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
-
- Object
- ChangeNotifier
- ValueNotifier
- 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