SplittingApp intoWidgets

 import "package:flutter/material.dart";

void main() {
  runApp(demoApp());
}
class demoApp extends StatelessWidget {
  demoApp({super.key});

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      debugShowCheckedModeBanner: false,
      title: "Splitting app into Widgets",
      theme: ThemeData(
        primarySwatch: Colors.indigo,
      ),
      home: SplittingWidgets(), //First Launcher Screen
    );
  }
}
class SplittingWidgets extends StatelessWidget {
  SplittingWidgets({super.key});

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text("Splitting Widgets"),
      ),
      body: Container(
        child: Column(
          children: [
            CatItems(),

            Contact(),

            SubCatItems(),

            BottomMenu(),
          ],
        ),
      ),
    );
  }
}

class CatItems extends StatelessWidget {
  CatItems({super.key});

  @override
  Widget build(BuildContext context) {
    return  Expanded(
      flex: 2,
      child: Container(
        color: Colors.blue,
        child: ListView.builder(
          itemBuilder: (context, index) {
            return Padding(
              padding: const EdgeInsets.all(13.0),
              child: SizedBox(
                width: 90,
                child: CircleAvatar(
                  backgroundColor: Colors.yellowAccent,
                ),
              ),
            );
          },
          itemCount: 30,
          scrollDirection: Axis.horizontal,
        ),
      ),
    );
  }
}
class Contact extends StatelessWidget {
  Contact({super.key});

  @override
  Widget build(BuildContext context) {
    return Expanded(
      flex: 4,
      child: Container(
        color: Colors.orange,
        child: ListView.builder(
          itemBuilder: (context, index) {
            return Padding(
              padding: const EdgeInsets.all(8.0),
              child: ListTile(
                leading: CircleAvatar(
                  backgroundColor: Colors.deepPurple,
                ),
                title: Text("Name"),
                subtitle: Text("Mobile No"),
                trailing: Icon(Icons.delete,),
              ),
            );
          },
        ),
      ),
    );
  }
}
class SubCatItems extends StatelessWidget {
  SubCatItems({super.key});

  @override
  Widget build(BuildContext context) {
    return Expanded(
      flex: 2,
      child: Container(
        color: Colors.blueGrey,
        child: ListView.builder(
          itemBuilder: (context, index) {
            return Padding(
              padding: const EdgeInsets.all(8.0),
              child: Container(
                width: 150,
                decoration: BoxDecoration(
                  borderRadius: BorderRadius.circular(11.0,),
                  color: Colors.lightBlueAccent,
                ),
              ),
            );
          },
          itemCount: 10,
          scrollDirection: Axis.horizontal,
        ),
      ),
    );
  }
}
class BottomMenu extends StatelessWidget {
  BottomMenu({super.key});

  @override
  Widget build(BuildContext context) {
    return Expanded(
      flex: 2,
      child: Container(
        color: Colors.green,
        child: Padding(
          padding: const EdgeInsets.all(8.0),
          child: GridView.count(
            crossAxisCount: 2,
            children: [
              Container(color: Colors.limeAccent, width: 20, height: 20,),
              Container(color: Colors.limeAccent,),
              Container(color: Colors.limeAccent,),
              Container(color: Colors.limeAccent,),
              Container(color: Colors.limeAccent,),
              Container(color: Colors.limeAccent,),
              Container(color: Colors.limeAccent,),
              Container(color: Colors.limeAccent,),
              Container(color: Colors.limeAccent,),
              Container(color: Colors.limeAccent,),
              Container(color: Colors.limeAccent,),
              Container(color: Colors.limeAccent,),
              Container(color: Colors.limeAccent,),
              Container(color: Colors.limeAccent,),
              Container(color: Colors.limeAccent,),
            ],
            crossAxisSpacing: 20,
            mainAxisSpacing: 20,
            scrollDirection: Axis.horizontal,

          ),
        ),
      ),
    );
  }
}