RequestFocusAction class Null safety

An Action that requests the focus on the node it is given in its RequestFocusIntent.

This action can be used to request focus for a particular node, by calling Action.invoke like so:

Actions.invoke(context, const RequestFocusIntent(focusNode));

Where the focusNode is the node for which the focus will be requested.

The difference between requesting focus in this way versus calling FocusNode.requestFocus directly is that it will use the Action registered in the nearest Actions widget associated with RequestFocusIntent to make the request, rather than just requesting focus directly. This allows the action to have additional side effects, like logging, or undo and redo functionality.

This RequestFocusAction class is the default action associated with the RequestFocusIntent in the WidgetsApp, and it simply requests focus. You can redefine the associated action with your own Actions widget.

See FocusTraversalPolicy for more information about focus traversal.

Inheritance

Constructors

RequestFocusAction()

Properties

callingAction Action<RequestFocusIntent>?
The Action overridden by this Action.
@protected, read-only, inherited
hashCode int
The hash code for this object.
read-only, inherited
intentType Type
Gets the type of intent this action responds to.
read-only, inherited
isActionEnabled bool
Whether this Action is inherently enabled.
read-only, inherited
runtimeType Type
A representation of the runtime type of the object.
read-only, inherited

Methods

addActionListener(ActionListenerCallback listener) → void
Register a callback to listen for changes to the state of this action.
@mustCallSuper, inherited
consumesKey(RequestFocusIntent intent) bool
Indicates whether this action should treat key events mapped to this action as being "handled" when it is invoked via the key event.
inherited
debugFillProperties(DiagnosticPropertiesBuilder properties) → void
Add additional properties associated with the node.
@mustCallSuper, @protected, inherited
invoke(RequestFocusIntent intent) → void
Called when the action is to be performed.
override
isEnabled(RequestFocusIntent intent) bool
Returns true if the action is enabled and is ready to be invoked.
inherited
noSuchMethod(Invocation invocation) → dynamic
Invoked when a non-existent method or property is accessed.
inherited
notifyActionListeners() → void
Call all the registered listeners.
removeActionListener(ActionListenerCallback listener) → void
Remove a previously registered closure from the list of closures that are notified when the object changes.
@mustCallSuper, 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
toStringShort() String
A brief description of this object, usually just the runtimeType and the hashCode.
inherited

Operators

operator ==(Object other) bool
The equality operator.
inherited