web/chart: fix sample (#909)

2025-11-08 22:09:06 +00:00 · 2021-10-07 08:10:34 +11:00
parent 0fe216a1cf
commit 2d9ba2f9eb
118 changed files with 3655 additions and 3511 deletions
--- a/web/charts/lib/scatter_plot_chart/animation_zoom.dart
+++ b/web/charts/lib/scatter_plot_chart/animation_zoom.dart
@@ -25,11 +25,12 @@ class ScatterPlotAnimationZoomChart extends StatelessWidget {
  final List<charts.Series> seriesList;
  final bool animate;

-  ScatterPlotAnimationZoomChart(this.seriesList, {this.animate});
+  const ScatterPlotAnimationZoomChart(this.seriesList, {this.animate, Key key})
+      : super(key: key);

  /// Creates a [ScatterPlotChart] with sample data and no transition.
  factory ScatterPlotAnimationZoomChart.withSampleData() {
-    return new ScatterPlotAnimationZoomChart(
+    return ScatterPlotAnimationZoomChart(
      _createSampleData(),
      // Disable animations for image tests.
      animate: false,
@@ -41,25 +42,25 @@ class ScatterPlotAnimationZoomChart extends StatelessWidget {
  // It is used for creating random series data to demonstrate animation in
  // the example app only.
  factory ScatterPlotAnimationZoomChart.withRandomData() {
-    return new ScatterPlotAnimationZoomChart(_createRandomData());
+    return ScatterPlotAnimationZoomChart(_createRandomData());
  }

  /// Create random data.
  static List<charts.Series<LinearSales, num>> _createRandomData() {
-    final random = new Random();
+    final random = Random();

    final data = <LinearSales>[];

-    final makeRadius = (int value) => (random.nextInt(value) + 2).toDouble();
+    makeRadius(int value) => (random.nextInt(value) + 2).toDouble();

    for (var i = 0; i < 100; i++) {
-      data.add(new LinearSales(i, random.nextInt(100), makeRadius(4)));
+      data.add(LinearSales(i, random.nextInt(100), makeRadius(4)));
    }

-    final maxMeasure = 100;
+    const maxMeasure = 100;

    return [
-      new charts.Series<LinearSales, int>(
+      charts.Series<LinearSales, int>(
        id: 'Sales',
        colorFn: (LinearSales sales, _) {
          // Color bucket the measure column value into 3 distinct colors.
@@ -84,34 +85,32 @@ class ScatterPlotAnimationZoomChart extends StatelessWidget {

  @override
  Widget build(BuildContext context) {
-    return new charts.ScatterPlotChart(seriesList,
-        animate: animate,
-        behaviors: [
-          new charts.PanAndZoomBehavior(),
-        ]);
+    return charts.ScatterPlotChart(seriesList, animate: animate, behaviors: [
+      charts.PanAndZoomBehavior(),
+    ]);
  }

  /// Create one series with sample hard coded data.
  static List<charts.Series<LinearSales, int>> _createSampleData() {
    final data = [
-      new LinearSales(0, 5, 3.0),
-      new LinearSales(10, 25, 5.0),
-      new LinearSales(12, 75, 4.0),
-      new LinearSales(13, 225, 5.0),
-      new LinearSales(16, 50, 4.0),
-      new LinearSales(24, 75, 3.0),
-      new LinearSales(25, 100, 3.0),
-      new LinearSales(34, 150, 5.0),
-      new LinearSales(37, 10, 4.5),
-      new LinearSales(45, 300, 8.0),
-      new LinearSales(52, 15, 4.0),
-      new LinearSales(56, 200, 7.0),
+      LinearSales(0, 5, 3.0),
+      LinearSales(10, 25, 5.0),
+      LinearSales(12, 75, 4.0),
+      LinearSales(13, 225, 5.0),
+      LinearSales(16, 50, 4.0),
+      LinearSales(24, 75, 3.0),
+      LinearSales(25, 100, 3.0),
+      LinearSales(34, 150, 5.0),
+      LinearSales(37, 10, 4.5),
+      LinearSales(45, 300, 8.0),
+      LinearSales(52, 15, 4.0),
+      LinearSales(56, 200, 7.0),
    ];

-    final maxMeasure = 300;
+    const maxMeasure = 300;

    return [
-      new charts.Series<LinearSales, int>(
+      charts.Series<LinearSales, int>(
        id: 'Sales',
        colorFn: (LinearSales sales, _) {
          // Color bucket the measure column value into 3 distinct colors.
--- a/web/charts/lib/scatter_plot_chart/bucketing_axis.dart
+++ b/web/charts/lib/scatter_plot_chart/bucketing_axis.dart
@@ -29,11 +29,12 @@ class BucketingAxisScatterPlotChart extends StatelessWidget {
  final List<charts.Series> seriesList;
  final bool animate;

