RenderObjectWidget class - widgets library (original) (raw)

RenderObjectWidgets provide the configuration for RenderObjectElements, which wrap RenderObjects, which provide the actual rendering of the application.

Usually, rather than subclassing RenderObjectWidget directly, render object widgets subclass one of:

• LeafRenderObjectWidget, if the widget has no children.
• SingleChildRenderObjectWidget, if the widget has exactly one child.
• MultiChildRenderObjectWidget, if the widget takes a list of children.
• SlottedMultiChildRenderObjectWidget, if the widget organizes its children in different named slots.

Subclasses must implement createRenderObject and updateRenderObject.

Inheritance

• Object
• DiagnosticableTree
• Widget
• RenderObjectWidget

Implementers

• ConstrainedLayoutBuilder
• LeafRenderObjectWidget
• ListWheelViewport
• MultiChildRenderObjectWidget
• RenderObjectToWidgetAdapter
• SingleChildRenderObjectWidget
• SliverWithKeepAliveWidget
• SlottedMultiChildRenderObjectWidget
• SlottedMultiChildRenderObjectWidgetMixin
• Table
• TwoDimensionalViewport

Constructors

RenderObjectWidget({Key? key})

Abstract const constructor. This constructor enables subclasses to provide const constructors so that they can be used in const expressions.

const

Properties

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()→ RenderObjectElement

RenderObjectWidgets always inflate to a RenderObjectElement subclass.

override

createRenderObject(BuildContext context)→ RenderObject

Creates an instance of the RenderObject class that thisRenderObjectWidget represents, using the configuration described by thisRenderObjectWidget.

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

didUnmountRenderObject(covariant RenderObject renderObject)→ void

A render object previously associated with this widget has been removed from the tree. The given RenderObject will be of the same type as returned by this object's createRenderObject.

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, int wrapWidth = 65})→ 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

updateRenderObject(BuildContext context, covariant RenderObject renderObject)→ void

Copies the configuration described by this RenderObjectWidget to the given RenderObject, which will be of the same type as returned by this object's createRenderObject.

Operators

operator ==(Object other)→ bool

The equality operator.

inherited