Key class - foundation library (original) (raw)

A Key is an identifier for Widgets, Elements and SemanticsNodes.

A new widget will only be used to update an existing element if its key is the same as the key of the current widget associated with the element.

Keys must be unique amongst the Elements with the same parent.

Subclasses of Key should either subclass LocalKey or GlobalKey.

See also:

• Widget.key, which discusses how widgets use keys.

Implementers

• GlobalKey
• LocalKey

Annotations

• @immutable

Constructors

Key(String value)

Construct a ValueKey with the given String.

const

factory

Key.empty()

Default constructor, used by subclasses.

const

Properties

hashCode → int

The hash code for this object.

no setterinherited

runtimeType → Type

A representation of the runtime type of the object.

no setterinherited

Methods

noSuchMethod(Invocation invocation)→ dynamic

Invoked when a nonexistent method or property is accessed.

inherited

toString()→ String

A string representation of this object.

inherited

Operators

operator ==(Object other)→ bool

The equality operator.

inherited