lazy_load_scrollview 1.3.0

A wrapper for a ScrollView that will trigger a callback when the bottom of the page is reached

example/lib/main.dart

import 'package:flutter/material.dart';
import 'package:lazy_load_scrollview/lazy_load_scrollview.dart';

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

class MyApp extends StatelessWidget {
  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return new MaterialApp(
      title: 'Lazy Load Demo',
      home: new MyHomePage(title: 'Lazy Load Demo'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  MyHomePage({Key? key, required this.title}) : super(key: key);

  final String title;

  @override
  _MyHomePageState createState() => new _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  List<int> verticalData = [];
  List<int> horizontalData = [];

  final int increment = 10;

  bool isLoadingVertical = false;
  bool isLoadingHorizontal = false;

  @override
  void initState() {
    _loadMoreVertical();
    _loadMoreHorizontal();
    super.initState();
  }

  Future _loadMoreVertical() async {
    setState(() {
      isLoadingVertical = true;
    });

    // Add in an artificial delay
    await new Future.delayed(const Duration(seconds: 2));

    verticalData.addAll(
        List.generate(increment, (index) => verticalData.length + index));

    setState(() {
      isLoadingVertical = false;
    });
  }

  Future _loadMoreHorizontal() async {
    setState(() {
      isLoadingHorizontal = true;
    });

    // Add in an artificial delay
    await new Future.delayed(const Duration(seconds: 2));

    horizontalData.addAll(
        List.generate(increment, (index) => horizontalData.length + index));

    setState(() {
      isLoadingHorizontal = false;
    });
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(widget.title),
      ),
      body: LazyLoadScrollView(
        isLoading: isLoadingVertical,
        onEndOfPage: () => _loadMoreVertical(),
        child: Scrollbar(
          child: ListView(
            children: [
              Padding(
                padding: const EdgeInsets.all(8.0),
                child: Text(
                  'Nested horizontal ListView',
                  textAlign: TextAlign.center,
                ),
              ),
              Container(
                  height: 180,
                  child: LazyLoadScrollView(
                      isLoading: isLoadingHorizontal,
                      scrollDirection: Axis.horizontal,
                      onEndOfPage: () => _loadMoreHorizontal(),
                      child: Scrollbar(
                          child: ListView.builder(
                              itemCount: horizontalData.length,
                              scrollDirection: Axis.horizontal,
                              itemBuilder: (context, position) {
                                return DemoItem(position);
                              })))),
              Padding(
                padding: const EdgeInsets.all(8.0),
                child: Text(
                  'Vertical ListView',
                  textAlign: TextAlign.center,
                ),
              ),
              ListView.builder(
                shrinkWrap: true,
                physics: NeverScrollableScrollPhysics(),
                itemCount: verticalData.length,
                itemBuilder: (context, position) {
                  return DemoItem(position);
                },
              ),
            ],
          ),
        ),
      ),
    );
  }
}

class DemoItem extends StatelessWidget {
  final int position;

  const DemoItem(
    this.position, {
    Key? key,
  }) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return SizedBox(
      width: MediaQuery.of(context).size.width,
      child: Card(
        child: Padding(
          padding: const EdgeInsets.all(8.0),
          child: Column(
            crossAxisAlignment: CrossAxisAlignment.start,
            children: <Widget>[
              Row(
                crossAxisAlignment: CrossAxisAlignment.center,
                children: <Widget>[
                  Container(
                    color: Colors.grey,
                    height: 40.0,
                    width: 40.0,
                  ),
                  SizedBox(width: 8.0),
                  Text("Item $position"),
                ],
              ),
              Text(
                  "Lorem ipsum dolor sit amet, consectetur adipiscing elit. Quisque sed vulputate orci. Proin id scelerisque velit. Fusce at ligula ligula. Donec fringilla sapien odio, et faucibus tortor finibus sed. Aenean rutrum ipsum in sagittis auctor. Pellentesque mattis luctus consequat. Sed eget sapien ut nibh rhoncus cursus. Donec eget nisl aliquam, ornare sapien sit amet, lacinia quam."),
            ],
          ),
        ),
      ),
    );
  }
}