Toolbar mockup

main.dart

import 'package:flutter/material.dart';

const Color darkBlue = Color.fromARGB(255, 18, 32, 47);

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      theme: ThemeData.dark().copyWith(
        scaffoldBackgroundColor: darkBlue,
      ),
      debugShowCheckedModeBanner: false,
      home: const Scaffold(
        body: Center(
          child: MyWidget(),
        ),
      ),
    );
  }
}

class MyWidget extends StatelessWidget {
  const MyWidget({super.key});

  @override
  Widget build(BuildContext context) {
    return Container(
        width: 34,
        height: 500,
        color: Colors.black54,
        padding: const EdgeInsets.all(3),
        child: Column(
          children: <Widget>[
            IconButton(
              iconSize: 25,
              splashRadius: 17,
              padding: EdgeInsets.zero,
              icon: const Icon(Icons.text_fields),
              onPressed: () {},
            ),
            IconButton(
              iconSize: 25,
              splashRadius: 17,
              padding: EdgeInsets.zero,
              icon: const Icon(Icons.rectangle),
              onPressed: () {},
            ),
            const Divider(
              height: 12,
              thickness: 2,
              indent: 1,
              endIndent: 1,
              color: Colors.grey,
            ),
            IconButton(
              icon: const Icon(Icons.build_outlined),
              iconSize: 25,
              splashRadius: 17,
              padding: EdgeInsets.zero,
              onPressed: () {},
            ),
            IconButton(
              iconSize: 25,
              splashRadius: 17,
              padding: EdgeInsets.zero,
              icon: const Icon(Icons.widgets_outlined),
              onPressed: () {},
            ),
            IconButton(
              iconSize: 25,
              splashRadius: 17,
              padding: EdgeInsets.zero,
              icon: const Icon(Icons.edit_outlined),
              onPressed: () {},
            ),
          ],
        ));
  }
}