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" stroke-width="1.5" viewBox="0 0 24 24" fill="none" xmlns="http://www.w3.org/2000/svg">
<path d="M19.5 22C20.3284 22 21 21.3284 21 20.5C21 19.6716 20.3284 19 19.5 19C18.6716 19 18 19.6716 18 20.5C18 21.3284 18.6716 22 19.5 22Z" fill="currentColor" stroke="currentColor" stroke-linecap="round" stroke-linejoin="round"/>
<path d="M9.5 22C10.3284 22 11 21.3284 11 20.5C11 19.6716 10.3284 19 9.5 19C8.67157 19 8 19.6716 8 20.5C8 21.3284 8.67157 22 9.5 22Z" fill="currentColor" stroke="currentColor" stroke-linecap="round" stroke-linejoin="round"/>
<path d="M5 4H22L20 15H7L5 4ZM5 4C4.83333 3.33333 4 2 2 2" stroke="currentColor" stroke-linecap="round" stroke-linejoin="round"/>
<path d="M20 15H7H5.23077C3.44646 15 2.5 15.7812 2.5 17C2.5 18.2188 3.44646 19 5.23077 19H19.5" stroke="currentColor" stroke-linecap="round" stroke-linejoin="round"/>
</svg>
''',
colorFilter:
color != null ? widgets.ColorFilter.mode(color!, widgets.BlendMode.srcIn) : null,
width: width,
height: height,
);