Flutter-Ernaehrungsapp/lib/android/pages/nav_pages/main_page.dart

import 'package:ernaehrung/android/pages/nav_pages/progress_page.dart';
import 'package:ernaehrung/android/pages/nav_pages/today_page.dart';
import 'package:flutter/material.dart';
import 'meal_plan_page.dart';

class MainPage extends StatefulWidget {
  const MainPage({Key? key}) : super(key: key);

  @override
  MainPageState createState() => MainPageState();
}

class MainPageState extends State<MainPage> {
  List pages = [
    const TodayPage(title: 'Today',),
    const MealPlanPage(title: 'Meal Plan'),
    const ProgressPage(title: 'Progress',)
  ];

  int currentIndex = 0;
  void onTap(int index){
    setState(() {
      currentIndex = index;
      getPageWithOrOutPadding();
    });
  }

  Widget getPageWithOrOutPadding(){
    if (pages[currentIndex] is TodayPage){
      return Placeholder(
        child: pages[currentIndex],
      );
    }else{
      return Padding(
        padding: const EdgeInsets.symmetric(vertical: 0, horizontal: 8),
        child: pages[currentIndex],
      );
    }
  }
  
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text('Title'),
      ),
      body: getPageWithOrOutPadding(),
      bottomNavigationBar: BottomNavigationBar(
        currentIndex: currentIndex,
        selectedItemColor: Colors.black54,
        unselectedItemColor: Colors.grey.withOpacity(0.5),
        showSelectedLabels: false,
        showUnselectedLabels: false,
        elevation: 0,
        onTap: onTap,
        items: const [
          BottomNavigationBarItem(
              icon: Icon(Icons.today),
              label: 'Today'
          ),
          BottomNavigationBarItem(
              icon: Icon(Icons.area_chart),
              label: 'Progress'
          ),
          BottomNavigationBarItem(
              icon: Icon(Icons.apple),
              label: 'Meal Plan'
          ),
        ],
      ),
    );
  }
}