ValueListenable<T> class

An interface for subclasses of Listenable that expose a value.

This interface is implemented by ValueNotifier<T> and Animation<T>, and allows other APIs to accept either of those implementations interchangeably.

Inheritance

Implementers

Constructors

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

value → T: The current value of the object. When the value changes, the callbacks registered with addListener will be invoked.
read-only
hashCode → int: The hash code for this object. [...]
read-only, inherited
runtimeType → Type: A representation of the runtime type of the object.
read-only, inherited

addListener(VoidCallback listener) → void: Register a closure to be called when the object notifies its listeners.
inherited
noSuchMethod(Invocation invocation) → dynamic: Invoked when a non-existent method or property is accessed. [...]
inherited
removeListener(VoidCallback listener) → void: Remove a previously registered closure from the list of closures that the object notifies.
inherited
toString() → String: Returns a string representation of this object.
inherited