FlatList for Flutter

[FlatList] widget in Flutter which will be familiar to React Native developers.

Motivation

While there are opinionated ways to build listviews in React Native, there are many ways to build listviews in Flutter. In Flutter, we can use ListView, ListView.builder(), SliverList and also when you want to make list with more than one column, you need to use GridView, SliverGrid and so on.

By providing FlatList widget in Flutter, we can move faster on implementing the ListView we want.

Installation

flutter pub add flat_list

Usage

You'll easily understand by looking at below code.

FlatList(
  onEndReached: () async {
    loading.value = true;
    await Future.delayed(const Duration(seconds: 2));
    if (context.mounted) {
      items.value += getMoreData();
      loading.value = false;
    }
  },
  onRefresh: () async {
    await Future.delayed(const Duration(seconds: 2));

    if (context.mounted) {
      items.value = data;
    }
  },
  loading: loading.value,
  listHeaderWidget: const Header(),
  listFooterWidget: const Footer(),
  listEmptyWidget: Container(
    alignment: Alignment.center,
    padding: const EdgeInsets.all(12),
    child: const Text('List is empty!'),
  ),
  data: items.value,
  buildItem: (item, index) {
    var person = items.value[index];

    return ListItemView(person: person);
  },
)

More about the differences in props compared to React Native's FlatList are listed below.

Flutter	React Native	Required
data	data	✓
buildItem	renderItem	✓
listHeaderWidget	ListHeaderComponent
listFooterWidget	ListFooterComponent
listEmptyWidget	ListEmptyComponent
onRefresh	onRefresh
onEndReached	onEndReached
``	refreshing
loading	loading
numColumns	numColumns
onEndReachedDelta	onEndReachedThreshold
controller	``
inverted	inverted

Basic setup

The complete example is available here.

FlatList requires you to provide data and buildItem:

• buildItem method is identical to renderItem in React Native.
• data is a plain list.

FlatList(
  data: items.value,
  buildItem: (item, index) {
    var person = items.value[index];

    return ListItemView(person: person);
  },
)

Adding additional views

You can provide header and footer in [FlatList]. When providing listEmptyWidget, it will be rendered when the list of data is empty.

listHeaderWidget: const Header(), // Provider any header
listFooterWidget: const Footer(), // Provider any footer
listEmptyWidget: Container(
  alignment: Alignment.center,
  padding: const EdgeInsets.all(12),
  child: const Text('List is empty!'),
),

Refresh indicator

Providing onRefresh will add [RefreshIndicator]. Therefore you can refresh the data.

onRefresh: () async {
  await Future.delayed(const Duration(seconds: 2));

  if (context.mounted) {
    items.value = data;
  }
},

Infinite scroll

Infinite scrolling is possible using onEndReached. You should also provide loading to use this feature correctly.

loading: loading.value,
onEndReached: () async {
  loading.value = true;
  await Future.delayed(const Duration(seconds: 2));
  if (context.mounted) {
    items.value += getMoreData();
    loading.value = false;
  }
},

GridView

Just by giving numColumns value greater than 1, it will render [GridView].

numColums: 3, // Value greater than 1

One column

One column	Multiple Columns

Demo

Examples are provided in /example folder.

TODO

• Support optional horizontal mode

• Separator support in ListView

• Expose scroll controller: Ability to control similar functionalities listed below.

  - [scrollToEnd](https://reactnative.dev/docs/flatlist#scrolltoend)
  - [scrollToIndex](https://reactnative.dev/docs/flatlist#scrolltoindex)
  - [scrollToItem](https://reactnative.dev/docs/flatlist#scrolltoitem)
  - [scrollToOffset](https://reactnative.dev/docs/flatlist#scrolltooffset)
  

• Support inverted

• Enhance onEndReachedDelta with similar to onEndReachedThreshold

• Test coverage

Additional information

Read our blog