Elvis10ten

itemBuilder: (context, index) {
  final Map currency = _currencies[index];
  final MaterialColor color = _colors[index % _colors.length];
}

Elvis10ten

Widget _getListViewWidget() {
    // We want the ListView to have the flexibility to expand to fill the
    // available space in the vertical axis
    return new Flexible(
        child: new ListView.builder(
            // The number of items to show
            itemCount: _currencies.length,
            // Callback that should return ListView children
            // The index parameter = 0...(itemCount-1)
            itemBuilder: (context, index) {

Elvis10ten

Widget _getAppTitleWidget() {
    return new Text(
      'Cryptocurrencies',
      style: new TextStyle(
          color: Colors.white,
          fontWeight: FontWeight.bold,
          fontSize: 24.0),
    );
  }

Elvis10ten

Widget _buildBody() {
    return new Container(
      // A top margin of 56.0. A left and right margin of 8.0. And a bottom margin of 0.0.
      margin: const EdgeInsets.fromLTRB(8.0, 56.0, 8.0, 0.0),
      child: new Column(
        // A column widget can have several widgets that are placed in a top down fashion
        children: <Widget>[
          _getAppTitleWidget(),
          _getListViewWidget()
        ],

Elvis10ten

@override
  Widget build(BuildContext context) {
    return new Scaffold(
      body: _buildBody(),
      backgroundColor: Colors.blue,
    );
  }

Elvis10ten

class CryptoListWidget extends StatelessWidget {
  
  // This is a list of material colors. Feel free to add more colors, it won't break the code
  final List<MaterialColor> _colors = [Colors.blue, Colors.indigo, Colors.red];
  // The underscore before a variable name marks it as a private variable
  final List _currencies;

  // This is a constructor in Dart. We are assigning the value passed to the constructor
  // to the _currencies variable
  CryptoListWidget(this._currencies);

Elvis10ten

void main() async {
  // Bad practice alert :). You should ideally show the UI, and probably a progress view,
  // then when the requests completes, update the UI to show the data.
  List currencies = await getCurrencies();
  print(currencies);
  
  runApp(new MaterialApp(
    home: new CryptoListWidget(currencies),
  ));
}

Elvis10ten

import 'package:flutter/material.dart';

Elvis10ten

import 'dart:async';
import 'dart:convert';
import 'package:http/http.dart' as http;

Elvis10ten

// Since we are using await within the main function, we have to make it asynchronous too
void main() async {
  // Testing the getCurrencies function
  // We wait for the currency data to arrive
  List currencies = await getCurrencies();
  // Before printing it to the Console
  print(currencies);
  
  runApp(new MaterialApp(
    home: new Center(