build method

@override Widget build(BuildContext context)

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:

• the fields of the widget, which themselves must not change over time, and
• any ambient state obtained from the context using BuildContext.dependOnInheritedWidgetOfExactType.

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" stroke-width="1.5" height="24" viewBox="0 0 24 24" fill="none" xmlns="http://www.w3.org/2000/svg">
<path d="M21 13C21 17.9706 16.9706 22 12 22C7.02944 22 3 17.9706 3 13C3 8.02944 7.02944 4 12 4" stroke="currentColor"  stroke-linecap="round" stroke-linejoin="round"/>
<path d="M12 4H19.5M19.5 4L17.5 2M19.5 4L17.5 6" stroke="currentColor"  stroke-linecap="round" stroke-linejoin="round"/>
<path d="M9 9L9 16" stroke="currentColor"  stroke-linecap="round" stroke-linejoin="round"/>
<path d="M15 9L13 9C12.4477 9 12 9.44772 12 10L12 11.5C12 12.0523 12.4477 12.5 13 12.5L14 12.5C14.5523 12.5 15 12.9477 15 13.5L15 15C15 15.5523 14.5523 16 14 16L12 16" stroke="currentColor"  stroke-linecap="round" stroke-linejoin="round"/>
</svg>
''',
      colorFilter:
          color != null ? widgets.ColorFilter.mode(color!, widgets.BlendMode.srcIn) : null,
      width: width,
      height: height,
    );