build method
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" height="24" viewBox="0 0 24 24" stroke-width="1.5" fill="none" xmlns="http://www.w3.org/2000/svg">
<path d="M18 14C19.1046 14 20 13.1046 20 12C20 10.8954 19.1046 10 18 10C16.8954 10 16 10.8954 16 12C16 13.1046 16.8954 14 18 14Z" stroke="currentColor" stroke-linecap="round" stroke-linejoin="round"/>
<path d="M18 7C19.1046 7 20 6.10457 20 5C20 3.89543 19.1046 3 18 3C16.8954 3 16 3.89543 16 5C16 6.10457 16.8954 7 18 7Z" stroke="currentColor" stroke-linecap="round" stroke-linejoin="round"/>
<path d="M3 5L13 5" stroke="currentColor" stroke-linecap="round" stroke-linejoin="round"/>
<path d="M3 12L13 12" stroke="currentColor" stroke-linecap="round" stroke-linejoin="round"/>
<path d="M3 19L13 19" stroke="currentColor" stroke-linecap="round" stroke-linejoin="round"/>
<path d="M16 21.2426L18.1213 19.1213M18.1213 19.1213L20.2426 17M18.1213 19.1213L16 17M18.1213 19.1213L20.2426 21.2426" stroke="currentColor" stroke-linecap="round" stroke-linejoin="round"/>
</svg>
''',
colorFilter:
color != null ? widgets.ColorFilter.mode(color!, widgets.BlendMode.srcIn) : null,
width: width,
height: height,
);