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" stroke-width="1.5" viewBox="0 0 24 24" fill="none" xmlns="http://www.w3.org/2000/svg">
<path d="M12 5C14.9952 5 19.2354 5.69203 20.5764 5.92472C20.8312 5.96893 21.0235 6.17124 21.056 6.42778C21.1866 7.45584 21.5 10.1194 21.5 12C21.5 13.8806 21.1866 16.5442 21.056 17.5722C21.0235 17.8288 20.8312 18.0311 20.5764 18.0753C19.2354 18.308 14.9952 19 12 19C9.00483 19 4.76463 18.308 3.4236 18.0753C3.16881 18.0311 2.97653 17.8288 2.94395 17.5722C2.81339 16.5442 2.5 13.8806 2.5 12C2.5 10.1194 2.81339 7.45584 2.94395 6.42778C2.97653 6.17124 3.16882 5.96892 3.42361 5.92472C4.76463 5.69203 9.00483 5 12 5Z" stroke="currentColor" stroke-linecap="round" stroke-linejoin="round"/>
</svg>
''',
      colorFilter:
          color != null ? widgets.ColorFilter.mode(color!, widgets.BlendMode.srcIn) : null,
      width: width,
      height: height,
    );