An alternative to the extension method system for styling widgets without excessive nesting.

container_widget.dart

import 'package:flutter/material.dart';

abstract class StatelessContainerWidget extends StatelessWidget {
  /// A constructor that exposes all of the `Container` arguments as a style
  /// object.
  const StatelessContainerWidget({
    super.key,
    this.cStyle,
  });

  final ContainerStyle? cStyle;

  /// Build wraps the child in a container.
  @override
  Widget build(BuildContext context) {
    if (cStyle == null) {
      return buildTwoElectricBoogaloo(context);
    }
    return Container(
      alignment: cStyle!.alignment,
      padding: cStyle!.padding,
      color: cStyle!.color,
      decoration: cStyle!.decoration,
      foregroundDecoration: cStyle!.foregroundDecoration,
      width: cStyle!.width,
      height: cStyle!.height,
      constraints: cStyle!.constraints,
      margin: cStyle!.margin,
      transform: cStyle!.transform,
      transformAlignment: cStyle!.transformAlignment,
      clipBehavior: cStyle!.clipBehavior,
      child: Builder(builder: (context) => buildTwoElectricBoogaloo(context)),
    );
  }

  /// Override this instead of [build].
  Widget buildTwoElectricBoogaloo(BuildContext context);
}

class ContainerStyle {
  const ContainerStyle({
    this.alignment,
    this.padding,
    this.color,
    this.decoration,
    this.foregroundDecoration,
    this.width,
    this.height,
    this.constraints,
    this.margin,
    this.transform,
    this.transformAlignment,
    this.clipBehavior = Clip.none,
  });

  final AlignmentGeometry? alignment;
  final EdgeInsets? padding;
  final Color? color;
  final BoxDecoration? decoration;
  final BoxDecoration? foregroundDecoration;
  final BoxConstraints? constraints;
  final EdgeInsetsGeometry? margin;
  final Matrix4? transform;
  final AlignmentGeometry? transformAlignment;
  final Clip clipBehavior;
  final double? width;
  final double? height;
}

class MyWidget extends StatelessContainerWidget {
  const MyWidget({
    super.key,
    super.cStyle,
  });

  @override
  Widget buildTwoElectricBoogaloo(BuildContext context) {
    return const Column(
      children: [
        CStyleText(
          'this is padded',
          cStyle: ContainerStyle(
            padding: EdgeInsets.all(8),
          ),
        ),
        CStyleText(
          'this is padded with a blue background',
          cStyle: ContainerStyle(
            color: Colors.blue,
            padding: EdgeInsets.all(8),
          ),
        ),
        CStyleText(
          'this avoids the nesting of Container while remaining Flutter '
          'idiomatic.',
          cStyle: ContainerStyle(
            color: Colors.red,
            padding: EdgeInsets.all(8),
            margin: EdgeInsets.only(top: 4),
            width: 200,
            height: 200,
          ),
        ),
      ],
    );
  }
}

class CStyleText extends StatelessContainerWidget {
  const CStyleText(
    this.text, {
    super.key,
    super.cStyle,
  });

  final String text;

  @override
  Widget buildTwoElectricBoogaloo(BuildContext context) {
    return Text(text);
  }
}