ValueNotifier<T> class

A ChangeNotifier that holds a single value.

When value is replaced with something that is not equal to the old value as evaluated by the equality operator ==, this class notifies its listeners.

Limitations

Because this class only notifies listeners when the value's identity changes, listeners will not be notified when mutable state within the value itself changes.

For example, a ValueNotifier<List<int>> will not notify its listeners when the contents of the list are changed.

As a result, this class is best used with only immutable data types.

For mutable data types, consider extending ChangeNotifier directly.

Inheritance
Implemented types
Implementers

Constructors

ValueNotifier(T _value)
Creates a ChangeNotifier that wraps this value.

Properties

hashCode int
The hash code for this object.
no setterinherited
hasListeners bool
Whether any listeners are currently registered.
no setterinherited
runtimeType Type
A representation of the runtime type of the object.
no setterinherited
value ↔ T
The current value stored in this notifier.
getter/setter pairoverride-getter

Methods

addListener(VoidCallback listener) → void
Register a closure to be called when the object changes.
inherited
dispose() → void
Discards any resources used by the object. After this is called, the object is not in a usable state and should be discarded (calls to addListener will throw after the object is disposed).
inherited
noSuchMethod(Invocation invocation) → dynamic
Invoked when a nonexistent method or property is accessed.
inherited
notifyListeners() → void
Call all the registered listeners.
inherited
removeListener(VoidCallback listener) → void
Remove a previously registered closure from the list of closures that are notified when the object changes.
inherited
toString() String
A string representation of this object.
override

Operators

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