-  BucketingAxisScatterPlotChart(this.seriesList, {this.animate});
+  const BucketingAxisScatterPlotChart(this.seriesList, {this.animate, Key key})
+      : super(key: key);

  /// Creates a [ScatterPlotChart] with sample data and no transition.
  factory BucketingAxisScatterPlotChart.withSampleData() {
-    return new BucketingAxisScatterPlotChart(
+    return BucketingAxisScatterPlotChart(
      _createSampleData(),
      // Disable animations for image tests.
      animate: false,
@@ -45,61 +46,55 @@ class BucketingAxisScatterPlotChart extends StatelessWidget {
  // It is used for creating random series data to demonstrate animation in
  // the example app only.
  factory BucketingAxisScatterPlotChart.withRandomData() {
-    return new BucketingAxisScatterPlotChart(_createRandomData());
+    return BucketingAxisScatterPlotChart(_createRandomData());
  }

  /// Create random data.
  static List<charts.Series<LinearSales, num>> _createRandomData() {
-    final random = new Random();
+    final random = Random();

-    final makeRadius = (int value) => (random.nextInt(value) + 6).toDouble();
+    makeRadius(int value) => (random.nextInt(value) + 6).toDouble();

    // Make sure that the measure values for the first five series are well
    // above the threshold. This simulates the grouping of the small values into
    // the "Other" series.
    final myFakeDesktopData = [
-      new LinearSales(
+      LinearSales(
          random.nextInt(100), (random.nextInt(50) + 50) / 100, makeRadius(6)),
    ];

    final myFakeTabletData = [
-      new LinearSales(
+      LinearSales(
          random.nextInt(100), (random.nextInt(50) + 50) / 100, makeRadius(6)),
    ];

    final myFakeMobileData = [
-      new LinearSales(
+      LinearSales(
          random.nextInt(100), (random.nextInt(50) + 50) / 100, makeRadius(6)),
    ];

    final myFakeChromebookData = [
-      new LinearSales(
+      LinearSales(
          random.nextInt(100), (random.nextInt(50) + 50) / 100, makeRadius(6)),
    ];

    final myFakeHomeData = [
-      new LinearSales(
+      LinearSales(
          random.nextInt(100), (random.nextInt(50) + 50) / 100, makeRadius(6)),
    ];

    // Make sure that the "Other" series values are smaller.
    final myFakeOtherData = [
-      new LinearSales(
-          random.nextInt(100), random.nextInt(50) / 100, makeRadius(6)),
-      new LinearSales(
-          random.nextInt(100), random.nextInt(50) / 100, makeRadius(6)),
-      new LinearSales(
-          random.nextInt(100), random.nextInt(50) / 100, makeRadius(6)),
-      new LinearSales(
-          random.nextInt(100), random.nextInt(50) / 100, makeRadius(6)),
-      new LinearSales(
-          random.nextInt(100), random.nextInt(50) / 100, makeRadius(6)),
-      new LinearSales(
-          random.nextInt(100), random.nextInt(50) / 100, makeRadius(6)),
+      LinearSales(random.nextInt(100), random.nextInt(50) / 100, makeRadius(6)),
+      LinearSales(random.nextInt(100), random.nextInt(50) / 100, makeRadius(6)),
+      LinearSales(random.nextInt(100), random.nextInt(50) / 100, makeRadius(6)),
+      LinearSales(random.nextInt(100), random.nextInt(50) / 100, makeRadius(6)),
+      LinearSales(random.nextInt(100), random.nextInt(50) / 100, makeRadius(6)),
+      LinearSales(random.nextInt(100), random.nextInt(50) / 100, makeRadius(6)),
    ];

