build method

  1. @override
Widget build(
  1. BuildContext context
)
override

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

The framework calls this method when this widget is inserted into the tree in a given BuildContext and when the dependencies of this widget change (e.g., an InheritedWidget referenced by this widget changes). This method can potentially be called in every frame and should not have any side effects beyond building a widget.

The framework replaces the subtree below this widget with the widget returned by this method, either by updating the existing subtree or by removing the subtree and inflating a new subtree, depending on whether the widget returned by this method can update the root of the existing subtree, as determined by calling Widget.canUpdate.

Typically implementations return a newly created constellation of widgets that are configured with information from this widget's constructor and from the given BuildContext.

The given BuildContext contains information about the location in the tree at which this widget is being built. For example, the context provides the set of inherited widgets for this location in the tree. A given widget might be built with multiple different BuildContext arguments over time if the widget is moved around the tree or if the widget is inserted into the tree in multiple places at once.

The implementation of this method must only depend on:

If a widget's build method is to depend on anything else, use a StatefulWidget instead.

See also:

  • StatelessWidget, which contains the discussion on performance considerations.

Implementation

@override
widgets.Widget build(widgets.BuildContext context) => SvgPicture.string(
      '''
<svg width="24" height="24" viewBox="0 0 24 24" stroke-width="1.5" fill="none" xmlns="http://www.w3.org/2000/svg">
<path fill-rule="evenodd" clip-rule="evenodd" d="M12 2.25C15.4148 2.25 18.157 4.93659 19.2445 8.53907L20.6646 7.82902C21.0351 7.64377 21.4856 7.79394 21.6709 8.16443C21.8561 8.53491 21.7059 8.98541 21.3355 9.17066L19.5919 10.0425C19.6958 10.6789 19.75 11.3341 19.75 12C19.75 12.4216 19.7283 12.839 19.6859 13.25H22C22.4142 13.25 22.75 13.5858 22.75 14C22.75 14.4142 22.4142 14.75 22 14.75H19.4347C19.2438 15.5659 18.9699 16.3431 18.6235 17.0629L20.5303 18.9697C20.8232 19.2626 20.8232 19.7374 20.5303 20.0303C20.2374 20.3232 19.7626 20.3232 19.4697 20.0303L17.8463 18.4069C16.4519 20.4331 14.3908 21.75 12 21.75C9.60921 21.75 7.54809 20.4331 6.15371 18.4069L4.53033 20.0303C4.23744 20.3232 3.76256 20.3232 3.46967 20.0303C3.17678 19.7374 3.17678 19.2626 3.46967 18.9697L5.37647 17.0629C5.03008 16.3431 4.7562 15.5659 4.56527 14.75H2C1.58579 14.75 1.25 14.4142 1.25 14C1.25 13.5858 1.58579 13.25 2 13.25H4.31407C4.27174 12.839 4.25 12.4216 4.25 12C4.25 11.3341 4.30423 10.6789 4.40814 10.0425L2.66455 9.17066C2.29406 8.98541 2.1439 8.53491 2.32914 8.16443C2.51438 7.79394 2.96488 7.64377 3.33537 7.82902L4.75547 8.53907C5.84297 4.93659 8.58522 2.25 12 2.25ZM11.25 19C11.25 19.4142 11.5858 19.75 12 19.75C12.4142 19.75 12.75 19.4142 12.75 19V9.73117C14.005 9.6696 15.2088 9.46632 16.1588 9.26042C16.5636 9.17268 16.8207 8.77339 16.7329 8.36857C16.6452 7.96376 16.2459 7.70672 15.8411 7.79445C14.7597 8.02883 13.3718 8.25 12 8.25C10.6281 8.25 9.24022 8.02883 8.15882 7.79445C7.75401 7.70672 7.35472 7.96376 7.26698 8.36857C7.17924 8.77339 7.43629 9.17268 7.8411 9.26042C8.79115 9.46632 9.99494 9.6696 11.25 9.73117V19Z" fill="currentColor"/>
</svg>
''',
      colorFilter:
          color != null ? widgets.ColorFilter.mode(color!, widgets.BlendMode.srcIn) : null,
      width: width,
      height: height,
    );