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 21V17C12 14.2386 9.76142 12 7 12H3" stroke="currentColor" stroke-linecap="round" stroke-linejoin="round"/>
<path d="M12 21V17C12 14.2386 14.2386 12 17 12H21" stroke="currentColor" stroke-linecap="round" stroke-linejoin="round"/>
<path d="M12 2.00005V22" stroke="currentColor" stroke-linecap="round" stroke-linejoin="round"/>
<path d="M6 8C4.4379 9.5621 3.5621 10.4379 2 12C3.5621 13.5621 4.4379 14.4379 6 16" stroke="currentColor" stroke-linecap="round" stroke-linejoin="round"/>
<path d="M16 6C14.4379 4.4379 13.5621 3.5621 12 2C10.4379 3.5621 9.5621 4.4379 8 6" stroke="currentColor" stroke-linecap="round" stroke-linejoin="round"/>
<path d="M18 8C19.5621 9.5621 20.4379 10.4379 22 12C20.4379 13.5621 19.5621 14.4379 18 16" stroke="currentColor" stroke-linecap="round" stroke-linejoin="round"/>
</svg>
''',
      colorFilter:
          color != null ? widgets.ColorFilter.mode(color!, widgets.BlendMode.srcIn) : null,
      width: width,
      height: height,
    );