    return [
-      new charts.Series<LinearSales, int>(
+      charts.Series<LinearSales, int>(
          id: 'Desktop',
          colorFn: (LinearSales sales, _) =>
              charts.MaterialPalette.blue.shadeDefault,
@@ -107,7 +102,7 @@ class BucketingAxisScatterPlotChart extends StatelessWidget {
          measureFn: (LinearSales sales, _) => sales.revenueShare,
          radiusPxFn: (LinearSales sales, _) => sales.radius,
          data: myFakeDesktopData),
-      new charts.Series<LinearSales, int>(
+      charts.Series<LinearSales, int>(
          id: 'Tablet',
          colorFn: (LinearSales sales, _) =>
              charts.MaterialPalette.red.shadeDefault,
@@ -115,7 +110,7 @@ class BucketingAxisScatterPlotChart extends StatelessWidget {
          measureFn: (LinearSales sales, _) => sales.revenueShare,
          radiusPxFn: (LinearSales sales, _) => sales.radius,
          data: myFakeTabletData),
-      new charts.Series<LinearSales, int>(
+      charts.Series<LinearSales, int>(
          id: 'Mobile',
          colorFn: (LinearSales sales, _) =>
              charts.MaterialPalette.green.shadeDefault,
@@ -123,7 +118,7 @@ class BucketingAxisScatterPlotChart extends StatelessWidget {
          measureFn: (LinearSales sales, _) => sales.revenueShare,
          radiusPxFn: (LinearSales sales, _) => sales.radius,
          data: myFakeMobileData),
-      new charts.Series<LinearSales, int>(
+      charts.Series<LinearSales, int>(
          id: 'Chromebook',
          colorFn: (LinearSales sales, _) =>
              charts.MaterialPalette.purple.shadeDefault,
@@ -131,7 +126,7 @@ class BucketingAxisScatterPlotChart extends StatelessWidget {
          measureFn: (LinearSales sales, _) => sales.revenueShare,
          radiusPxFn: (LinearSales sales, _) => sales.radius,
          data: myFakeChromebookData),
-      new charts.Series<LinearSales, int>(
+      charts.Series<LinearSales, int>(
          id: 'Home',
          colorFn: (LinearSales sales, _) =>
              charts.MaterialPalette.indigo.shadeDefault,
@@ -139,7 +134,7 @@ class BucketingAxisScatterPlotChart extends StatelessWidget {
          measureFn: (LinearSales sales, _) => sales.revenueShare,
          radiusPxFn: (LinearSales sales, _) => sales.radius,
          data: myFakeHomeData),
-      new charts.Series<LinearSales, int>(
+      charts.Series<LinearSales, int>(
          id: 'Other',
          colorFn: (LinearSales sales, _) =>
              charts.MaterialPalette.gray.shadeDefault,
@@ -153,19 +148,19 @@ class BucketingAxisScatterPlotChart extends StatelessWidget {

  @override
  Widget build(BuildContext context) {
-    return new charts.ScatterPlotChart(seriesList,
+    return charts.ScatterPlotChart(seriesList,
        // Set up a bucketing axis that will place all values below 0.1 (10%)
        // into a bucket at the bottom of the chart.
        //
        // Configure a tick count of 3 so that we get 100%, 50%, and the
        // threshold.
-        primaryMeasureAxis: new charts.BucketingAxisSpec(
+        primaryMeasureAxis: charts.BucketingAxisSpec(
            threshold: 0.1,
-            tickProviderSpec: new charts.BucketingNumericTickProviderSpec(
+            tickProviderSpec: const charts.BucketingNumericTickProviderSpec(
                desiredTickCount: 3)),
        // Add a series legend to display the series names.
        behaviors: [
-          new charts.SeriesLegend(position: charts.BehaviorPosition.end),
+          charts.SeriesLegend(position: charts.BehaviorPosition.end),
        ],
        animate: animate);
  }
@@ -173,36 +168,36 @@ class BucketingAxisScatterPlotChart extends StatelessWidget {
  /// Create one series with sample hard coded data.
  static List<charts.Series<LinearSales, int>> _createSampleData() {
    final myFakeDesktopData = [
-      new LinearSales(52, 0.75, 14.0),
+      LinearSales(52, 0.75, 14.0),
    ];

    final myFakeTabletData = [
-      new LinearSales(45, 0.3, 18.0),
+      LinearSales(45, 0.3, 18.0),
    ];

    final myFakeMobileData = [
-      new LinearSales(56, 0.8, 17.0),
+      LinearSales(56, 0.8, 17.0),
    ];

    final myFakeChromebookData = [
-      new LinearSales(25, 0.6, 13.0),
+      LinearSales(25, 0.6, 13.0),
    ];

    final myFakeHomeData = [
-      new LinearSales(34, 0.5, 15.0),
+      LinearSales(34, 0.5, 15.0),
    ];

    final myFakeOtherData = [
-      new LinearSales(10, 0.25, 15.0),
-      new LinearSales(12, 0.075, 14.0),
-      new LinearSales(13, 0.225, 15.0),
-      new LinearSales(16, 0.03, 14.0),
-      new LinearSales(24, 0.04, 13.0),
-      new LinearSales(37, 0.1, 14.5),
+      LinearSales(10, 0.25, 15.0),
+      LinearSales(12, 0.075, 14.0),
+      LinearSales(13, 0.225, 15.0),
+      LinearSales(16, 0.03, 14.0),
+      LinearSales(24, 0.04, 13.0),
+      LinearSales(37, 0.1, 14.5),
    ];

