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 d="M12.5 13L10 17H14L11.5 21" stroke="currentColor" stroke-linecap="round" stroke-linejoin="round"/>
<path d="M4 13.4998L3.51493 13.6211C2.62459 13.8437 2 14.6437 2 15.5614V17.4383C2 18.356 2.62459 19.156 3.51493 19.3786L5.25448 19.8135C5.63317 19.9081 6 19.6217 6 19.2314V13.7683C6 13.378 5.63317 13.0916 5.25448 13.1862L4 13.4998ZM4 13.4998V13C4 8.02944 7.58172 4 12 4C16.4183 4 20 8.02944 20 13V13.5M20 13.5L20.4851 13.6211C21.3754 13.8437 22 14.6437 22 15.5614V17.4383C22 18.356 21.3754 19.156 20.4851 19.3786L18.7455 19.8135C18.3668 19.9081 18 19.6217 18 19.2314V13.7683C18 13.378 18.3668 13.0916 18.7455 13.1862L20 13.5Z" stroke="currentColor" stroke-linecap="round" stroke-linejoin="round"/>
</svg>
''',
      colorFilter:
          color != null ? widgets.ColorFilter.mode(color!, widgets.BlendMode.srcIn) : null,
      width: width,
      height: height,
    );