ActionListenerModifier class

A helper widget for making sure that listeners on an action are removed properly.

Listeners on the Action class must have their listener callbacks removed with Action.removeActionListener when the listener is disposed of. This widget helps with that, by providing a lifetime for the connection between the listener and the Action, and by handling the adding and removing of the listener at the right points in the widget lifecycle.

If you listen to an Action widget in a widget hierarchy, you should use this widget. If you are using an Action outside of a widget context, then you must call removeListener yourself.

{@tool dartpad} This example shows how ActionListener handles adding and removing of the listener in the widget lifecycle.

** See code in examples/api/lib/widgets/actions/action_listener.0.dart ** {@end-tool}

Inheritance
Available extensions

Constructors

ActionListenerModifier({Key? key, Key? modifierKey, Widget? child, required ActionListenerCallback listener, required Action<Intent> action})
Create a const ActionListener.
const

Properties

action Action<Intent>
The Action that the callback will be registered with.
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 ActionListenerCallback
The ActionListenerCallback callback to register with the action.
final
modifierKey Key?
The actual key of the widget, which Modifier wrapped
finalinherited
runtimeType Type
A representation of the runtime type of the object.
no setterinherited

Methods

build(BuildContext context) Widget
Describes the part of the user interface represented by this widget.
inherited
buildWithChild(BuildContext context, Widget? child) Widget
A build method that receives an extra child parameter.
override
createElement() SingleChildStatelessElement
Create a SingleChildStatelessElement
inherited
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
modified() Modifier

Available on Widget, provided by the ModifierTransformer extension

Transform normal widget to Modifier
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, int wrapWidth = 65}) 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