ViewStateListener<T, C extends Cubit<ViewState>> class

ViewStateListener is responsible for performing an action based on the ViewState. It should be used for functionality that needs to occur only in response to a state change such as navigation, showing a SnackBar, showing a Dialog, etc. ViewStateListener is a wrapper over the BlocListener widget so it accepts a bloc object as well as a child widget and a set of handy callbacks corresponding to a given state: onLoading callback for the data loading state, onRefreshing callback for the data refreshing state, onSuccess callback for the data success state, onEmpty callback for for no result state, onError callback function for an error state.

T - the type of elements, C - the type of cubit.



ViewStateListener({Key key, C cubit, ViewStateListenerCondition listenWhen, LoadingCallback onLoading, RefreshingCallback<T> onRefreshing, SuccessCallback<T> onSuccess, EmptyCallback onEmpty, ErrorCallback onError, Widget child})


child Widget
The widget which will be rendered as a descendant of the BlocListenerBase.
final, inherited
cubit → C
The cubit whose state will be listened to. Whenever the cubit's state changes, listener will be invoked.
final, inherited
hashCode int
The hash code for this object. [...]
@nonVirtual, read-only, inherited
key Key
Controls how one widget replaces another widget in the tree. [...]
final, inherited
listener BlocWidgetListener<ViewState>
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, inherited
listenWhen BlocListenerCondition<ViewState>
An optional listenWhen can be implemented for more granular control over when listener is called. listenWhen will be invoked on each cubit 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 cubit when the BlocListener is initialized. listenWhen is optional and if omitted, it will default to true. [...]
final, inherited
runtimeType Type
A representation of the runtime type of the object.
read-only, inherited


createElement() SingleChildStatefulElement
Creates a StatefulElement to manage this widget's location in the tree. [...]
createState() SingleChildState<BlocListenerBase<C, ViewState>>
Creates the mutable state for this widget at a given location in the tree. [...]
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. [...]
noSuchMethod(Invocation invocation) → dynamic
Invoked when a non-existent method or property is accessed. [...]
toDiagnosticsNode({String name, DiagnosticsTreeStyle style}) DiagnosticsNode
Returns a debug representation of the object that is used by debugging tools and by DiagnosticsNode.toStringDeep. [...]
toString({DiagnosticLevel minLevel =}) String
A string representation of this object. [...]
toStringDeep({String prefixLineOne = '', String prefixOtherLines, DiagnosticLevel minLevel = DiagnosticLevel.debug}) String
Returns a string representation of this node and its descendants. [...]
toStringShallow({String joiner = ', ', DiagnosticLevel minLevel = DiagnosticLevel.debug}) String
Returns a one-line detailed description of the object. [...]
toStringShort() String
A short, textual description of this widget.


operator ==(Object other) bool
The equality operator. [...]
@nonVirtual, inherited