/************************************
 * flutter template using bottom nav
 ************************************/
import 'package:flutter/material.dart';
import 'package:flutter_syntax_view/flutter_syntax_view.dart';
import 'dart:convert';
import './codes.dart';

//
// labels for nav destination and body
//
List<String> labels = ['Home', 'Demo', 'Help', 'Source'];

//
// nav destinations widget for bottom nav
//
List<NavigationDestination> nav_destinations = [
  NavigationDestination(icon: Icon
    (Icons.home), label: labels[0]),
    
  NavigationDestination(icon: Icon
    (Icons.bluetooth), label: labels[1]),

  NavigationDestination(icon: Icon
    (Icons.help), label: labels[2]),    
 
  NavigationDestination(icon: Icon
    (Icons.source), label: labels[3])];

//
// class showing passing parameters
//
class Body extends StatelessWidget {
  Body(this.text);
  final String text;
  
  @override Widget build(BuildContext bc){
    return (Center(child:Text(text)));}}
  
//
// function example
//  
Widget showSource(BuildContext context){
  num line = LineSplitter().convert(code).length;
  return  SizedBox(height:16.0 * line, child:Padding(
      padding:EdgeInsets.fromLTRB(0,0,20,0), child:SyntaxView(
      code: code,
      syntax: Syntax.DART,
      syntaxTheme: SyntaxTheme.vscodeDark(),
      withZoom:true,
      withLinesCount:true,
      expanded:true)));}

//
// class statelesswidget
//
class Source extends StatelessWidget{

@override Widget build(BuildContext context) {
return Scaffold(appBar:AppBar(title: Text('Source Code')),
body: SingleChildScrollView(child:showSource(context)));}}

//
// class example, that changes icon back button
//
class Help extends StatelessWidget{
@override Widget build(BuildContext context){
  return Scaffold(appBar:AppBar(
    leading:IconButton(icon:Icon(Icons.close, color:Colors.black),
      onPressed:() => Navigator.push(context,
        MaterialPageRoute(builder:(context)=>MyApp()))),
    title: Text('Help')),
    body: Center(child:Text('Help')));}}

//
// main
//
void main() {runApp(const MyApp());}

//
// class example statefulwidget
//
class MyApp extends StatefulWidget {
  const MyApp({super.key});
  @override State<MyApp> createState() => _MyAppState();}

class _MyAppState extends State<MyApp> {
  int selectedPageIndex = 0;
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      debugShowCheckedModeBanner: false,
      title: 'Demo',
      home: Scaffold(
        body: [
          Body(labels[0]),  // change this to your own container
          Body(labels[1]),  // maybe refactor on a separate file
          Help(),           // example change back button in appbar
          Source()          // show source file example widget
        ][selectedPageIndex],
        
      bottomNavigationBar: NavigationBar(
        selectedIndex: selectedPageIndex,
          onDestinationSelected: (int index) {
            setState((){selectedPageIndex = index;});},
          destinations: nav_destinations)));}}