SlottedMultiChildRenderObjectWidget<SlotType, ChildType extends RenderObject> class abstract

A superclass for RenderObjectWidgets that configure RenderObject subclasses that organize their children in different slots.

Implementers of this mixin have to provide the list of available slots by overriding slots. The list of slots must never change for a given class implementing this mixin. In the common case, Enum values are used as slots and slots is typically implemented to return the value of the enum's values getter.

Furthermore, childForSlot must be implemented to return the current widget configuration for a given slot.

The RenderObject returned by createRenderObject and updated by updateRenderObject must implement SlottedContainerRenderObjectMixin.

The type parameter SlotType is the type for the slots to be used by this RenderObjectWidget and the RenderObject it configures. In the typical case, SlotType is an Enum type.

The type parameter ChildType is the type used for the RenderObject children (e.g. RenderBox or RenderSliver). In the typical case, ChildType is RenderBox. This class does not support having different kinds of children for different slots.

This example uses the SlottedMultiChildRenderObjectWidget in combination with the SlottedContainerRenderObjectMixin to implement a widget that provides two slots: topLeft and bottomRight. The widget arranges the children in those slots diagonally.

To create a local project with this code sample, run:
flutter create --sample=widgets.SlottedMultiChildRenderObjectWidget.1 mysample

See also:

Mixed in types


SlottedMultiChildRenderObjectWidget({Key? key})
Abstract const constructor. This constructor enables subclasses to provide const constructors so that they can be used in const expressions.


hashCode int
The hash code for this object.
no setterinherited
key Key?
Controls how one widget replaces another widget in the tree.
runtimeType Type
A representation of the runtime type of the object.
no setterinherited
slots Iterable<SlotType>
Returns a list of all available slots.
no setterinherited


childForSlot(SlotType slot) Widget?
Returns the widget that is currently occupying the provided slot.
createElement() SlottedRenderObjectElement<SlotType, ChildType>
RenderObjectWidgets always inflate to a RenderObjectElement subclass.
createRenderObject(BuildContext context) SlottedContainerRenderObjectMixin<SlotType, ChildType>
Creates an instance of the RenderObject class that this RenderObjectWidget represents, using the configuration described by this RenderObjectWidget.
debugDescribeChildren() List<DiagnosticsNode>
Returns a list of DiagnosticsNode objects describing this node's children.
debugFillProperties(DiagnosticPropertiesBuilder properties) → void
Add additional properties associated with the node.
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.
toDiagnosticsNode({String? name, DiagnosticsTreeStyle? style}) DiagnosticsNode
Returns a debug representation of the object that is used by debugging tools and by DiagnosticsNode.toStringDeep.
toString({DiagnosticLevel minLevel =}) String
A string representation of this object.
toStringDeep({String prefixLineOne = '', String? prefixOtherLines, DiagnosticLevel minLevel = DiagnosticLevel.debug}) String
Returns a string representation of this node and its descendants.
toStringShallow({String joiner = ', ', DiagnosticLevel minLevel = DiagnosticLevel.debug}) String
Returns a one-line detailed description of the object.
toStringShort() String
A short, textual description of this widget.
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.


operator ==(Object other) bool
The equality operator.