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="M12.4961 19.7165L18.4961 16.2879C18.8077 16.1099 19 15.7785 19 15.4197V9.58032C19 9.22147 18.8077 8.89012 18.4961 8.71208L12.4961 5.28351C12.1887 5.10783 11.8113 5.10783 11.5039 5.28351L5.50386 8.71208C5.19229 8.89012 5 9.22147 5 9.58032V15.4197C5 15.7785 5.19229 16.1099 5.50386 16.2879L11.5039 19.7165C11.8113 19.8922 12.1887 19.8922 12.4961 19.7165Z" stroke="currentColor" stroke-linecap="round" stroke-linejoin="round"/>
<path d="M5.5 9.5L12 13M12 13L18.5 9.5M12 13V19.5" stroke="currentColor" stroke-linecap="round" stroke-linejoin="round"/>
<path d="M3 3.01013L3.01 2.99902" stroke="currentColor" stroke-linecap="round" stroke-linejoin="round"/>
<path d="M3 21.0101L3.01 20.999" stroke="currentColor" stroke-linecap="round" stroke-linejoin="round"/>
<path d="M21 3.01013L21.01 2.99902" stroke="currentColor" stroke-linecap="round" stroke-linejoin="round"/>
<path d="M21 21.0101L21.01 20.999" stroke="currentColor" stroke-linecap="round" stroke-linejoin="round"/>
</svg>
''',
colorFilter:
color != null ? widgets.ColorFilter.mode(color!, widgets.BlendMode.srcIn) : null,
width: width,
height: height,
);