build method

@override Widget build(BuildContext context)

Describes the part of the user interface represented by this widget.

The framework calls this method in a number of different situations. For example:

• After calling initState.
• After calling didUpdateWidget.
• After receiving a call to setState.
• After a dependency of this State object changes.

Here it is called whenever the user interaction is performed and it removes the old widget and updates a chart with a new widget in SfCircularChart.

Implementation

@override
Widget build(BuildContext context) {
  _initialRender = (_widgetNeedUpdate && !_isLegendToggled)
      ? _needExplodeAll
      : (_initialRender == null);
  _prevSize = _prevSize ?? MediaQuery.of(context).size;
  _didSizeChange = _prevSize != MediaQuery.of(context).size;
  _prevSize = MediaQuery.of(context).size;
  _oldDeviceOrientation = _oldDeviceOrientation == null
      ? MediaQuery.of(context).orientation
      : _deviceOrientation;
  _deviceOrientation = MediaQuery.of(context).orientation;
  return RepaintBoundary(
      child: _ChartContainer(
    child: GestureDetector(
        child: Container(
      decoration: BoxDecoration(
          color:
              widget.backgroundColor ?? _chartTheme.plotAreaBackgroundColor,
          image: widget.backgroundImage != null
              ? DecorationImage(
                  image: widget.backgroundImage!, fit: BoxFit.fill)
              : null,
          border: Border.all(
              color: widget.borderColor, width: widget.borderWidth)),
      child: Column(
        children: <Widget>[_renderChartTitle(this), _renderChartElements()],
      ),
    )),
  ));
}