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="M20.4 21.75C21.1456 21.75 21.75 21.1456 21.75 20.4V3.6C21.75 2.85442 21.1456 2.25 20.4 2.25H3.6C2.85442 2.25 2.25 2.85441 2.25 3.6V20.4C2.25 21.1456 2.85441 21.75 3.6 21.75H20.4ZM14.1216 15.5786H9.17188C8.97993 15.5786 8.78799 15.5054 8.64155 15.3589C8.56964 15.287 8.51538 15.2042 8.47878 15.1157C8.44211 15.0273 8.42188 14.9303 8.42188 14.8286V9.87883C8.42188 9.46462 8.75766 9.12883 9.17188 9.12883C9.58609 9.12883 9.92188 9.46462 9.92188 9.87883V13.018L14.2984 8.6414C14.5913 8.34851 15.0662 8.34851 15.3591 8.6414C15.652 8.9343 15.652 9.40917 15.3591 9.70206L10.9825 14.0786H14.1216C14.5359 14.0786 14.8716 14.4144 14.8716 14.8286C14.8716 15.2428 14.5359 15.5786 14.1216 15.5786Z" fill="currentColor"/>
</svg>
''',
      colorFilter:
          color != null ? widgets.ColorFilter.mode(color!, widgets.BlendMode.srcIn) : null,
      width: width,
      height: height,
    );