    return [
-      new charts.Series<LinearSales, int>(
+      charts.Series<LinearSales, int>(
          id: 'Desktop',
          colorFn: (LinearSales sales, _) =>
              charts.MaterialPalette.blue.shadeDefault,
@@ -210,7 +205,7 @@ class BucketingAxisScatterPlotChart extends StatelessWidget {
          measureFn: (LinearSales sales, _) => sales.revenueShare,
          radiusPxFn: (LinearSales sales, _) => sales.radius,
          data: myFakeDesktopData),
-      new charts.Series<LinearSales, int>(
+      charts.Series<LinearSales, int>(
          id: 'Tablet',
          colorFn: (LinearSales sales, _) =>
              charts.MaterialPalette.red.shadeDefault,
@@ -218,7 +213,7 @@ class BucketingAxisScatterPlotChart extends StatelessWidget {
          measureFn: (LinearSales sales, _) => sales.revenueShare,
          radiusPxFn: (LinearSales sales, _) => sales.radius,
          data: myFakeTabletData),
-      new charts.Series<LinearSales, int>(
+      charts.Series<LinearSales, int>(
          id: 'Mobile',
          colorFn: (LinearSales sales, _) =>
              charts.MaterialPalette.green.shadeDefault,
@@ -226,7 +221,7 @@ class BucketingAxisScatterPlotChart extends StatelessWidget {
          measureFn: (LinearSales sales, _) => sales.revenueShare,
          radiusPxFn: (LinearSales sales, _) => sales.radius,
          data: myFakeMobileData),
-      new charts.Series<LinearSales, int>(
+      charts.Series<LinearSales, int>(
          id: 'Chromebook',
          colorFn: (LinearSales sales, _) =>
              charts.MaterialPalette.purple.shadeDefault,
@@ -234,7 +229,7 @@ class BucketingAxisScatterPlotChart extends StatelessWidget {
          measureFn: (LinearSales sales, _) => sales.revenueShare,
          radiusPxFn: (LinearSales sales, _) => sales.radius,
          data: myFakeChromebookData),
-      new charts.Series<LinearSales, int>(
+      charts.Series<LinearSales, int>(
          id: 'Home',
          colorFn: (LinearSales sales, _) =>
              charts.MaterialPalette.indigo.shadeDefault,
@@ -242,7 +237,7 @@ class BucketingAxisScatterPlotChart extends StatelessWidget {
          measureFn: (LinearSales sales, _) => sales.revenueShare,
          radiusPxFn: (LinearSales sales, _) => sales.radius,
          data: myFakeHomeData),
-      new charts.Series<LinearSales, int>(
+      charts.Series<LinearSales, int>(
          id: 'Other',
          colorFn: (LinearSales sales, _) =>
              charts.MaterialPalette.gray.shadeDefault,
--- a/web/charts/lib/scatter_plot_chart/comparison_points.dart
+++ b/web/charts/lib/scatter_plot_chart/comparison_points.dart
@@ -24,11 +24,13 @@ class ComparisonPointsScatterPlotChart extends StatelessWidget {
  final List<charts.Series> seriesList;
  final bool animate;

-  ComparisonPointsScatterPlotChart(this.seriesList, {this.animate});
+  const ComparisonPointsScatterPlotChart(this.seriesList,
+      {this.animate, Key key})
+      : super(key: key);

  /// Creates a [ScatterPlotChart] with sample data and no transition.
  factory ComparisonPointsScatterPlotChart.withSampleData() {
-    return new ComparisonPointsScatterPlotChart(
+    return ComparisonPointsScatterPlotChart(
      _createSampleData(),
      // Disable animations for image tests.
      animate: false,
@@ -40,14 +42,14 @@ class ComparisonPointsScatterPlotChart extends StatelessWidget {
  // It is used for creating random series data to demonstrate animation in
  // the example app only.
  factory ComparisonPointsScatterPlotChart.withRandomData() {
-    return new ComparisonPointsScatterPlotChart(_createRandomData());
+    return ComparisonPointsScatterPlotChart(_createRandomData());
  }

  /// Create random data.
  static List<charts.Series<LinearSales, num>> _createRandomData() {
-    final random = new Random();
+    final random = Random();

-    final maxMeasure = 100;
+    const maxMeasure = 100;

    final data = [
      _makeRandomDatum(maxMeasure, random),
@@ -59,7 +61,7 @@ class ComparisonPointsScatterPlotChart extends StatelessWidget {
    ];

    return [
-      new charts.Series<LinearSales, int>(
+      charts.Series<LinearSales, int>(
        id: 'Sales',
        colorFn: (LinearSales sales, _) {
          // Color bucket the measure column value into 3 distinct colors.
@@ -86,7 +88,7 @@ class ComparisonPointsScatterPlotChart extends StatelessWidget {
  }

  static LinearSales _makeRandomDatum(int max, Random random) {
-    final makeRadius = (int value) => (random.nextInt(value) + 6).toDouble();
+    makeRadius(int value) => (random.nextInt(value) + 6).toDouble();

    final year = random.nextInt(max);
    final yearLower = (year * 0.8).round();
@@ -95,37 +97,36 @@ class ComparisonPointsScatterPlotChart extends StatelessWidget {
    final salesLower = (sales * 0.8).round();
    final salesUpper = sales;

