Bitcoin Ticker

Bitcoin Ticker 

 

API site : 

https://apiv2.bitcoinaverage.com/#ticker-data-per-symbol

 

 - Final code

1. pubspec.yaml

name: bitcoin_ticker

description: A new Flutter application.

version: 1.0.0+1

environment:

  sdk: ">=2.1.0 <3.0.0"

 

dependencies:

  flutter:

    sdk: flutter

 

  cupertino_icons: ^0.1.2

  http: ^0.12.0+2

 

dev_dependencies:

  flutter_test:

    sdk: flutter

flutter:

  uses-material-design: true

 

1. main.dart

import 'package:flutter/material.dart';

import 'price_screen.dart';

 

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

 

class MyApp extends StatelessWidget {

  @override

  Widget build(BuildContext context) {

    return MaterialApp(

      theme: ThemeData.dark().copyWith(

          primaryColor: Colors.lightBlue,

          scaffoldBackgroundColor: Colors.white),

      home: PriceScreen(),

    );

  }

}

 

1. price_screen.dart

import 'package:flutter/material.dart';

import 'package:flutter/cupertino.dart';

import 'coin_data.dart';

import 'dart:io' show Platform;

 

class PriceScreen extends StatefulWidget {

  @override

  _PriceScreenState createState() => _PriceScreenState();

}

 

class _PriceScreenState extends State<PriceScreen> {

  String selectedCurrency = 'AUD';

 

  DropdownButton<String> androidDropdown() {

    List<DropdownMenuItem<String>> dropdownItems = [];

    for (String currency in currenciesList) {

      var newItem = DropdownMenuItem(

        child: Text(currency),

        value: currency,

      );

      dropdownItems.add(newItem);

    }

 

    return DropdownButton<String>(

      value: selectedCurrency,

      items: dropdownItems,

      onChanged: (value) {

        setState(() {

          selectedCurrency = value;

          getData();

        });

      },

    );

  }

 

  CupertinoPicker iOSPicker() {

    List<Text> pickerItems = [];

    for (String currency in currenciesList) {

      pickerItems.add(Text(currency));

    }

 

    return CupertinoPicker(

      backgroundColor: Colors.lightBlue,

      itemExtent: 32.0,

      onSelectedItemChanged: (selectedIndex) {

        setState(() {

          selectedCurrency = currenciesList[selectedIndex];

          getData();

        });

      },

      children: pickerItems,

    );

  }

 

  Map<String, String> coinValues = {};

  bool isWaiting = false;

 

  void getData() async {

    isWaiting = true;

    try {

      var data = await CoinData().getCoinData(selectedCurrency);

      isWaiting = false;

      setState(() {

        coinValues = data;

      });

    } catch (e) {

      print(e);

    }

  }

 

  @override

  void initState() {

    super.initState();

    getData();

  }

 

  Column makeCards() {

    List<CryptoCard> cryptoCards = [];

    for (String crypto in cryptoList) {

      cryptoCards.add(

        CryptoCard(

          cryptoCurrency: crypto,

          selectedCurrency: selectedCurrency,

          value: isWaiting ? '?' : coinValues[crypto],

        ),

      );

    }

    return Column(

      crossAxisAlignment: CrossAxisAlignment.stretch,

      children: cryptoCards,

    );

  }

 

  @override

  Widget build(BuildContext context) {

    return Scaffold(

      appBar: AppBar(

        title: Text('🤑 Coin Ticker'),

      ),

      body: Column(

        mainAxisAlignment: MainAxisAlignment.spaceBetween,

        crossAxisAlignment: CrossAxisAlignment.stretch,

        children: <Widget>[

          makeCards(),

          Container(

            height: 150.0,

            alignment: Alignment.center,

            padding: EdgeInsets.only(bottom: 30.0),

            color: Colors.lightBlue,

            child: Platform.isIOS ? iOSPicker() : androidDropdown(),

          ),

        ],

      ),

    );

  }

}

 

class CryptoCard extends StatelessWidget {

  const CryptoCard({

    this.value,

    this.selectedCurrency,

    this.cryptoCurrency,

  });

 

  final String value;

  final String selectedCurrency;

  final String cryptoCurrency;

 

  @override

  Widget build(BuildContext context) {

    return Padding(

      padding: EdgeInsets.fromLTRB(18.0, 18.0, 18.0, 0),

      child: Card(

        color: Colors.lightBlueAccent,

        elevation: 5.0,

        shape: RoundedRectangleBorder(

          borderRadius: BorderRadius.circular(10.0),

        ),

        child: Padding(

          padding: EdgeInsets.symmetric(vertical: 15.0, horizontal: 28.0),

          child: Text(

            '1 $cryptoCurrency = $value $selectedCurrency',

            textAlign: TextAlign.center,

            style: TextStyle(

              fontSize: 20.0,

              color: Colors.white,

            ),

          ),

        ),

      ),

    );

  }

}

 

1. coin.dart

import 'dart:convert';

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

 

const List<String> currenciesList = [

  'AUD',

  'BRL',

  'CAD',

  'CNY',

  'EUR',

  'GBP',

  'HKD',

  'IDR',

  'ILS',

  'INR',

  'JPY',

  'MXN',

  'NOK',

  'NZD',

  'PLN',

  'RON',

  'RUB',

  'SEK',

  'SGD',

  'USD',

  'ZAR'

];

 

const List<String> cryptoList = ['BTC', 'ETH', 'LTC'];

 

const bitcoinAverageURL =

    'https://apiv2.bitcoinaverage.com/indices/global/ticker';

 

class CoinData {

  Future getCoinData(String selectedCurrency) async {

    Map<String, String> cryptoPrices = {};

    for (String crypto in cryptoList) {

      String requestURL = '$bitcoinAverageURL/$crypto$selectedCurrency';

      http.Response response = await http.get(requestURL);

      if (response.statusCode == 200) {

        var decodedData = jsonDecode(response.body);

        double lastPrice = decodedData['last'];

        cryptoPrices[crypto] = lastPrice.toStringAsFixed(0);

      } else {

        print(response.statusCode);

        throw 'Problem with the get request';

      }

    }

    return cryptoPrices;

  }

}