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" stroke-width="1.5" viewBox="0 0 24 24" fill="none" xmlns="http://www.w3.org/2000/svg">
<path d="M2 14C2 16.2091 3.79086 18 6 18C8.20914 18 10 16.2091 10 14C10 11.7909 8.20914 10 6 10C3.79086 10 2 11.7909 2 14ZM2 14V6" stroke="currentColor" stroke-linecap="round" stroke-linejoin="round"/>
<path d="M22 14C22 16.2091 20.2091 18 18 18C15.7909 18 14 16.2091 14 14C14 11.7909 15.7909 10 18 10C20.2091 10 22 11.7909 22 14ZM22 14V6" stroke="currentColor" stroke-linecap="round" stroke-linejoin="round"/>
<path d="M14 14H10" stroke="currentColor" stroke-linecap="round" stroke-linejoin="round"/>
</svg>
''',
      colorFilter:
          color != null ? widgets.ColorFilter.mode(color!, widgets.BlendMode.srcIn) : null,
      width: width,
      height: height,
    );