UniqueWidget<T extends State<StatefulWidget>> class Null safety

Base class for stateful widgets that have exactly one inflated instance in the tree.

Such widgets must be given a GlobalKey. This key can be generated by the subclass from its Type object, e.g. by calling super(key: new GlobalObjectKey(MyWidget)) where MyWidget is the name of the subclass.

Since only one instance can be inflated at a time, there is only ever one corresponding State object. That object is exposed, for convenience, via the currentState property.

When subclassing UniqueWidget, provide the corresponding State subclass as the type argument.

Inheritance

Constructors

UniqueWidget({required GlobalKey<T> key})
Creates a widget that has exactly one inflated instance in the tree.
const

Properties

currentState → T?
The state for the unique inflated instance of this widget.
read-only
hashCode → int
The hash code for this object.
nonVirtual">@nonVirtualread-onlyinherited
key → Key?
Controls how one widget replaces another widget in the tree.
finalinherited
runtimeType → Type
A representation of the runtime type of the object.
read-onlyinherited

Methods

createElement() → StatefulElement
Creates a StatefulElement to manage this widget's location in the tree.
inherited
createState() → T
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.
protected">@protectedinherited
debugFillProperties(DiagnosticPropertiesBuilder properties) → void
Add additional properties associated with the node.
inherited
noSuchMethod(Invocation invocation) → dynamic
Invoked when a non-existent 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.
nonVirtual">@nonVirtualinherited