128 lines
4.5 KiB
Dart
128 lines
4.5 KiB
Dart
/// Bar chart with example of a legend with customized position, justification,
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/// desired max rows, and padding. These options are shown as an example of how
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/// to use the customizations, they do not necessary have to be used together in
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/// this way. Choosing [end] as the position does not require the justification
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/// to also be [endDrawArea].
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import 'package:flutter/material.dart';
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import 'package:charts_flutter/flutter.dart' as charts;
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/// Example that shows how to build a series legend that shows measure values
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/// when a datum is selected.
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///
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/// Also shows the option to provide a custom measure formatter.
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class LegendWithMeasures extends StatelessWidget {
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LegendWithMeasures(this.seriesList, {this.animate});
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factory LegendWithMeasures.withSampleData() {
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return new LegendWithMeasures(
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_createSampleData(),
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// Disable animations for image tests.
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animate: false,
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);
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}
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final List<charts.Series> seriesList;
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final bool animate;
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@override
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Widget build(BuildContext context) {
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return new charts.BarChart(
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seriesList,
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animate: animate,
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barGroupingType: charts.BarGroupingType.grouped,
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// Add the legend behavior to the chart to turn on legends.
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// This example shows how to optionally show measure and provide a custom
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// formatter.
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behaviors: [
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new charts.SeriesLegend(
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// Positions for "start" and "end" will be left and right respectively
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// for widgets with a build context that has directionality ltr.
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// For rtl, "start" and "end" will be right and left respectively.
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// Since this example has directionality of ltr, the legend is
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// positioned on the right side of the chart.
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position: charts.BehaviorPosition.end,
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// By default, if the position of the chart is on the left or right of
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// the chart, [horizontalFirst] is set to false. This means that the
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// legend entries will grow as new rows first instead of a new column.
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horizontalFirst: false,
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// This defines the padding around each legend entry.
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cellPadding: new EdgeInsets.only(right: 4.0, bottom: 4.0),
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// Set show measures to true to display measures in series legend,
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// when the datum is selected.
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showMeasures: true,
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// Optionally provide a measure formatter to format the measure value.
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// If none is specified the value is formatted as a decimal.
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measureFormatter: (num value) {
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return value == null ? '-' : '${value}k';
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},
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),
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],
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);
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}
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/// Create series list with multiple series
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static List<charts.Series<OrdinalSales, String>> _createSampleData() {
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final desktopSalesData = [
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new OrdinalSales('2014', 5),
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new OrdinalSales('2015', 25),
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new OrdinalSales('2016', 100),
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new OrdinalSales('2017', 75),
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];
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final tabletSalesData = [
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new OrdinalSales('2014', 25),
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new OrdinalSales('2015', 50),
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// Purposely have a null data for 2016 to show the null value format.
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new OrdinalSales('2017', 20),
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];
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final mobileSalesData = [
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new OrdinalSales('2014', 10),
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new OrdinalSales('2015', 15),
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new OrdinalSales('2016', 50),
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new OrdinalSales('2017', 45),
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];
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final otherSalesData = [
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new OrdinalSales('2014', 20),
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new OrdinalSales('2015', 35),
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new OrdinalSales('2016', 15),
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new OrdinalSales('2017', 10),
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];
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return [
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new charts.Series<OrdinalSales, String>(
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id: 'Lancaster',
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domainFn: (OrdinalSales sales, _) => sales.year,
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measureFn: (OrdinalSales sales, _) => sales.sales,
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data: desktopSalesData,
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),
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new charts.Series<OrdinalSales, String>(
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id: 'Morecambe',
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domainFn: (OrdinalSales sales, _) => sales.year,
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measureFn: (OrdinalSales sales, _) => sales.sales,
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data: tabletSalesData,
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),
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new charts.Series<OrdinalSales, String>(
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id: 'Mars',
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domainFn: (OrdinalSales sales, _) => sales.year,
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measureFn: (OrdinalSales sales, _) => sales.sales,
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data: mobileSalesData,
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),
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new charts.Series<OrdinalSales, String>(
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id: 'Other',
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domainFn: (OrdinalSales sales, _) => sales.year,
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measureFn: (OrdinalSales sales, _) => sales.sales,
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data: otherSalesData,
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),
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];
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}
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}
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/// Sample ordinal data type.
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class OrdinalSales {
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OrdinalSales(this.year, this.sales);
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final String year;
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final int sales;
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}
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