catatan coding: August 2020

Android Emulator pada hp kita via koneksi wifi

adb tcpip 5555

adb connect <your-phone-ip>:5555

stay connect via USB to yours computer
connect to your WIFI network (computer and mobile device both) ->same network
ping DeviceIP (must be have ping to your device)
adb kill-server
adb usb
adb tcpip 5555
1. unplug usb cable (as per @captain_majid 's comment)
adb connect yourDeviceIP
adb devices (must be see two device names , one of them is by deviceIP)
unplug USB cable

Simple BottomBar Flutter

pada contoh ini ada 4 file yg dibuat: main, homepage, settingpage, contactpage

1. main.dart

import 'package:bottombar/contactPage.dart';
import 'package:bottombar/homePage.dart';
import 'package:bottombar/settingPage.dart';
import 'package:flutter/material.dart';

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: MyBottomBar(),
    );
  }
}

class MyBottomBar extends StatefulWidget {
  @override
  _MyBottomBarState createState() => _MyBottomBarState();
}

class _MyBottomBarState extends State<MyBottomBar> {
  int _currentIndex = 0;
  final List<Widget> _children = [
    HomePage(),
    SettingPage(),
    ContactPage(),
  ];

  void onTappedBar(int index) {
    setState(() {
      _currentIndex = index;
    });
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: _children[_currentIndex],
      bottomNavigationBar: BottomNavigationBar(
        onTap: onTappedBar,
        currentIndex: _currentIndex,
        items: [
          BottomNavigationBarItem(
            icon: new Icon(Icons.home),
            title: Text('Home'),
          ),
          BottomNavigationBarItem(
            icon: new Icon(Icons.settings),
            title: Text('Setting'),
          ),
          BottomNavigationBarItem(
            icon: new Icon(Icons.contacts),
            title: Text('Contact'),
          ),
        ],
      ),
    );
  }
}

2. homePage.dart

import 'package:flutter/material.dart';

class HomePage extends StatefulWidget {
  @override
  _HomePageState createState() => _HomePageState();
}

class _HomePageState extends State<HomePage> {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Home'),
      ),
      body: Center(
        child: Text('Home Page'),
      ),
    );
  }
}

3. settingPage.dart

import 'package:flutter/material.dart';

class SettingPage extends StatefulWidget {
  @override
  _SettingPageState createState() => _SettingPageState();
}

class _SettingPageState extends State<SettingPage> {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Setting'),
      ),
      body: Center(
        child: Text('Setting Page'),
      ),
    );
  }
}

4. contactPage.dart

import 'package:flutter/material.dart';

class ContactPage extends StatefulWidget {
  @override
  _ContactPageState createState() => _ContactPageState();
}

class _ContactPageState extends State<ContactPage> {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Contact'),
      ),
      body: Center(
        child: Text('Contact Page'),
      ),
    );
  }
}

Method Setter dan getter pada OOP DART

method set and getter pada dart sedikit beda dengan yang ada pada java

pada dart menggunakan property

buat di file terpisah:

class PersegiPanjang{
    double _panjang;
    double _lebar;

// method set selain dart
    void setPanjang(double value){
        _panjang = value;
    }
// method set pada dart
    void set lebar(double value){
        _lebar = value;
    }
// method get selain dart
    double getPanjang(){
        return _panjang;
    }
// method get pada dart
    double get lebar(){
        return _lebar;
    }    
// method mengembalikan
    double get luas => _panjang * _lebar;    
}

Pada file view nya

main(List<String> arguments){
  PersegiPanjang kotak1, kotak2;

  kotak1 = new PersegiPanjang();
  kotak1.setPanjang(2);  //cara set selain dart
  kotak1.lebar = 2;  //cara set pada dart

  kotak1.getPanjang(); //get selain dart
  kotak1.lebar; //get pada dart

  kotak1.luas;  //untuk nampilin luas
}