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samples/web/charts/lib/legends/series_legend_with_measures...

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// Copyright 2018 the Charts project authors. Please see the AUTHORS file
// for details.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
/// Bar chart with example of a legend with customized position, justification,
/// desired max rows, and padding. These options are shown as an example of how
/// to use the customizations, they do not necessary have to be used together in
/// this way. Choosing [end] as the position does not require the justification
/// to also be [endDrawArea].
// EXCLUDE_FROM_GALLERY_DOCS_START
import 'dart:math';
// EXCLUDE_FROM_GALLERY_DOCS_END
import 'package:flutter/material.dart';
import 'package:charts_flutter/flutter.dart' as charts;
/// Example that shows how to build a series legend that shows measure values
/// when a datum is selected.
///
/// Also shows the option to provide a custom measure formatter.
class LegendWithMeasures extends StatelessWidget {
final List<charts.Series> seriesList;
final bool animate;
const LegendWithMeasures(this.seriesList, {this.animate, Key key})
: super(key: key);
factory LegendWithMeasures.withSampleData() {
return LegendWithMeasures(
_createSampleData(),
// Disable animations for image tests.
animate: false,
);
}
// EXCLUDE_FROM_GALLERY_DOCS_START
// This section is excluded from being copied to the gallery.
// It is used for creating random series data to demonstrate animation in
// the example app only.
factory LegendWithMeasures.withRandomData() {
return LegendWithMeasures(_createRandomData());
}
/// Create random data.
static List<charts.Series<OrdinalSales, String>> _createRandomData() {
final random = Random();
final desktopSalesData = [
OrdinalSales('2014', 5),
OrdinalSales('2015', 25),
OrdinalSales('2016', 100),
OrdinalSales('2017', 75),
];
final tabletSalesData = [
OrdinalSales('2014', random.nextInt(100)),
OrdinalSales('2015', random.nextInt(100)),
OrdinalSales('2016', random.nextInt(100)),
OrdinalSales('2017', random.nextInt(100)),
];
final mobileSalesData = [
OrdinalSales('2014', random.nextInt(100)),
OrdinalSales('2015', random.nextInt(100)),
OrdinalSales('2016', random.nextInt(100)),
OrdinalSales('2017', random.nextInt(100)),
];
final otherSalesData = [
OrdinalSales('2014', random.nextInt(100)),
OrdinalSales('2015', random.nextInt(100)),
OrdinalSales('2016', random.nextInt(100)),
OrdinalSales('2017', random.nextInt(100)),
];
return [
charts.Series<OrdinalSales, String>(
id: 'Desktop',
domainFn: (OrdinalSales sales, _) => sales.year,
measureFn: (OrdinalSales sales, _) => sales.sales,
data: desktopSalesData,
),
charts.Series<OrdinalSales, String>(
id: 'Tablet',
domainFn: (OrdinalSales sales, _) => sales.year,
measureFn: (OrdinalSales sales, _) => sales.sales,
data: tabletSalesData,
),
charts.Series<OrdinalSales, String>(
id: 'Mobile',
domainFn: (OrdinalSales sales, _) => sales.year,
measureFn: (OrdinalSales sales, _) => sales.sales,
data: mobileSalesData,
),
charts.Series<OrdinalSales, String>(
id: 'Other',
domainFn: (OrdinalSales sales, _) => sales.year,
measureFn: (OrdinalSales sales, _) => sales.sales,
data: otherSalesData,
),
];
}
// EXCLUDE_FROM_GALLERY_DOCS_END
@override
Widget build(BuildContext context) {
return charts.BarChart(
seriesList,
animate: animate,
barGroupingType: charts.BarGroupingType.grouped,
// Add the legend behavior to the chart to turn on legends.
// This example shows how to optionally show measure and provide a custom
// formatter.
behaviors: [
// EXCLUDE_FROM_GALLERY_DOCS_START
// This section is excluded from being copied to the gallery.
// This is added in order to generate the image for the gallery to show
// an initial selection so that measure values are shown in the gallery.
charts.InitialSelection(
selectedDataConfig: [
charts.SeriesDatumConfig('Desktop', '2016'),
charts.SeriesDatumConfig('Tablet', '2016'),
charts.SeriesDatumConfig('Mobile', '2016'),
charts.SeriesDatumConfig('Other', '2016'),
],
),
// EXCLUDE_FROM_GALLERY_DOCS_END
charts.SeriesLegend(
// Positions for "start" and "end" will be left and right respectively
// for widgets with a build context that has directionality ltr.
// For rtl, "start" and "end" will be right and left respectively.
// Since this example has directionality of ltr, the legend is
// positioned on the right side of the chart.
position: charts.BehaviorPosition.end,
// By default, if the position of the chart is on the left or right of
// the chart, [horizontalFirst] is set to false. This means that the
// legend entries will grow as new rows first instead of a new column.
horizontalFirst: false,
// This defines the padding around each legend entry.
cellPadding: const EdgeInsets.only(right: 4.0, bottom: 4.0),
// Set show measures to true to display measures in series legend,
// when the datum is selected.
showMeasures: true,
// Optionally provide a measure formatter to format the measure value.
// If none is specified the value is formatted as a decimal.
measureFormatter: (num value) {
return value == null ? '-' : '${value}k';
},
),
],
);
}
/// Create series list with multiple series
static List<charts.Series<OrdinalSales, String>> _createSampleData() {
final desktopSalesData = [
OrdinalSales('2014', 5),
OrdinalSales('2015', 25),
OrdinalSales('2016', 100),
OrdinalSales('2017', 75),
];
final tabletSalesData = [
OrdinalSales('2014', 25),
OrdinalSales('2015', 50),
// Purposely have a missing datum for 2016 to show the null measure format
OrdinalSales('2017', 20),
];
final mobileSalesData = [
OrdinalSales('2014', 10),
OrdinalSales('2015', 15),
OrdinalSales('2016', 50),
OrdinalSales('2017', 45),
];
final otherSalesData = [
OrdinalSales('2014', 20),
OrdinalSales('2015', 35),
OrdinalSales('2016', 15),
OrdinalSales('2017', 10),
];
return [
charts.Series<OrdinalSales, String>(
id: 'Desktop',
domainFn: (OrdinalSales sales, _) => sales.year,
measureFn: (OrdinalSales sales, _) => sales.sales,
data: desktopSalesData,
),
charts.Series<OrdinalSales, String>(
id: 'Tablet',
domainFn: (OrdinalSales sales, _) => sales.year,
measureFn: (OrdinalSales sales, _) => sales.sales,
data: tabletSalesData,
),
charts.Series<OrdinalSales, String>(
id: 'Mobile',
domainFn: (OrdinalSales sales, _) => sales.year,
measureFn: (OrdinalSales sales, _) => sales.sales,
data: mobileSalesData,
),
charts.Series<OrdinalSales, String>(
id: 'Other',
domainFn: (OrdinalSales sales, _) => sales.year,
measureFn: (OrdinalSales sales, _) => sales.sales,
data: otherSalesData,
),
];
}
}
/// Sample ordinal data type.
class OrdinalSales {
final String year;
final int sales;
OrdinalSales(this.year, this.sales);
}