Sequence class

Shows one widget at a time from an ordered sequence.

Use a SequenceController to move to the next or previous child, or to select a child by index. Without a transition builder, navigation changes the visible child immediately.

A directional transition wraps both participating children. Its animation runs from 0 (hidden) to 1 (visible), so the destination runs forward while the source runs in reverse. Paint and compositing transitions such as fades, slides, and scales generally impose less work than transitions that lay out their child on every animation frame.

final controller = SequenceController();

Sequence(
  controller: controller,
  nextTransition: (child, animation) => FadeTransition(
    opacity: animation,
    child: child,
  ),
  children: const [
    Text('First'),
    Text('Second'),
  ],
)

See the Sequence guide for navigation, transitions, and child lifecycle behavior.

Inheritance

Constructors

Sequence({required List<Widget> children, SequenceTransitionBuilder? nextTransition, SequenceTransitionBuilder? previousTransition, SequenceController? controller, Duration duration = const Duration(milliseconds: 300), Duration reverseDuration = const Duration(milliseconds: 300), bool keepMounted = false, AlignmentGeometry alignment = AlignmentDirectional.topStart, Key? key})
Creates a widget that displays one child from children at a time.
const

Properties

alignment → AlignmentGeometry
How differently sized children are aligned during a transition.
final
children → List<Widget>
Widgets displayed by the sequence.
final
controller → SequenceController?
Controller used to navigate and observe the selected children index.
final
duration → Duration
Duration used to animate the destination from hidden to visible.
final
hashCode → int
The hash code for this object.
no setterinherited
keepMounted → bool
Whether inactive children remain mounted.
final
key → Key?
Controls how one widget replaces another widget in the tree.
finalinherited
nextTransition → SequenceTransitionBuilder?
Transition used when navigating to a higher index.
final
previousTransition → SequenceTransitionBuilder?
Transition used when navigating to a lower index.
final
reverseDuration → Duration
Duration used to animate the source from visible to hidden.
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<Sequence>
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, 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