ListView.builder

import 'package:flutter/material.dart';

final Color backgroundColor = Color(0xFF242E42);

class Sidebar extends StatelessWidget {
  String    itemText;
  IconData  itemIcon;

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Stack(
        children: <Widget>[
          menu(context),
        ],
      ),
    );
  }

  Widget menu(context) {
    Size size = MediaQuery.of(context).size;

    double screenWidth  = size.width;
    double screenHeight = size.height;

    return Container(
      color : backgroundColor,
      child: Column(
        mainAxisSize        : MainAxisSize.max,
        crossAxisAlignment  : CrossAxisAlignment.start,
        mainAxisAlignment   : MainAxisAlignment.start,
        children: <Widget>[
          Padding(
            padding: const EdgeInsets.only(left: 8, right: 0, top: 55, bottom: 35),
            child: Image.asset(
              'images/logo.png',
              width : 20.0,
              height: 20.0,
              fit   : BoxFit.contain
            ),
          ),
          DisplayListView(),
        ],
      )
    );
  }
}

class ListViewModel {
  final String    itemText;
  final IconData  itemIcon;

  ListViewModel({
    this.itemText,
    this.itemIcon
  });
}

List listViewData = [
  ListViewModel(
    itemText: "Dashboard",
    itemIcon: Icons.dashboard,
  ),
  ListViewModel(
    itemText: "Profile",
    itemIcon: Icons.account_circle,
  ),
  ListViewModel(
    itemText: "Messages",
    itemIcon: Icons.message,
  ),
  ListViewModel(
    itemText: "Friends",
    itemIcon: Icons.supervisor_account,
  ),
  ListViewModel(
    itemText: "Branches",
    itemIcon: Icons.account_circle,
  ),
  ListViewModel(
    itemText: "Collapse",
    itemIcon: Icons.arrow_forward_ios,
  ),
];

class DisplayListView extends StatefulWidget {
  @override
  _DisplayListViewState createState() => _DisplayListViewState();
}

class _DisplayListViewState extends State {
  bool isCollapsed = true;

  @override
  Widget build(BuildContext context) {
    return ListView.builder(
      itemCount: listViewData.length,
      itemBuilder: (context, int i) {
        bool last = listViewData.length == (i + 1);
        return Padding(
          padding: const EdgeInsets.only(left: 8, bottom: 15),
          child: Row(
            mainAxisSize        : MainAxisSize.max,
            crossAxisAlignment  : CrossAxisAlignment.start,
            mainAxisAlignment   : MainAxisAlignment.start,
            children: <Widget>[
              Padding(
                padding: const EdgeInsets.only(
                  top   : 0,
                  bottom: 0,
                  left  : 0,
                  right : 12,
                ),
                child: Column(
                  children: <Widget>[
                    Icon(
                      listViewData[i].itemIcon,
                      color: Colors.white,
                      size: 20.0,
                    ),
                    if (!isCollapsed)
                      Text(
                        listViewData[i].itemText,
                        style: TextStyle(color: Colors.white, fontSize: 16)
                      ),
                  ],
                )
              ),
            ]
          ),
        );
      }
    );
  }
}