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="M0.25 9C0.25 5.27208 3.27208 2.25 7 2.25H17C20.7279 2.25 23.75 5.27208 23.75 9V15C23.75 18.7279 20.7279 21.75 17 21.75H7C3.27208 21.75 0.25 18.7279 0.25 15V9ZM6 7.75C6.41421 7.75 6.75 8.08579 6.75 8.5V11.25H9.75V8.5C9.75 8.08579 10.0858 7.75 10.5 7.75C10.9142 7.75 11.25 8.08579 11.25 8.5V15.5C11.25 15.9142 10.9142 16.25 10.5 16.25C10.0858 16.25 9.75 15.9142 9.75 15.5V12.75H6.75V15.5C6.75 15.9142 6.41421 16.25 6 16.25C5.58579 16.25 5.25 15.9142 5.25 15.5V8.5C5.25 8.08579 5.58579 7.75 6 7.75ZM14.75 14.7457V9.25435C15.715 9.26933 16.5157 9.33502 17.1203 9.61718C17.4642 9.77767 17.7273 10.0036 17.9147 10.3408C18.1085 10.6896 18.25 11.21 18.25 12C18.25 12.79 18.1085 13.3105 17.9147 13.6592C17.7273 13.9965 17.4642 14.2224 17.1203 14.3829C16.5157 14.6651 15.715 14.7308 14.75 14.7457ZM19.75 12C19.75 11.04 19.579 10.248 19.2259 9.61237C18.8664 8.96527 18.3483 8.53491 17.7547 8.25791C16.6645 7.74918 15.272 7.74964 14.0961 7.75002L14 7.75004C13.5858 7.75004 13.25 8.08583 13.25 8.50004V15.5C13.25 15.9143 13.5858 16.25 14 16.25L14.0961 16.2501C15.272 16.2505 16.6645 16.2509 17.7547 15.7422C18.3483 15.4652 18.8664 15.0348 19.2259 14.3877C19.579 13.7521 19.75 12.96 19.75 12Z" fill="currentColor"/>
</svg>
''',
      colorFilter:
          color != null ? widgets.ColorFilter.mode(color!, widgets.BlendMode.srcIn) : null,
      width: width,
      height: height,
    );