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" fill="none" xmlns="http://www.w3.org/2000/svg">
<path fill-rule="evenodd" clip-rule="evenodd" d="M3.6 2.25C2.85442 2.25 2.25 2.85441 2.25 3.6V20.4C2.25 21.1456 2.85441 21.75 3.6 21.75H20.4C21.1456 21.75 21.75 21.1456 21.75 20.4V3.6C21.75 2.85442 21.1456 2.25 20.4 2.25H3.6ZM10.409 9.34835C10.1161 9.05546 9.64121 9.05546 9.34831 9.34835C9.05542 9.64124 9.05542 10.1161 9.34831 10.409L10.9393 12L9.34831 13.591C9.05542 13.8839 9.05542 14.3588 9.34831 14.6517C9.64121 14.9445 10.1161 14.9445 10.409 14.6517L12 13.0607L13.591 14.6517C13.8838 14.9445 14.3587 14.9445 14.6516 14.6517C14.9445 14.3588 14.9445 13.8839 14.6516 13.591L13.0606 12L14.6516 10.409C14.9445 10.1161 14.9445 9.64124 14.6516 9.34835C14.3587 9.05546 13.8838 9.05546 13.591 9.34835L12 10.9393L10.409 9.34835Z" fill="currentColor"/>
</svg>
''',
      colorFilter:
          color != null ? widgets.ColorFilter.mode(color!, widgets.BlendMode.srcIn) : null,
      width: width,
      height: height,
    );