java
    • Java version OpenJDK Runtime Environment (build 11.0.12+0-b1504.28-7817840)
    • All Android licenses accepted.

[✓] Xcode - develop for iOS and macOS (Xcode 13.4)
    • Xcode at /Applications/Xcode.app/Contents/Developer
    • Build 13F17a
    • CocoaPods version 1.11.3

[✓] Chrome - develop for the web
    • Chrome at /Applications/Google Chrome.app/Contents/MacOS/Google Chrome

[✓] Android Studio (version 2021.2)
    • Android Studio at /Applications/Android Studio.app/Contents
    • Flutter plugin can be installed from:
      🔨 https://plugins.jetbrains.com/plugin/9212-flutter
    • Dart plugin can be installed from:
      🔨 https://plugins.jetbrains.com/plugin/6351-dart
    • Java version OpenJDK Runtime Environment (build 11.0.12+0-b1504.28-7817840)

[✓] IntelliJ IDEA Community Edition (version 2022.1.1)
    • IntelliJ at /Applications/IntelliJ IDEA CE.app
    • Flutter plugin version 67.1.4
    • Dart plugin version 221.5591.58

[✓] VS Code (version 1.69.2)
    • VS Code at /Applications/Visual Studio Code.app/Contents
    • Flutter extension version 3.44.0

[✓] Connected device (2 available)
    • macOS (desktop) • macos  • darwin-arm64   • macOS 12.4 21F79 darwin-arm
    • Chrome (web)    • chrome • web-javascript • Google Chrome 103.0.5060.134

[✓] HTTP Host Availability
    • All required HTTP hosts are available

• No issues found!



```

</details>