simple_line_chart

Provides a simple line chart. An opinionated library that focuses on API simplicity.

  • Charts multiple datasets
  • Uses flutter components where text is presented so that font sizes adapt to system preferences
  • Cubic bezier curves
  • Multiple axes
  • Legend
  • Highlighting

Usage

Include a chart as follows:

class LineChartContent extends StatefulWidget {
  @override
  State<StatefulWidget> createState() {
    return _LineChartContentState();
  }
}

class _LineChartContentState extends State<LineChartContent> {
  late final LineChartData data;

  @override
  void initState() {
    super.initState();

    // create a data model
    data = LineChartData(datasets: [
      Dataset(
          label: 'First', dataPoints: _createDataPoints(offsetInDegrees: 90)),
      Dataset(
          label: 'Second', dataPoints: _createDataPoints(offsetInDegrees: 0)),
      Dataset(
          label: 'Third', dataPoints: _createDataPoints(offsetInDegrees: 180))
    ]);
  }

  @override
  Widget build(BuildContext context) {
    return Column(children: [
      Padding(
          padding: EdgeInsets.only(top: 20),
          child: LineChart(
              // chart is styled
              style: LineChartStyle.fromTheme(context),
              seriesHeight: 300,
              // chart has data
              data: data))
    ]);
  }
}

// data points are created on a sine curve here,
// but you can plot any data you like
List<DataPoint> _createDataPoints({required int offsetInDegrees}) {
  List<DataPoint> dataPoints = [];
  final degreesToRadians = (pi / 180);
  for (int x = 0; x < 180; x += 20) {
    final di = (x * 2).toDouble() * degreesToRadians;
    dataPoints.add(DataPoint(
        x: x.toDouble(), y: 100.0 * ((sin(di + offsetInDegrees) + 1.0) / 2.0)));
  }
  return dataPoints;
}

See the example for details.

License

Copyright 2021 David Green

Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:

  1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.

  2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.

  3. Neither the name of the copyright holder nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

Libraries

simple_line_chart