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="M15 12C15 10.3431 16.3431 9 18 9H30C31.6569 9 33 10.3431 33 12C33 13.6569 31.6569 15 30 15H21V21H30C31.6569 21 33 22.3431 33 24C33 25.6569 31.6569 27 30 27H21V33H30C31.6569 33 33 34.3431 33 36C33 37.6569 31.6569 39 30 39H18C16.3431 39 15 37.6569 15 36V12ZM18 11C17.4477 11 17 11.4477 17 12V36C17 36.5523 17.4477 37 18 37H30C30.5523 37 31 36.5523 31 36C31 35.4477 30.5523 35 30 35H20C19.4477 35 19 34.5523 19 34V26C19 25.4477 19.4477 25 20 25H30C30.5523 25 31 24.5523 31 24C31 23.4477 30.5523 23 30 23H20C19.4477 23 19 22.5523 19 22V14C19 13.4477 19.4477 13 20 13H30C30.5523 13 31 12.5523 31 12C31 11.4477 30.5523 11 30 11H18Z" fill="black"/>
</svg>
''',
      colorFilter:
          color != null ? widgets.ColorFilter.mode(color!, widgets.BlendMode.srcIn) : null,
      width: width,
      height: height,
    );