Bezier Chart

A beautiful bezier line chart widget for flutter that is highly interactive and configurable.

Features

Multi bezier lines
Allow numbers and datetimes
Gestures support like touch, pinch/zoom, scrolling
Highly customizable

Instructions

Long press and drag to display the indicator
Tap to dismiss the indicator
When using chart Scale different from Custom, you can change between WEEKLY, MONTHLY, YEARLY using pinch/zoom when the indicator is not visible.

Getting started

You should ensure that you add the dependency in your flutter project.

dependencies:
  bezier_chart: "^1.0.16"

You should then run flutter packages upgrade or update your packages in IntelliJ.

Example Project

There is a example project in the example folder. Check it out. Otherwise, keep reading to get up and running.

Usage

Custom Numbers

  Widget sample1(BuildContext context) {
  return Center(
    child: Container(
      color: Colors.red,
      height: MediaQuery.of(context).size.height / 2,
      width: MediaQuery.of(context).size.width * 0.9,
      child: BezierChart(
        bezierChartScale: BezierChartScale.CUSTOM,
        xAxisCustomValues: const [0, 5, 10, 15, 20, 25, 30, 35],
        series: const [
          BezierLine(
            data: const [
              DataPoint<double>(value: 10, xAxis: 0),
              DataPoint<double>(value: 130, xAxis: 5),
              DataPoint<double>(value: 50, xAxis: 10),
              DataPoint<double>(value: 150, xAxis: 15),
              DataPoint<double>(value: 75, xAxis: 20),
              DataPoint<double>(value: 0, xAxis: 25),
              DataPoint<double>(value: 5, xAxis: 30),
              DataPoint<double>(value: 45, xAxis: 35),
            ],
          ),
        ],
        config: BezierChartConfig(
          verticalIndicatorStrokeWidth: 3.0,
          verticalIndicatorColor: Colors.black26,
          showVerticalIndicator: true,
          backgroundColor: Colors.red,
          snap: false,
        ),
      ),
    ),
  );
}

Custom Numbers multiline

Widget sample2(BuildContext context) {
  return Center(
    child: Container(
      color: Colors.red,
      height: MediaQuery.of(context).size.height / 2,
      width: MediaQuery.of(context).size.width,
      child: BezierChart(
        bezierChartScale: BezierChartScale.CUSTOM,
        xAxisCustomValues: const [0, 3, 10, 15, 20, 25, 30, 35],
        series: const [
          BezierLine(
            label: "Custom 1",
            data: const [
              DataPoint<double>(value: 10, xAxis: 0),
              DataPoint<double>(value: 130, xAxis: 5),
              DataPoint<double>(value: 50, xAxis: 10),
              DataPoint<double>(value: 150, xAxis: 15),
              DataPoint<double>(value: 75, xAxis: 20),
              DataPoint<double>(value: 0, xAxis: 25),
              DataPoint<double>(value: 5, xAxis: 30),
              DataPoint<double>(value: 45, xAxis: 35),
            ],
          ),
          BezierLine(
            lineColor: Colors.blue,
            lineStrokeWidth: 2.0,
            label: "Custom 2",
            data: const [
              DataPoint<double>(value: 5, xAxis: 0),
              DataPoint<double>(value: 50, xAxis: 5),
              DataPoint<double>(value: 30, xAxis: 10),
              DataPoint<double>(value: 30, xAxis: 15),
              DataPoint<double>(value: 50, xAxis: 20),
              DataPoint<double>(value: 40, xAxis: 25),
              DataPoint<double>(value: 10, xAxis: 30),
              DataPoint<double>(value: 30, xAxis: 35),
            ],
          ),
          BezierLine(
            lineColor: Colors.black,
            lineStrokeWidth: 2.0,
            label: "Custom 3",
            data: const [
              DataPoint<double>(value: 5, xAxis: 0),
              DataPoint<double>(value: 10, xAxis: 5),
              DataPoint<double>(value: 35, xAxis: 10),
              DataPoint<double>(value: 40, xAxis: 15),
              DataPoint<double>(value: 40, xAxis: 20),
              DataPoint<double>(value: 40, xAxis: 25),
              DataPoint<double>(value: 9, xAxis: 30),
              DataPoint<double>(value: 11, xAxis: 35),
            ],
          ),
        ],
        config: BezierChartConfig(
          verticalIndicatorStrokeWidth: 2.0,
          verticalIndicatorColor: Colors.black12,
          showVerticalIndicator: true,
          contentWidth: MediaQuery.of(context).size.width * 2,
          backgroundColor: Colors.red,
        ),
      ),
    ),
  );
}

