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="M2.6 4H8.77805C8.92127 4 9.05977 4.05124 9.16852 4.14445L12.3315 6.85555C12.4402 6.94876 12.5787 7 12.722 7H21.4C21.7314 7 22 7.26863 22 7.6V10.4C22 10.7314 21.7314 11 21.4 11H2.6C2.26863 11 2 10.7314 2 10.4V4.6C2 4.26863 2.26863 4 2.6 4Z" stroke="currentColor" stroke-linecap="round" stroke-linejoin="round"/>
<path d="M22 10L22 14" stroke="currentColor" stroke-linecap="round" stroke-linejoin="round"/>
<path d="M2 10V19.4C2 19.7314 2.26863 20 2.6 20H13" stroke="currentColor" stroke-linecap="round" stroke-linejoin="round"/>
<path d="M19 21C20.1046 21 21 20.1046 21 19C21 17.8954 20.1046 17 19 17C18.6357 17 18.2942 17.0974 18 17.2676C17.4022 17.6134 17 18.2597 17 19C17 19.7403 17.4022 20.3866 18 20.7324C18.2942 20.9026 18.6357 21 19 21Z" stroke="currentColor" stroke-linecap="round" stroke-linejoin="round"/>
<path d="M19 22C20.6569 22 22 20.6569 22 19C22 17.3431 20.6569 16 19 16C17.3431 16 16 17.3431 16 19C16 20.6569 17.3431 22 19 22Z" stroke="currentColor" stroke-linecap="round" stroke-linejoin="round" stroke-dasharray="0.3 2"/>
</svg>
''',
colorFilter:
color != null ? widgets.ColorFilter.mode(color!, widgets.BlendMode.srcIn) : null,
width: width,
height: height,
);