FocusTraversalOrder class Null safety

An inherited widget that describes the order in which its child subtree should be traversed.

Only orders of the same type are comparable. If a set of widgets in the same FocusTraversalGroup contains orders that are not comparable with each other, it will assert, since the ordering between such keys is undefined. To avoid collisions, use a FocusTraversalGroup to group similarly ordered widgets together.

When overriding, FocusOrder.doCompare must be overridden instead of FocusOrder.compareTo, which calls FocusOrder.doCompare to do the actual comparison.

The order for a widget is determined by the FocusOrder returned by FocusTraversalOrder.of for a particular context.

Inheritance

Constructors

FocusTraversalOrder({Key? key, required FocusOrder order, required Widget child})
Creates an inherited widget used to describe the focus order of the child subtree.
const

Properties

child → Widget
The widget below this widget in the tree.
finalinherited
hashCode → int
The hash code for this object.
nonVirtual">@nonVirtualread-onlyinherited
key → Key?
Controls how one widget replaces another widget in the tree.
finalinherited
order → FocusOrder
The order for the widget descendants of this FocusTraversalOrder.
final
runtimeType → Type
A representation of the runtime type of the object.
read-onlyinherited

Methods

createElement() → InheritedElement
Inflates this configuration to a concrete instance.
inherited
debugDescribeChildren() → List<DiagnosticsNode>
Returns a list of DiagnosticsNode objects describing this node's children.
protected">@protectedinherited
debugFillProperties(DiagnosticPropertiesBuilder properties) → void
Add additional properties associated with the node.
override
noSuchMethod(Invocation invocation) → dynamic
Invoked when a non-existent 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
updateShouldNotify(covariant InheritedWidget oldWidget) → bool
Whether the framework should notify widgets that inherit from this widget.
override

Operators

operator ==(Object other) → bool
The equality operator.
nonVirtual">@nonVirtualinherited

Static Methods

maybeOf(BuildContext context) → FocusOrder?
Finds the FocusOrder in the nearest ancestor FocusTraversalOrder widget.
of(BuildContext context) → FocusOrder
Finds the FocusOrder in the nearest ancestor FocusTraversalOrder widget.