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="M6 3H3V6" stroke="currentColor" stroke-linecap="round" stroke-linejoin="round"/>
<path d="M18 3H21V6" stroke="currentColor" stroke-linecap="round" stroke-linejoin="round"/>
<path d="M6 21H3V18" stroke="currentColor" stroke-linecap="round" stroke-linejoin="round"/>
<path d="M18 21H21V18" stroke="currentColor" stroke-linecap="round" stroke-linejoin="round"/>
<path d="M12.5145 17.6913L16.5145 15.2913C16.8157 15.1106 17 14.7851 17 14.4338V10.5662C17 10.2149 16.8157 9.88942 16.5145 9.7087L12.5145 7.3087C12.1978 7.11869 11.8022 7.11869 11.4855 7.3087L7.4855 9.7087C7.1843 9.88942 7 10.2149 7 10.5662V14.4338C7 14.7851 7.1843 15.1106 7.4855 15.2913L11.4855 17.6913C11.8022 17.8813 12.1978 17.8813 12.5145 17.6913Z" stroke="currentColor" stroke-linecap="round" stroke-linejoin="round"/>
<path d="M7.5 10.5L12 12.9995M12 12.9995C12 12.9995 15.7637 10.9492 16.5 10.5M12 12.9995V17.5" stroke="currentColor" stroke-linecap="round" stroke-linejoin="round"/>
</svg>
''',
      colorFilter:
          color != null ? widgets.ColorFilter.mode(color!, widgets.BlendMode.srcIn) : null,
      width: width,
      height: height,
    );