InheritedNotifier<
An inherited widget for a Listenable notifier, which updates its dependencies when the notifier is triggered.
This is a variant of InheritedWidget, specialised for subclasses of Listenable, such as ChangeNotifier or ValueNotifier.
Dependents are notified whenever the notifier sends notifications, or whenever the identity of the notifier changes.
Multiple notifications are coalesced, so that dependents only rebuild once even if the notifier fires multiple times between two frames.
Typically this class is subclassed with a class that provides an of static
method that calls BuildContext.inheritFromWidgetOfExactType with that
class.
The updateShouldNotify method may also be overridden, to change the logic in the cases where notifier itself is changed. The updateShouldNotify method is called with the old notifier in the case of the notifier being changed. When it returns true, the dependents are marked as needing to be rebuilt this frame.
See also:
- Animation, an implementation of Listenable that ticks each frame to update a value.
- ViewportOffset or its subclass ScrollPosition, implementations of Listenable that trigger when a view is scrolled.
- InheritedWidget, an inherited widget that only notifies dependents when its value is different.
- InheritedModel, an inherited widget that allows clients to subscribe to changes for subparts of the value.
- Inheritance
- Object
- Diagnosticable
- DiagnosticableTree
- Widget
- ProxyWidget
- InheritedWidget
- InheritedNotifier
Constructors
- InheritedNotifier({Key key, T notifier, @required Widget child })
-
Create an inherited widget that updates its dependents when
notifiersends notifications. [...]const
Properties
- notifier → T
-
The Listenable object to which to listen. [...]
final
- child → Widget
-
The widget below this widget in the tree. [...]
final, inherited
- hashCode → int
-
The hash code for this object. [...]
read-only, inherited
- key → Key
-
Controls how one widget replaces another widget in the tree. [...]
final, inherited
- runtimeType → Type
-
A representation of the runtime type of the object.
read-only, inherited
Methods
-
createElement(
) → _InheritedNotifierElement< T> -
Inflates this configuration to a concrete instance. [...]
override
-
updateShouldNotify(
covariant InheritedNotifier< T> oldWidget) → bool -
Whether the framework should notify widgets that inherit from this widget. [...]
override
-
debugDescribeChildren(
) → List< DiagnosticsNode> -
Returns a list of DiagnosticsNode objects describing this node's
children. [...]
@protected, inherited
-
debugFillProperties(
DiagnosticPropertiesBuilder properties) → void -
Add additional properties associated with the node. [...]
inherited
-
noSuchMethod(
Invocation invocation) → dynamic -
Invoked when a non-existent method or property is accessed. [...]
inherited
-
toDiagnosticsNode(
{String name, DiagnosticsTreeStyle style }) → DiagnosticsNode -
Returns a debug representation of the object that is used by debugging
tools and by toStringDeep. [...]
inherited
-
toString(
{DiagnosticLevel minLevel: DiagnosticLevel.debug }) → String -
Returns a string representation of this object.
inherited
-
toStringDeep(
{String prefixLineOne: '', String prefixOtherLines, DiagnosticLevel minLevel: DiagnosticLevel.debug }) → String -
Returns a string representation of this node and its descendants. [...]
inherited
-
toStringShallow(
{String joiner: ', ', DiagnosticLevel minLevel: DiagnosticLevel.debug }) → String -
Returns a one-line detailed description of the object. [...]
inherited
-
toStringShort(
) → String -
A short, textual description of this widget.
inherited
Operators
-
operator ==(
dynamic other) → bool -
The equality operator. [...]
inherited