ShaderBuilder class

A widget that loads and caches FragmentPrograms based on the asset key.

Usage of this widget avoids the need for a user authored stateful widget for managing the lifecycle of loading a shader. Once a shader is cached, subsequent usages of it via a ShaderBuilder will always be available synchronously. These shaders can also be precached imperatively with ShaderBuilder.precacheShader.

If the shader is not yet loaded, the provided child widget or a SizedBox is returned instead of invoking the builder callback.

Example: providing access to a FragmentShader instance.

Widget build(BuildContext context) {
 return ShaderBuilder(
   builder: (BuildContext context, ui.FragmentShader shader, Widget? child) {
     return WidgetThatUsesFragmentShader(
       shader: shader,
       child: child,
     );
   },
   child: Text('Hello, Shader'),
 );
}

Inheritance

Constructors

ShaderBuilder(ShaderBuilderCallback builder, {Key? key, required String assetKey, Widget? child}): Create a new ShaderBuilder.
const

Properties

assetKey → String: The asset key used to a lookup a shader.
final
builder → ShaderBuilderCallback: The builder that provides access to a FragmentShader.
final
child → Widget?: The child widget to pass through to the builder, optional.
final
hashCode → int: The hash code for this object.
no setterinherited
key → Key?: Controls how one widget replaces another widget in the tree.
finalinherited
runtimeType → Type: A representation of the runtime type of the object.
no setterinherited

Methods

createElement() → StatefulElement: Creates a StatefulElement to manage this widget's location in the tree.
inherited
createState() → State<StatefulWidget>: Creates the mutable state for this widget at a given location in the tree.
override
debugDescribeChildren() → List<DiagnosticsNode>: Returns a list of DiagnosticsNode objects describing this node's children.
inherited
debugFillProperties(DiagnosticPropertiesBuilder properties) → void: Add additional properties associated with the node.
inherited
noSuchMethod(Invocation invocation) → dynamic: Invoked when a nonexistent method or property is accessed.
inherited
toDiagnosticsNode({String? name, DiagnosticsTreeStyle? style}) → DiagnosticsNode: Returns a debug representation of the object that is used by debugging tools and by DiagnosticsNode.toStringDeep.
inherited
toString({DiagnosticLevel minLevel = DiagnosticLevel.info}) → String: A string representation of this object.
inherited
toStringDeep({String prefixLineOne = '', String? prefixOtherLines, DiagnosticLevel minLevel = DiagnosticLevel.debug}) → String: Returns a string representation of this node and its descendants.
inherited
toStringShallow({String joiner = ', ', DiagnosticLevel minLevel = DiagnosticLevel.debug}) → String: Returns a one-line detailed description of the object.
inherited
toStringShort() → String: A short, textual description of this widget.
inherited

Operators

operator ==(Object other) → bool: The equality operator.
inherited

Static Methods

precacheShader(String assetKey) → Future<void>: Precache a FragmentProgram based on its assetKey.