Weekly Chart

Widget sample3(BuildContext context) {
  final fromDate = DateTime(2019, 05, 22);
  final toDate = DateTime.now();

  final date1 = DateTime.now().subtract(Duration(days: 2));
  final date2 = DateTime.now().subtract(Duration(days: 3));

  return Center(
    child: Container(
      color: Colors.red,
      height: MediaQuery.of(context).size.height / 2,
      width: MediaQuery.of(context).size.width,
      child: BezierChart(
        fromDate: fromDate,
        bezierChartScale: BezierChartScale.WEEKLY,
        toDate: toDate,
        selectedDate: toDate,
        series: [
          BezierLine(
            label: "Duty",
            onMissingValue: (dateTime) {
              if (dateTime.day.isEven) {
                return 10.0;
              }
              return 5.0;
            },
            data: [
              DataPoint<DateTime>(value: 10, xAxis: date1),
              DataPoint<DateTime>(value: 50, xAxis: date2),
            ],
          ),
        ],
        config: BezierChartConfig(
          verticalIndicatorStrokeWidth: 3.0,
          verticalIndicatorColor: Colors.black26,
          showVerticalIndicator: true,
          verticalIndicatorFixedPosition: false,
          backgroundColor: Colors.red,
          footerHeight: 30.0,
        ),
      ),
    ),
  );
}

Monthly Chart

Widget sample4(BuildContext context) {
  final fromDate = DateTime(2018, 11, 22);
  final toDate = DateTime.now();

  final date1 = DateTime.now().subtract(Duration(days: 2));
  final date2 = DateTime.now().subtract(Duration(days: 3));

  final date3 = DateTime.now().subtract(Duration(days: 35));
  final date4 = DateTime.now().subtract(Duration(days: 36));

  final date5 = DateTime.now().subtract(Duration(days: 65));
  final date6 = DateTime.now().subtract(Duration(days: 64));

  return Center(
    child: Container(
      color: Colors.red,
      height: MediaQuery.of(context).size.height / 2,
      width: MediaQuery.of(context).size.width,
      child: BezierChart(
        bezierChartScale: BezierChartScale.MONTHLY,
        fromDate: fromDate,
        toDate: toDate,
        selectedDate: toDate,
        series: [
          BezierLine(
            label: "Duty",
            onMissingValue: (dateTime) {
              if (dateTime.month.isEven) {
                return 10.0;
              }
              return 5.0;
            },
            data: [
              DataPoint<DateTime>(value: 10, xAxis: date1),
              DataPoint<DateTime>(value: 50, xAxis: date2),
              DataPoint<DateTime>(value: 20, xAxis: date3),
              DataPoint<DateTime>(value: 80, xAxis: date4),
              DataPoint<DateTime>(value: 14, xAxis: date5),
              DataPoint<DateTime>(value: 30, xAxis: date6),
            ],
          ),
        ],
        config: BezierChartConfig(
          verticalIndicatorStrokeWidth: 3.0,
          verticalIndicatorColor: Colors.black26,
          showVerticalIndicator: true,
          verticalIndicatorFixedPosition: false,
          backgroundColor: Colors.red,
          footerHeight: 30.0,
        ),
      ),
    ),
  );
}

Yearly Chart

Widget sample5(BuildContext context) {
  final fromDate = DateTime(2012, 11, 22);
  final toDate = DateTime.now();

  final date1 = DateTime.now().subtract(Duration(days: 2));
  final date2 = DateTime.now().subtract(Duration(days: 3));

  final date3 = DateTime.now().subtract(Duration(days: 300));
  final date4 = DateTime.now().subtract(Duration(days: 320));

  final date5 = DateTime.now().subtract(Duration(days: 650));
  final date6 = DateTime.now().subtract(Duration(days: 652));

