labelBuilder property Null safety

TreemapTileWidgetBuilder? labelBuilder
final

Returns a widget for the treemap label based on the tile.

A treemap label displays additional information about the tile on a treemap.

late List<SocialMediaUsers> _socialMediaUsersData;

  @override
  void initState() {
    _socialMediaUsersData = <SocialMediaUsers>[
      SocialMediaUsers('India', 'Facebook', 280),
      SocialMediaUsers('India', 'Instagram', 88),
      SocialMediaUsers('USA', 'Facebook', 190),
      SocialMediaUsers('USA', 'Instagram', 120),
      SocialMediaUsers('Japan', 'Twitter', 48),
      SocialMediaUsers('Japan', 'Instagram', 31),
    ];
    super.initState();
  }

@override
  Widget build(BuildContext context) {
    return Scaffold(
      body: SfTreemap(
        dataCount: _socialMediaUsersData.length,
        weightValueMapper: (int index) {
          return _socialMediaUsersData[index].usersInMillions;
        },
        levels: [
          TreemapLevel(
              padding: EdgeInsets.all(2),
              groupMapper: (int index) {
                return _socialMediaUsersData[index].country;
              },
              color: Colors.red,
              labelBuilder: (BuildContext context, TreemapTile tile) {
                return Padding(
                  padding: EdgeInsets.all(4.0),
                  child: Text(tile.group),
                );
              }),
        ],
      ),
    );
  }

class SocialMediaUsers {
  const SocialMediaUsers(
    this.country,
    this.socialMedia,
    this.usersInMillions,
  );
  final String country;
  final String socialMedia;
  final double usersInMillions;
}

See also:

Implementation

final TreemapTileWidgetBuilder? labelBuilder;