BlocListenerBase<B extends IStateObservable<S>, S> class abstract

Base class for widgets that listen to state changes in a specified bloc.

A BlocListenerBase is stateful and maintains the state subscription. The type of the state and what happens with each state change is defined by sub-classes.

Inheritance
Implementers

Constructors

BlocListenerBase({required BlocWidgetListener<S> listener, B? bloc, Widget? child, BlocListenerCondition<S>? listenWhen, Key? key})
Base class for widgets that listen to state changes in a specified bloc.
const

Properties

bloc → B?
The bloc whose state will be listened to. Whenever the bloc's state changes, listener will be invoked.
final
child Widget?
The widget which will be rendered as a descendant of the BlocListenerBase.
final
hashCode int
The hash code for this object.
no setterinherited
key Key?
Controls how one widget replaces another widget in the tree.
finalinherited
listener BlocWidgetListener<S>
The BlocWidgetListener which will be called on every state change. This listener should be used for any code which needs to execute in response to a state change.
final
listenWhen BlocListenerCondition<S>?
An optional listenWhen can be implemented for more granular control over when listener is called. listenWhen will be invoked on each bloc state change. listenWhen takes the previous state and current state and must return a bool which determines whether or not the listener function will be invoked. The previous state will be initialized to the state of the bloc when the BlocListener is initialized. listenWhen is optional and if omitted, it will default to true.
final
runtimeType Type
A representation of the runtime type of the object.
no setterinherited

Methods

createElement() StatefulElement
Creates a StatefulElement to manage this widget's location in the tree.
inherited
createState() State<BlocListenerBase<B, S>>
Creates the mutable state for this widget at a given location in the tree.
override
debugDescribeChildren() List<DiagnosticsNode>
Returns a list of DiagnosticsNode objects describing this node's children.
inherited
debugFillProperties(DiagnosticPropertiesBuilder properties) → void
Add additional properties associated with the node.
inherited
noSuchMethod(Invocation invocation) → dynamic
Invoked when a nonexistent 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 DiagnosticsNode.toStringDeep.
inherited
toString({DiagnosticLevel minLevel = DiagnosticLevel.info}) String
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 ==(Object other) bool
The equality operator.
inherited