BackButtonListener class

A convenience widget that registers a callback for when the back button is pressed.

In order to use this widget, there must be an ancestor Router widget in the tree that has a RootBackButtonDispatcher. e.g. The Router widget created by the MaterialApp.router has a built-in RootBackButtonDispatcher by default.

It only applies to platforms that accept back button clicks, such as Android.

It can be useful for scenarios, in which you create a different state in your screen but don't want to use a new page for that.

Inheritance

Constructors

BackButtonListener({Key? key, required Widget child, required ValueGetter<Future<bool>> onBackButtonPressed})
Creates a BackButtonListener widget .
const

Properties

child Widget
The widget below this widget in the tree.
final
hashCode int
The hash code for this object.
no setterinherited
key Key?
Controls how one widget replaces another widget in the tree.
finalinherited
onBackButtonPressed ValueGetter<Future<bool>>
The callback function that will be called when the back button is pressed.
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<BackButtonListener>
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