Example:
/// Example of adding an initial selection behavior.
///
/// This example adds initial selection to a bar chart, but any chart can use
/// the initial selection behavior.
///
/// Initial selection is only set on the very first draw and will not be set
/// again in subsequent draws unless the behavior is reconfigured.
///
/// The selection will remain on the chart unless another behavior is added
/// that updates the selection.
import 'package:community_charts_flutter/flutter.dart' as charts;
import 'package:flutter/material.dart';
class InitialSelection extends StatelessWidget {
final List<charts.Series> seriesList;
final bool animate;
InitialSelection(this.seriesList, {this.animate});
/// Creates a [BarChart] with initial selection behavior.
factory InitialSelection.withSampleData() {
return new InitialSelection(
_createSampleData(),
// Disable animations for image tests.
animate: false,
);
}
@override
Widget build(BuildContext context) {
return new charts.BarChart(
seriesList,
animate: animate,
behaviors: [
// Initial selection can be configured by passing in:
//
// A list of datum config, specified with series ID and domain value.
// A list of series config, which is a list of series ID(s).
//
// Initial selection can be applied to any chart type.
//
// [BarChart] by default includes behaviors [SelectNearest] and
// [DomainHighlighter]. So this behavior shows the initial selection
// highlighted and when another datum is tapped, the selection changes.
new charts.InitialSelection(selectedDataConfig: [
new charts.SeriesDatumConfig<String>('Sales', '2016')
])
],
);
}
/// Create one series with sample hard coded data.
static List<charts.Series<OrdinalSales, String>> _createSampleData() {
final data = [
new OrdinalSales('2014', 5),
new OrdinalSales('2015', 25),
new OrdinalSales('2016', 100),
new OrdinalSales('2017', 75),
];
return [
new charts.Series<OrdinalSales, String>(
id: 'Sales',
colorFn: (_, __) => charts.MaterialPalette.blue.shadeDefault,
domainFn: (OrdinalSales sales, _) => sales.year,
measureFn: (OrdinalSales sales, _) => sales.sales,
data: data,
)
];
}
}
/// Sample ordinal data type.
class OrdinalSales {
final String year;
final int sales;
OrdinalSales(this.year, this.sales);
}