samples/web/charts/lib/axes/nonzero_bound_measure_axis.dart

// 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.

/// Example of timeseries chart that has a measure axis that does NOT include
/// zero. It starts at 100 and goes to 140.
// EXCLUDE_FROM_GALLERY_DOCS_START
import 'dart:math';
// EXCLUDE_FROM_GALLERY_DOCS_END
import 'package:charts_flutter/flutter.dart' as charts;
import 'package:flutter/material.dart';

class NonzeroBoundMeasureAxis extends StatelessWidget {
  final List<charts.Series> seriesList;
  final bool animate;

  NonzeroBoundMeasureAxis(this.seriesList, {this.animate});

  /// Creates a [TimeSeriesChart] with sample data and no transition.
  factory NonzeroBoundMeasureAxis.withSampleData() {
    return new NonzeroBoundMeasureAxis(
      _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 NonzeroBoundMeasureAxis.withRandomData() {
    return new NonzeroBoundMeasureAxis(_createRandomData());
  }

  /// Create random data.
  static List<charts.Series<MyRow, DateTime>> _createRandomData() {
    final random = new Random();

    final data = [
      new MyRow(new DateTime(2017, 9, 25), random.nextInt(100) + 100),
      new MyRow(new DateTime(2017, 9, 26), random.nextInt(100) + 100),
      new MyRow(new DateTime(2017, 9, 27), random.nextInt(100) + 100),
      new MyRow(new DateTime(2017, 9, 28), random.nextInt(100) + 100),
      new MyRow(new DateTime(2017, 9, 29), random.nextInt(100) + 100),
      new MyRow(new DateTime(2017, 9, 30), random.nextInt(100) + 100),
      new MyRow(new DateTime(2017, 10, 01), random.nextInt(100) + 100),
      new MyRow(new DateTime(2017, 10, 02), random.nextInt(100) + 100),
      new MyRow(new DateTime(2017, 10, 03), random.nextInt(100) + 100),
      new MyRow(new DateTime(2017, 10, 04), random.nextInt(100) + 100),
      new MyRow(new DateTime(2017, 10, 05), random.nextInt(100) + 100),
    ];

    return [
      new charts.Series<MyRow, DateTime>(
        id: 'Headcount',
        domainFn: (MyRow row, _) => row.timeStamp,
        measureFn: (MyRow row, _) => row.headcount,
        data: data,
      )
    ];
  }
  // EXCLUDE_FROM_GALLERY_DOCS_END

  @override
  Widget build(BuildContext context) {
    return new charts.TimeSeriesChart(seriesList,
        animate: animate,
        // Provide a tickProviderSpec which does NOT require that zero is
        // included.
        primaryMeasureAxis: new charts.NumericAxisSpec(
            tickProviderSpec:
                new charts.BasicNumericTickProviderSpec(zeroBound: false)));
  }

  /// Create one series with sample hard coded data.
  static List<charts.Series<MyRow, DateTime>> _createSampleData() {
    final data = [
      new MyRow(new DateTime(2017, 9, 25), 106),
      new MyRow(new DateTime(2017, 9, 26), 108),
      new MyRow(new DateTime(2017, 9, 27), 106),
      new MyRow(new DateTime(2017, 9, 28), 109),
      new MyRow(new DateTime(2017, 9, 29), 111),
      new MyRow(new DateTime(2017, 9, 30), 115),
      new MyRow(new DateTime(2017, 10, 01), 125),
      new MyRow(new DateTime(2017, 10, 02), 133),
      new MyRow(new DateTime(2017, 10, 03), 127),
      new MyRow(new DateTime(2017, 10, 04), 131),
      new MyRow(new DateTime(2017, 10, 05), 123),
    ];

    return [
      new charts.Series<MyRow, DateTime>(
        id: 'Headcount',
        domainFn: (MyRow row, _) => row.timeStamp,
        measureFn: (MyRow row, _) => row.headcount,
        data: data,
      )
    ];
  }
}

/// Sample time series data type.
class MyRow {
  final DateTime timeStamp;
  final int headcount;
  MyRow(this.timeStamp, this.headcount);
}