Best way to implement the tree map chart in flutter?

Question

How can I add Tree Map chart in flutter, previously 'tree_map' library were supported. But its updated two years ago.

Answer 1

You can use an alternative library like syncfusion_flutter_treemap

Implementation straightforward importing the package, initialize the treemap widget as a child of any widget.

@override
Widget build(BuildContext context) {
  return Scaffold(
    body: Center(
      child: SfTreemap(),
    ),
  );
}

Then we need to map the data source

late List<SocialMediaUsers> _source;

@override
void initState() {
  _source = <SocialMediaUsers>[
    SocialMediaUsers('India', 'Facebook', 25.4),
    SocialMediaUsers('USA', 'Instagram', 19.11),
    SocialMediaUsers('Japan', 'Facebook', 13.3),
    SocialMediaUsers('Germany', 'Instagram', 10.65),
    SocialMediaUsers('France', 'Twitter', 7.54),
    SocialMediaUsers('UK', 'Instagram', 4.93),
  ];
  super.initState();
}

@override
Widget build(BuildContext context) {
  return Scaffold(
    body: SfTreemap(
      dataCount: _source.length,
      weightValueMapper: (int index) {
        return _source[index].usersInMillions;
      },
      levels: [
        TreemapLevel(
          groupMapper: (int index) {
            return _source[index].country;
          },
        ),
      ],
    ),
  );
}

class SocialMediaUsers {
  const SocialMediaUsers(this.country, this.socialMedia, this.usersInMillions);

  final String country;
  final String socialMedia;
  final double usersInMillions;
}

Disclaimer:: above examples taken from the official package link