PausableValueNotifier<T> class
A ValueNotifier, which allows clients to pause new value notifications.
When paused, the value property returns whatever the value was when this PausableValueNotifier was paused, regardless of the latest values that was set on this PausableValueNotifier.
Pausing notifications is useful when a series of changes might occur in rapid succession, and only the final value is relevant to listeners.
For example, consider a user's selection in an editor. A single user interaction might result in any number of commands and reactions executing, which might alter the user's selection multiple times within a single frame of execution. None of these intermediate selection values are relevant to the rest of the editor. In fact, if the rest of the editor was notified of these transient selection values, then the rest of the editor might do things that it shouldn't do, and cause the editor to enter an inconsistent state.
Instead, a PausableValueNotifier lets the editor pipeline disable notifications as it runs the pipeline, and then re-enable notifications when all commands and reactions are done executing.
- Inheritance
-
- Object
- ChangeNotifier
- ValueNotifier<
T> - PausableValueNotifier
Constructors
- PausableValueNotifier(T 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
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
-
pauseNotifications(
) → void -
removeListener(
VoidCallback listener) → void -
Remove a previously registered closure from the list of closures that are
notified when the object changes.
inherited
-
resumeNotifications(
) → void -
toString(
) → String -
A string representation of this object.
inherited
Operators
-
operator ==(
Object other) → bool -
The equality operator.
inherited