NibLayoutGroup class

Animates children to their new positions whenever a rebuild changes their layout, using the FLIP (First, Last, Invert, Play) technique.

Each widget in children must carry a non-null, unique Key, which identifies it across rebuilds so NibLayoutGroup can measure how far it moved:

  • First: before the new layout is applied, the current position of every child present in both the old and new children is recorded.
  • Last: after the new layout is applied (via WidgetsBinding.addPostFrameCallback), each tracked child's new position is compared against its recorded one.
  • Invert: if a child moved, its NibMotion is immediately offset (no animation) so it visually stays at its old position.
  • Play: that offset is animated back to zero with transition, so the child appears to travel smoothly from its old position to its new one.

A child whose key is newly added to children mounts without a FLIP animation. A child whose key is removed from children stops being tracked; re-adding it later is treated as a new child.

Inheritance
Available extensions

Constructors

NibLayoutGroup({Key? key, required List<Widget> children, NibTransition? transition})
Creates a NibLayoutGroup.
const

Properties

children → List<Widget>
The widgets to lay out and track. Each must carry a non-null, unique Key.
final
hashCode → int
The hash code for this object.
no setterinherited
key → Key?
Controls how one widget replaces another widget in the tree.
finalinherited
runtimeType → Type
A representation of the runtime type of the object.
no setterinherited
transition → NibTransition?
The transition used to animate a moved child back to its new position.
final

Methods

animate({Object? initial, Object? animate, NibAnim? exit, NibTransition? transition, NibAnim? whileTap, NibAnim? whileHover, Key? key}) → Widget

Available on Widget, provided by the NibMotionWidgetExtension extension

Wraps this widget in a NibMotion.
createElement() → StatefulElement
Creates a StatefulElement to manage this widget's location in the tree.
inherited
createState() → State<NibLayoutGroup>
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
revealOnScroll({NibAnim? initial, bool once = true}) → Widget

Available on Widget, provided by the NibMotionWidgetExtension extension

Wraps this widget in a NibScrollReveal.
shimmer({bool enabled = true}) → Widget

Available on Widget, provided by the NibMotionWidgetExtension extension

Wraps this widget in a NibShimmer.
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