Morph class

Animates a widget between two matching locations.

Give each appearance a stable MorphTarget with the same tag. Mounting a new appearance moves the shared visual to it; removing it returns to the most recently mounted appearance that remains. Rebuilds do not reorder appearances. A covered appearance cannot start a child-replacement flight.

Register a stable MorphNavigatorObserver from the creation of each Navigator containing Morphs. Local transitions also work in a standalone Overlay. Without an Overlay, child renders normally without transitions.

Eligible Widgets receive specialized transitions automatically. Other combinations move between their endpoint geometry and switch content halfway through. Configure flightConfig to change child replacement or supply a custom transition.

Generic transitions preserve inherited themes and MediaQuery values. They do not preserve other inherited values introduced locally around an endpoint. A live in-flight subtree must not contain GlobalKeys that are also mounted at an endpoint. Use MorphDescendant with MorphDescendantFlightBehavior.snapshot or MorphDescendantFlightBehavior.hide to keep such a subtree at its resting endpoint, or use a custom delegate when it must have a different in-flight visual.

When animateChildChanges is true, replacing child on the same Morph starts an in-place transition. Give the old and new children the same non-null key when a rebuild should update the resting widget without animating. Replacing an unkeyed child starts a transition whenever its widget instance changes.

When animations are disabled before a transition starts, Morph shows the destination immediately without invoking lifecycle callbacks. If they become disabled during a transition, Morph finishes immediately without invoking onReceived or onEnd; an earlier onStart remains invoked.

See the Morph guide for endpoint setup, automatic transitions, and customization.

Inheritance

• Object
• DiagnosticableTree
• Widget
• StatefulWidget
• Morph

Constructors

Morph({required MorphTarget target, required Widget child, MorphFlightConfig flightConfig = const MorphFlightConfig.auto(), Duration? duration, Curve? curve, bool watchDestination = false, bool animateChildChanges = false, VoidCallback? onStart, VoidCallback? onEnd, VoidCallback? onReceived, Key? key})

Creates an appearance that can transition to another with an equal tag.

const

Properties

animateChildChanges → bool

Whether replacing child can start an in-place transition.

final

child → Widget

Widget shown at this location when no transition is running.

final

curve → Curve?

Curve applied while moving from the source to the destination.

final

duration → Duration?

Duration of transitions started by this Morph.

final

flightConfig → MorphFlightConfig

How the shared element appears during its transition.

final

hashCode → int

The hash code for this object.

no setter, inherited

key → Key?

Controls how one widget replaces another widget in the tree.

final, inherited

onEnd → VoidCallback?

Called on the source after the transition reaches the destination.

final

onReceived → VoidCallback?

Called on the destination immediately before the source's onEnd.

final

onStart → VoidCallback?

Called on the source when its transition starts.

final

runtimeType → Type

A representation of the runtime type of the object.

no setter, inherited

target → MorphTarget

Identifier shared by the source, destination and sibling widgets.

final

watchDestination → bool

Whether a flight departing from this Morph follows changes to its destination's geometry and snapshotted descendants.

final

Methods

createElement() → StatefulElement

Creates a StatefulElement to manage this widget's location in the tree.

inherited

createState() → State<Morph>

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