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="48" height="48" viewBox="0 0 48 48" fill="none" xmlns="http://www.w3.org/2000/svg">
<path fill-rule="evenodd" clip-rule="evenodd" d="M20 4C18.3431 4 17 5.34315 17 7H13C11.3431 7 10 8.34315 10 10V20.9886H17.6326L21.0207 14.9654L23.1377 22.375L25.7284 19.0442H31.2175C31.7698 19.0442 32.2175 19.4919 32.2175 20.0442C32.2175 20.5965 31.7698 21.0442 31.2175 21.0442H26.7066L22.2972 26.7133L20.4143 20.123L18.8023 22.9886H10V41C10 42.6569 11.3431 44 13 44H35C36.6569 44 38 42.6569 38 41V10C38 8.34315 36.6569 7 35 7H31C31 5.34315 29.6569 4 28 4H20ZM19 7C19 6.44772 19.4477 6 20 6H28C28.5523 6 29 6.44772 29 7V9C29 9.55228 28.5523 10 28 10H20C19.4477 10 19 9.55228 19 9V7ZM16 31C16 30.4477 16.4477 30 17 30H31C31.5523 30 32 30.4477 32 31C32 31.5523 31.5523 32 31 32H17C16.4477 32 16 31.5523 16 31ZM17 36C16.4477 36 16 36.4477 16 37C16 37.5523 16.4477 38 17 38H23C23.5523 38 24 37.5523 24 37C24 36.4477 23.5523 36 23 36H17Z" fill="black"/>
</svg>
''',
      colorFilter:
          color != null ? widgets.ColorFilter.mode(color!, widgets.BlendMode.srcIn) : null,
      width: width,
      height: height,
    );