Example:
/// Line chart with line annotations example.
import 'package:community_charts_flutter/flutter.dart' as charts;
import 'package:flutter/material.dart';
class LineLineAnnotationChart extends StatelessWidget {
final List<charts.Series> seriesList;
final bool animate;
LineLineAnnotationChart(this.seriesList, {this.animate});
/// Creates a [LineChart] with sample data and line annotations.
///
/// The second annotation extends beyond the range of the series data,
/// demonstrating the effect of the [Charts.RangeAnnotation.extendAxis] flag.
/// This can be set to false to disable range extension.
factory LineLineAnnotationChart.withSampleData() {
return new LineLineAnnotationChart(
_createSampleData(),
// Disable animations for image tests.
animate: false,
);
}
@override
Widget build(BuildContext context) {
return new charts.LineChart(seriesList, animate: animate, behaviors: [
new charts.RangeAnnotation([
new charts.LineAnnotationSegment(
1.0, charts.RangeAnnotationAxisType.domain,
startLabel: 'Domain 1'),
new charts.LineAnnotationSegment(
4, charts.RangeAnnotationAxisType.domain,
endLabel: 'Domain 2', color: charts.MaterialPalette.gray.shade200),
new charts.LineAnnotationSegment(
20, charts.RangeAnnotationAxisType.measure,
startLabel: 'Measure 1 Start',
endLabel: 'Measure 1 End',
color: charts.MaterialPalette.gray.shade300),
new charts.LineAnnotationSegment(
65, charts.RangeAnnotationAxisType.measure,
startLabel: 'Measure 2 Start',
endLabel: 'Measure 2 End',
color: charts.MaterialPalette.gray.shade400),
]),
]);
}
/// Create one series with sample hard coded data.
static List<charts.Series<LinearSales, int>> _createSampleData() {
final data = [
new LinearSales(0, 5),
new LinearSales(1, 25),
new LinearSales(2, 100),
new LinearSales(3, 75),
];
return [
new charts.Series<LinearSales, int>(
id: 'Sales',
domainFn: (LinearSales sales, _) => sales.year,
measureFn: (LinearSales sales, _) => sales.sales,
data: data,
)
];
}
}
/// Sample linear data type.
class LinearSales {
final int year;
final int sales;
LinearSales(this.year, this.sales);
}