AlignTransition class Null safety

Animated version of an Align that animates its Align.alignment property.

Here's an illustration of the DecoratedBoxTransition widget, with it's DecoratedBoxTransition.decoration animated by a CurvedAnimation set to Curves.decelerate:

The following code implements the AlignTransition as seen in the video above:
To create a local project with this code sample, run:
flutter create --sample=widgets.AlignTransition.1 mysample

See also:

  • AnimatedAlign, which animates changes to the alignment without taking an explicit Animation argument.
  • PositionedTransition, a widget that animates its child from a start position to an end position over the lifetime of the animation.
  • RelativePositionedTransition, a widget that transitions its child's position based on the value of a rectangle relative to a bounding box.
  • SizeTransition, a widget that animates its own size and clips and aligns its child.
  • SlideTransition, a widget that animates the position of a widget relative to its normal position.


AlignTransition({Key? key, required Animation<AlignmentGeometry> alignment, required Widget child, double? widthFactor, double? heightFactor})
Creates an animated Align whose AlignmentGeometry animation updates the widget.


alignment Animation<AlignmentGeometry>
The animation that controls the child's alignment.
child Widget
The widget below this widget in the tree.
hashCode int
The hash code for this object.
@nonVirtual, read-only, inherited
heightFactor double?
If non-null, the child's height factor, see Align.heightFactor.
key Key?
Controls how one widget replaces another widget in the tree.
final, inherited
listenable Listenable
The Listenable to which this widget is listening.
final, inherited
runtimeType Type
A representation of the runtime type of the object.
read-only, inherited
widthFactor double?
If non-null, the child's width factor, see Align.widthFactor.


build(BuildContext context) Widget
Override this method to build widgets that depend on the state of the listenable (e.g., the current value of the animation).
createElement() StatefulElement
Creates a StatefulElement to manage this widget's location in the tree.
createState() State<AnimatedWidget>
Subclasses typically do not override this method.
debugDescribeChildren() List<DiagnosticsNode>
Returns a list of DiagnosticsNode objects describing this node's children.
@protected, inherited
debugFillProperties(DiagnosticPropertiesBuilder properties) → void
Add additional properties associated with the node.
noSuchMethod(Invocation invocation) → dynamic
Invoked when a non-existent method or property is accessed.
toDiagnosticsNode({String? name, DiagnosticsTreeStyle? style}) DiagnosticsNode
Returns a debug representation of the object that is used by debugging tools and by DiagnosticsNode.toStringDeep.
toString({DiagnosticLevel minLevel =}) String
A string representation of this object.
toStringDeep({String prefixLineOne = '', String? prefixOtherLines, DiagnosticLevel minLevel = DiagnosticLevel.debug}) String
Returns a string representation of this node and its descendants.
toStringShallow({String joiner = ', ', DiagnosticLevel minLevel = DiagnosticLevel.debug}) String
Returns a one-line detailed description of the object.
toStringShort() String
A short, textual description of this widget.


operator ==(Object other) bool
The equality operator.
@nonVirtual, inherited