-    return new LinearSales(year, yearLower, yearUpper, sales, salesLower,
+    return LinearSales(year, yearLower, yearUpper, sales, salesLower,
        salesUpper, makeRadius(4));
  }
  // EXCLUDE_FROM_GALLERY_DOCS_END

  @override
  Widget build(BuildContext context) {
-    return new charts.ScatterPlotChart(seriesList,
+    return charts.ScatterPlotChart(seriesList,
        animate: animate,
-        defaultRenderer:
-            new charts.PointRendererConfig(pointRendererDecorators: [
-          new charts.ComparisonPointsDecorator(
-              symbolRenderer: new charts.CylinderSymbolRenderer())
+        defaultRenderer: charts.PointRendererConfig(pointRendererDecorators: [
+          charts.ComparisonPointsDecorator(
+              symbolRenderer: charts.CylinderSymbolRenderer())
        ]));
  }

  /// Create one series with sample hard coded data.
  static List<charts.Series<LinearSales, int>> _createSampleData() {
    final data = [
-      new LinearSales(10, 7, 10, 25, 20, 25, 5.0),
-      new LinearSales(13, 11, 13, 225, 205, 225, 5.0),
-      new LinearSales(34, 34, 24, 150, 150, 130, 5.0),
-      new LinearSales(37, 37, 57, 10, 10, 12, 6.5),
-      new LinearSales(45, 35, 45, 260, 300, 260, 8.0),
-      new LinearSales(56, 46, 56, 200, 170, 200, 7.0),
+      LinearSales(10, 7, 10, 25, 20, 25, 5.0),
+      LinearSales(13, 11, 13, 225, 205, 225, 5.0),
+      LinearSales(34, 34, 24, 150, 150, 130, 5.0),
+      LinearSales(37, 37, 57, 10, 10, 12, 6.5),
+      LinearSales(45, 35, 45, 260, 300, 260, 8.0),
+      LinearSales(56, 46, 56, 200, 170, 200, 7.0),
    ];

-    final maxMeasure = 300;
+    const maxMeasure = 300;

    return [
-      new charts.Series<LinearSales, int>(
+      charts.Series<LinearSales, int>(
        id: 'Sales',
        // Providing a color function is optional.
        colorFn: (LinearSales sales, _) {
--- a/web/charts/lib/scatter_plot_chart/scatter_plot_gallery.dart
+++ b/web/charts/lib/scatter_plot_chart/scatter_plot_gallery.dart
@@ -23,36 +23,36 @@ import 'simple.dart';

 List<GalleryScaffold> buildGallery() {
  return [
-    new GalleryScaffold(
-      listTileIcon: new Icon(Icons.scatter_plot),
+    GalleryScaffold(
+      listTileIcon: const Icon(Icons.scatter_plot),
      title: 'Simple Scatter Plot Chart',
      subtitle: 'With a single series',
-      childBuilder: () => new SimpleScatterPlotChart.withRandomData(),
+      childBuilder: () => SimpleScatterPlotChart.withRandomData(),
    ),
-    new GalleryScaffold(
-      listTileIcon: new Icon(Icons.scatter_plot),
+    GalleryScaffold(
+      listTileIcon: const Icon(Icons.scatter_plot),
      title: 'Shapes Scatter Plot Chart',
      subtitle: 'With custom shapes',
-      childBuilder: () => new ShapesScatterPlotChart.withRandomData(),
+      childBuilder: () => ShapesScatterPlotChart.withRandomData(),
    ),
-    new GalleryScaffold(
-      listTileIcon: new Icon(Icons.scatter_plot),
+    GalleryScaffold(
+      listTileIcon: const Icon(Icons.scatter_plot),
      title: 'Comparison Points Scatter Plot Chart',
      subtitle: 'Scatter plot chart with comparison points',
-      childBuilder: () => new ComparisonPointsScatterPlotChart.withRandomData(),
+      childBuilder: () => ComparisonPointsScatterPlotChart.withRandomData(),
    ),
-    new GalleryScaffold(
-      listTileIcon: new Icon(Icons.scatter_plot),
+    GalleryScaffold(
+      listTileIcon: const Icon(Icons.scatter_plot),
      title: 'Pan and Zoom Scatter Plot Chart',
      subtitle: 'Simple scatter plot chart pan and zoom behaviors enabled',
-      childBuilder: () => new ScatterPlotAnimationZoomChart.withRandomData(),
+      childBuilder: () => ScatterPlotAnimationZoomChart.withRandomData(),
    ),
-    new GalleryScaffold(
-      listTileIcon: new Icon(Icons.scatter_plot),
+    GalleryScaffold(
+      listTileIcon: const Icon(Icons.scatter_plot),
      title: 'Bucketing Axis Scatter Plot Chart',
-      subtitle: 'Scatter plot with a measure axis that buckets values less ' +
+      subtitle: 'Scatter plot with a measure axis that buckets values less '
          'than 10% into a single region below the draw area',
-      childBuilder: () => new BucketingAxisScatterPlotChart.withRandomData(),
+      childBuilder: () => BucketingAxisScatterPlotChart.withRandomData(),
    ),
  ];
 }
--- a/web/charts/lib/scatter_plot_chart/shapes.dart
+++ b/web/charts/lib/scatter_plot_chart/shapes.dart
@@ -35,11 +35,12 @@ class ShapesScatterPlotChart extends StatelessWidget {
  final List<charts.Series> seriesList;
  final bool animate;

