trying to use a listview with cards. for some reason i am not being allowed to enter my created variables

card.dart

import 'package:flutter/material.dart';

class ListCard extends StatelessWidget {

  final String backgroundImagePath;
  final String title;
  final String subtitle;
  final int numberOfTrophies;
  final IconData icon;
  final Image iconAsset;

  ListCard([
    this.subtitle,
    this.title,
    this.backgroundImagePath,
    this.icon,
    this.iconAsset,
    this.numberOfTrophies
  ]);


  @override
  Widget build(BuildContext context) {
    return new Padding(
      padding: const EdgeInsets.only(
          left: 10.0,
          right: 10.0,
          bottom: 10.0
      ),
      child: new Card(
        elevation: 10.0,
        child: new Column(
          children: <Widget>[
            new Image.asset(
              backgroundImagePath,
              width: double.infinity,
              height: 150.0,
              fit: BoxFit.cover,
            ),
            new Container(
              color: Colors.white,
              child: new Row(
                children: <Widget>[
                  new Padding(
                    padding: const EdgeInsets.all(15.0),
                    child: new Container(
                      padding: const EdgeInsets.all(10.0),
                      decoration: new BoxDecoration(
                          color: Colors.green,
                          borderRadius: new BorderRadius.all(
                              const Radius.circular(15.0)
                          )
                      ),
                      child: new Image(
                          image: new AssetImage(backgroundImagePath)
                      )
                    ),
                  ),
                  new Expanded(
                    child: new Column(
                      crossAxisAlignment: CrossAxisAlignment.start,
                      children: <Widget>[
                        new Text(title,
                          style: new TextStyle(fontSize: 25.0),
                        ),
                        new Text(subtitle,
                          style: new TextStyle(fontSize: 17.0),
                        )
                      ],
                    ),
                  ),
                  new Container(
                    width: 2.0,
                    height: 70.0,
                    decoration: new BoxDecoration(
                        gradient: new LinearGradient(
                            colors: [
                              Colors.green,
                              Colors.white
                            ],
                            begin: Alignment.topRight,
                            end: Alignment.bottomRight
                        )
                    ),
                  ),
                  new Padding(
                    padding: const EdgeInsets.only(
                        left: 15.0,
                        right: 15.0
                    ),
                    child: new Column(
                      children: <Widget>[
                        new Image.asset(
                          'assets/trophy_icon.png',
                          height: 30.0
                        ),
                        new Text('$numberOfTrophies')
                      ],
                    ),
                  )
                ],
              ),
            ),
          ],
        ),
      ),
    );
  }
}

main.dart

import 'package:flutter/material.dart';
import 'ui_elements/card.dart';

void main() => runApp(new MyApp());

class MyApp extends StatelessWidget {

  @override
  Widget build(BuildContext context) {
    return new MaterialApp(
      title: '1 Way',
      theme: new ThemeData(
        primarySwatch: Colors.green,
      ),
      home: new MyHomePage(),
    );
  }
}

class MyHomePage extends StatefulWidget{
  @override
  State createState() => new MyHomePageState();
}

class MyHomePageState extends State<MyHomePage>
    with SingleTickerProviderStateMixin{

  TabController tabController;

  @override
  void initState() {
    super.initState();
    tabController = new TabController(length: 4, vsync: this);
  }

  @override
  Widget build(BuildContext context) {
    return new Container(
      child: new Scaffold(
        backgroundColor: Colors.transparent,
        appBar: new AppBar(
          title: new Image.asset('assets/logo_white_text.png'),
          centerTitle: true,
          leading: new IconButton(
              icon: new Icon(Icons.menu, color: Colors.white),
              onPressed: (){
                //TODO:
              }
          ),
          bottom: new TabBar(
              controller: tabController,
              tabs: <Widget>[
                new Tab(
                  child: new Image.asset('assets/freerun_page_title.png'),
                ),
                new Tab(
                  child: new Image.asset('assets/compete_page_title.png'),
                ),
                new Tab(
                  child: new Image.asset('assets/raffle_page_title.png'),
                ),
                new Tab(
                  child: new Image.asset('assets/shop_page_title.png'),
                )
              ],
          ),
        ),
        body: new ListView(
          children: <Widget>[
            new ListCard(title), <<<<<<<<<< in android studio i get no option for auto complete
          ],
        ),
      ),
    );
  }
}