  return Center(
    child: Container(
      color: Colors.red,
      height: MediaQuery.of(context).size.height / 2,
      width: MediaQuery.of(context).size.width,
      child: BezierChart(
        bezierChartScale: BezierChartScale.YEARLY,
        fromDate: fromDate,
        toDate: toDate,
        selectedDate: toDate,
        series: [
          BezierLine(
            label: "Duty",
            onMissingValue: (dateTime) {
              if (dateTime.year.isEven) {
                return 20.0;
              }
              return 5.0;
            },
            data: [
              DataPoint<DateTime>(value: 10, xAxis: date1),
              DataPoint<DateTime>(value: 50, xAxis: date2),
              DataPoint<DateTime>(value: 100, xAxis: date3),
              DataPoint<DateTime>(value: 100, xAxis: date4),
              DataPoint<DateTime>(value: 40, xAxis: date5),
              DataPoint<DateTime>(value: 47, xAxis: date6),
            ],
          ),
          BezierLine(
            label: "Flight",
            lineColor: Colors.black26,
            onMissingValue: (dateTime) {
              if (dateTime.month.isEven) {
                return 10.0;
              }
              return 3.0;
            },
            data: [
              DataPoint<DateTime>(value: 20, xAxis: date1),
              DataPoint<DateTime>(value: 30, xAxis: date2),
              DataPoint<DateTime>(value: 150, xAxis: date3),
              DataPoint<DateTime>(value: 80, xAxis: date4),
              DataPoint<DateTime>(value: 45, xAxis: date5),
              DataPoint<DateTime>(value: 45, xAxis: date6),
            ],
          ),
        ],
        config: BezierChartConfig(
          verticalIndicatorStrokeWidth: 3.0,
          verticalIndicatorColor: Colors.black26,
          showVerticalIndicator: true,
          verticalIndicatorFixedPosition: false,
          backgroundGradient: LinearGradient(
            colors: [
              Colors.red[300],
              Colors.red[400],
              Colors.red[400],
              Colors.red[500],
              Colors.red,
            ],
            begin: Alignment.topCenter,
            end: Alignment.bottomCenter,
          ),
          footerHeight: 30.0,
        ),
      ),
    ),
  );
}

API

In this table, you can find all attributes provided by BezierChartConfig:

Attribute	Default value	Description
showVerticalIndicator	true	`true` if you want to display the vertical indicator
verticalIndicatorColor	Colors.black
verticalIndicatorStrokeWidth	2.0	`width` of the line used for the vertical indicator
verticalIndicatorFixedPosition	false	`true` if you want to keep the info indicator in a fixed position
verticalLineFullHeight		`true` if you want to display the vertical line in full height
bubbleIndicatorColor	Colors.white	Color of the bubble indicator, it’s white by default
bubbleIndicatorTitleStyle	const TextStyle()	TextStyle for the title displayed inside the bubble indicator
bubbleIndicatorValueStyle	const TextStyle()	TextStyle for the value displayed inside the bubble indicator
bubbleIndicatorValueFormat	`null`	NumberFormat for the value displayed inside the bubble indicator
bubbleIndicatorLabelStyle	const TextStyle()	TextStyle for the label displayed inside the bubble indicator
backgroundColor	Colors.transparent	Color of the background of the chart
backgroundGradient		Gradient of the background of the chart
displayYAxis	false	`true` if you want to display the value of the Y axis, [false] by default
stepsYAxis		If [displayYAxis] is true, then you can set a positive value to display the steps of Y axis values. e.g 1: stepsYAxis : 5 , if your maxValue is 100, then the Y values should be: [0,5,10,15 …. 100] e.g 2: stepsYAxis : 10 , if your maxValue is 100, then the Y values should be: [10,20,30,40 …. 100]
startYAxisFromNonZeroValue	true	`true` if you want to start the values of Y axis from the minimum value of your Y values
yAxisTextStyle		TextStyle of the text of the Y Axis values
xAxisTextStyle		TextStyle of the text of the X Axis values
footerHeight	35.0	Height of the footer
showDataPoints	true	`true` if you want to display the data points
snap	true	`true` if you want to snap between each data point
pinchZoom	true	`true` if you want to enable pinch Zoom for `bezierChartScale` of date types Pinch and zoom is used to switch beetwen charts of date types
contentWidth		If the `contentWidth` is upper than the current width then the content will be scrollable (only valid for `bezierChartScale` = `CUSTOM`)
displayLinesXAxis	false	`true` if you want to display a vertical line on each X data point, it only works when there is one `BezierLine`
xLinesColor	Colors.grey	Color for the vertical line in each X point, only works when `displayLinesXAxis` is true
displayDataPointWhenNoValue	true	`true` if you want do display the dot when there is no value specified (The values inside `onMissingValue`)
physics	const AlwaysScrollableScrollPhysics()	The physics for horizontal ScrollView
updatePositionOnTap	false	`true` if you want do update bubble info on tap action instead of long press. This option will disable tap to hide bubble action