-  ShapesScatterPlotChart(this.seriesList, {this.animate});
+  const ShapesScatterPlotChart(this.seriesList, {this.animate, Key key})
+      : super(key: key);

  /// Creates a [ScatterPlotChart] with sample data and no transition.
  factory ShapesScatterPlotChart.withSampleData() {
-    return new ShapesScatterPlotChart(
+    return ShapesScatterPlotChart(
      _createSampleData(),
      // Disable animations for image tests.
      animate: false,
@@ -51,49 +52,49 @@ class ShapesScatterPlotChart extends StatelessWidget {
  // It is used for creating random series data to demonstrate animation in
  // the example app only.
  factory ShapesScatterPlotChart.withRandomData() {
-    return new ShapesScatterPlotChart(_createRandomData());
+    return ShapesScatterPlotChart(_createRandomData());
  }

  /// Create random data.
  static List<charts.Series<LinearSales, num>> _createRandomData() {
-    final random = new Random();
+    final random = Random();

-    final makeRadius = (int value) => (random.nextInt(value) + 2).toDouble();
+    makeRadius(int value) => (random.nextInt(value) + 2).toDouble();

    final data = [
-      new LinearSales(random.nextInt(100), random.nextInt(100), makeRadius(6),
+      LinearSales(random.nextInt(100), random.nextInt(100), makeRadius(6),
          'circle', null, null),
-      new LinearSales(random.nextInt(100), random.nextInt(100), makeRadius(6),
-          null, null, null),
-      new LinearSales(random.nextInt(100), random.nextInt(100), makeRadius(6),
-          null, null, null),
+      LinearSales(random.nextInt(100), random.nextInt(100), makeRadius(6), null,
+          null, null),
+      LinearSales(random.nextInt(100), random.nextInt(100), makeRadius(6), null,
+          null, null),
      // Render a hollow circle, filled in with white.
-      new LinearSales(random.nextInt(100), random.nextInt(100),
-          makeRadius(4) + 4, 'circle', charts.MaterialPalette.white, 2.0),
-      new LinearSales(random.nextInt(100), random.nextInt(100), makeRadius(6),
-          null, null, null),
-      new LinearSales(random.nextInt(100), random.nextInt(100), makeRadius(6),
-          null, null, null),
-      new LinearSales(random.nextInt(100), random.nextInt(100), makeRadius(6),
+      LinearSales(random.nextInt(100), random.nextInt(100), makeRadius(4) + 4,
+          'circle', charts.MaterialPalette.white, 2.0),
+      LinearSales(random.nextInt(100), random.nextInt(100), makeRadius(6), null,
+          null, null),
+      LinearSales(random.nextInt(100), random.nextInt(100), makeRadius(6), null,
+          null, null),
+      LinearSales(random.nextInt(100), random.nextInt(100), makeRadius(6),
          'circle', null, null),
-      new LinearSales(random.nextInt(100), random.nextInt(100), makeRadius(6),
-          null, null, null),
-      new LinearSales(random.nextInt(100), random.nextInt(100), makeRadius(6),
-          null, null, null),
+      LinearSales(random.nextInt(100), random.nextInt(100), makeRadius(6), null,
+          null, null),
+      LinearSales(random.nextInt(100), random.nextInt(100), makeRadius(6), null,
+          null, null),
      // Render a hollow circle, filled in with white.
-      new LinearSales(random.nextInt(100), random.nextInt(100),
-          makeRadius(4) + 4, 'circle', charts.MaterialPalette.white, 2.0),
-      new LinearSales(random.nextInt(100), random.nextInt(100), makeRadius(6),
-          null, null, null),
+      LinearSales(random.nextInt(100), random.nextInt(100), makeRadius(4) + 4,
+          'circle', charts.MaterialPalette.white, 2.0),
+      LinearSales(random.nextInt(100), random.nextInt(100), makeRadius(6), null,
+          null, null),
      // Render a hollow square, filled in with white.
-      new LinearSales(random.nextInt(100), random.nextInt(100),
-          makeRadius(4) + 4, null, charts.MaterialPalette.white, 2.0),
+      LinearSales(random.nextInt(100), random.nextInt(100), makeRadius(4) + 4,
+          null, charts.MaterialPalette.white, 2.0),
    ];

-    final maxMeasure = 100;
+    const maxMeasure = 100;

    return [
-      new charts.Series<LinearSales, int>(
+      charts.Series<LinearSales, int>(
        id: 'Sales',
        colorFn: (LinearSales sales, _) {
          // Color bucket the measure column value into 3 distinct colors.
@@ -125,43 +126,41 @@ class ShapesScatterPlotChart extends StatelessWidget {

  @override
  Widget build(BuildContext context) {
-    return new charts.ScatterPlotChart(seriesList,
+    return charts.ScatterPlotChart(seriesList,
        animate: animate,
        // Configure the point renderer to have a map of custom symbol
        // renderers.
        defaultRenderer:
-            new charts.PointRendererConfig<num>(customSymbolRenderers: {
-          'circle': new charts.CircleSymbolRenderer(),
-          'rect': new charts.RectSymbolRenderer(),
+            charts.PointRendererConfig<num>(customSymbolRenderers: {
+          'circle': charts.CircleSymbolRenderer(),
+          'rect': charts.RectSymbolRenderer(),
        }));
  }

  /// Create one series with sample hard coded data.
  static List<charts.Series<LinearSales, int>> _createSampleData() {
    final data = [
-      new LinearSales(0, 5, 3.0, 'circle', null, null),
-      new LinearSales(10, 25, 5.0, null, null, null),
-      new LinearSales(12, 75, 4.0, null, null, null),
+      LinearSales(0, 5, 3.0, 'circle', null, null),
+      LinearSales(10, 25, 5.0, null, null, null),
+      LinearSales(12, 75, 4.0, null, null, null),
      // Render a hollow circle, filled in with white.
-      new LinearSales(
-          13, 225, 5.0, 'circle', charts.MaterialPalette.white, 2.0),
-      new LinearSales(16, 50, 4.0, null, null, null),
-      new LinearSales(24, 75, 3.0, null, null, null),
-      new LinearSales(25, 100, 3.0, 'circle', null, null),
-      new LinearSales(34, 150, 5.0, null, null, null),
-      new LinearSales(37, 10, 4.5, null, null, null),
+      LinearSales(13, 225, 5.0, 'circle', charts.MaterialPalette.white, 2.0),
+      LinearSales(16, 50, 4.0, null, null, null),
+      LinearSales(24, 75, 3.0, null, null, null),
+      LinearSales(25, 100, 3.0, 'circle', null, null),
+      LinearSales(34, 150, 5.0, null, null, null),
+      LinearSales(37, 10, 4.5, null, null, null),
      // Render a hollow circle, filled in with white.
-      new LinearSales(
-          45, 300, 8.0, 'circle', charts.MaterialPalette.white, 2.0),
-      new LinearSales(52, 15, 4.0, null, null, null),
+      LinearSales(45, 300, 8.0, 'circle', charts.MaterialPalette.white, 2.0),
+      LinearSales(52, 15, 4.0, null, null, null),
      // Render a hollow square, filled in with white.
-      new LinearSales(56, 200, 7.0, null, charts.MaterialPalette.white, 2.0),
+      LinearSales(56, 200, 7.0, null, charts.MaterialPalette.white, 2.0),
    ];

-    final maxMeasure = 300;
+    const maxMeasure = 300;

    return [
-      new charts.Series<LinearSales, int>(
+      charts.Series<LinearSales, int>(
        id: 'Sales',
        // Providing a color function is optional.
        colorFn: (LinearSales sales, _) {
--- a/web/charts/lib/scatter_plot_chart/simple.dart
+++ b/web/charts/lib/scatter_plot_chart/simple.dart
@@ -24,11 +24,12 @@ class SimpleScatterPlotChart extends StatelessWidget {
  final List<charts.Series> seriesList;
  final bool animate;

-  SimpleScatterPlotChart(this.seriesList, {this.animate});
+  const SimpleScatterPlotChart(this.seriesList, {this.animate, Key key})
+      : super(key: key);

  /// Creates a [ScatterPlotChart] with sample data and no transition.
  factory SimpleScatterPlotChart.withSampleData() {
-    return new SimpleScatterPlotChart(
+    return SimpleScatterPlotChart(
      _createSampleData(),
      // Disable animations for image tests.
      animate: false,
@@ -40,34 +41,34 @@ class SimpleScatterPlotChart extends StatelessWidget {
  // It is used for creating random series data to demonstrate animation in
  // the example app only.
  factory SimpleScatterPlotChart.withRandomData() {
-    return new SimpleScatterPlotChart(_createRandomData());
+    return SimpleScatterPlotChart(_createRandomData());
  }

  /// Create random data.
  static List<charts.Series<LinearSales, num>> _createRandomData() {
-    final random = new Random();
+    final random = Random();

-    final makeRadius = (int value) => (random.nextInt(value) + 2).toDouble();
+    makeRadius(int value) => (random.nextInt(value) + 2).toDouble();

    final data = [
-      new LinearSales(random.nextInt(100), random.nextInt(100), makeRadius(6)),
-      new LinearSales(random.nextInt(100), random.nextInt(100), makeRadius(6)),
-      new LinearSales(random.nextInt(100), random.nextInt(100), makeRadius(6)),
-      new LinearSales(random.nextInt(100), random.nextInt(100), makeRadius(6)),
-      new LinearSales(random.nextInt(100), random.nextInt(100), makeRadius(6)),
-      new LinearSales(random.nextInt(100), random.nextInt(100), makeRadius(6)),
-      new LinearSales(random.nextInt(100), random.nextInt(100), makeRadius(6)),
-      new LinearSales(random.nextInt(100), random.nextInt(100), makeRadius(6)),
-      new LinearSales(random.nextInt(100), random.nextInt(100), makeRadius(6)),
-      new LinearSales(random.nextInt(100), random.nextInt(100), makeRadius(6)),
-      new LinearSales(random.nextInt(100), random.nextInt(100), makeRadius(6)),
-      new LinearSales(random.nextInt(100), random.nextInt(100), makeRadius(6)),
+      LinearSales(random.nextInt(100), random.nextInt(100), makeRadius(6)),
+      LinearSales(random.nextInt(100), random.nextInt(100), makeRadius(6)),
+      LinearSales(random.nextInt(100), random.nextInt(100), makeRadius(6)),
+      LinearSales(random.nextInt(100), random.nextInt(100), makeRadius(6)),
+      LinearSales(random.nextInt(100), random.nextInt(100), makeRadius(6)),
+      LinearSales(random.nextInt(100), random.nextInt(100), makeRadius(6)),
+      LinearSales(random.nextInt(100), random.nextInt(100), makeRadius(6)),
+      LinearSales(random.nextInt(100), random.nextInt(100), makeRadius(6)),
+      LinearSales(random.nextInt(100), random.nextInt(100), makeRadius(6)),
+      LinearSales(random.nextInt(100), random.nextInt(100), makeRadius(6)),
+      LinearSales(random.nextInt(100), random.nextInt(100), makeRadius(6)),
+      LinearSales(random.nextInt(100), random.nextInt(100), makeRadius(6)),
    ];

-    final maxMeasure = 100;
+    const maxMeasure = 100;

    return [
-      new charts.Series<LinearSales, int>(
+      charts.Series<LinearSales, int>(
        id: 'Sales',
        colorFn: (LinearSales sales, _) {
          // Color bucket the measure column value into 3 distinct colors.
@@ -92,30 +93,30 @@ class SimpleScatterPlotChart extends StatelessWidget {

  @override
  Widget build(BuildContext context) {
-    return new charts.ScatterPlotChart(seriesList, animate: animate);
+    return charts.ScatterPlotChart(seriesList, animate: animate);
  }

  /// Create one series with sample hard coded data.
  static List<charts.Series<LinearSales, int>> _createSampleData() {
    final data = [
-      new LinearSales(0, 5, 3.0),
-      new LinearSales(10, 25, 5.0),
-      new LinearSales(12, 75, 4.0),
-      new LinearSales(13, 225, 5.0),
-      new LinearSales(16, 50, 4.0),
-      new LinearSales(24, 75, 3.0),
-      new LinearSales(25, 100, 3.0),
-      new LinearSales(34, 150, 5.0),
-      new LinearSales(37, 10, 4.5),
-      new LinearSales(45, 300, 8.0),
-      new LinearSales(52, 15, 4.0),
-      new LinearSales(56, 200, 7.0),
+      LinearSales(0, 5, 3.0),
+      LinearSales(10, 25, 5.0),
+      LinearSales(12, 75, 4.0),
+      LinearSales(13, 225, 5.0),
+      LinearSales(16, 50, 4.0),
+      LinearSales(24, 75, 3.0),
+      LinearSales(25, 100, 3.0),
+      LinearSales(34, 150, 5.0),
+      LinearSales(37, 10, 4.5),
+      LinearSales(45, 300, 8.0),
+      LinearSales(52, 15, 4.0),
+      LinearSales(56, 200, 7.0),
    ];

-    final maxMeasure = 300;
+    const maxMeasure = 300;

    return [
-      new charts.Series<LinearSales, int>(
+      charts.Series<LinearSales, int>(
        id: 'Sales',
        // Providing a color function is optional.
        colorFn: (LinearSales sales, _) {