AnimatedPositionedDirectional class Null safety

Animated version of PositionedDirectional which automatically transitions the child's position over a given duration whenever the given position changes.

The ambient Directionality is used to determine whether start is to the left or to the right.

Only works if it's the child of a Stack.

This widget is a good choice if the size of the child would end up changing as a result of this animation. If the size is intended to remain the same, with only the position changing over time, then consider SlideTransition instead. SlideTransition only triggers a repaint each frame of the animation, whereas AnimatedPositionedDirectional will trigger a relayout as well. (SlideTransition is also text-direction-aware.)

Here's an illustration of what using this widget looks like, using a curve of Curves.fastOutSlowIn.

See also:



AnimatedPositionedDirectional({Key? key, required Widget child, double? start, double? top, double? end, double? bottom, double? width, double? height, Curve curve = Curves.linear, required Duration duration, VoidCallback? onEnd})
Creates a widget that animates its position implicitly.


bottom double?
The offset of the child's bottom edge from the bottom of the stack.
child Widget
The widget below this widget in the tree.
curve Curve
The curve to apply when animating the parameters of this container.
final, inherited
duration Duration
The duration over which to animate the parameters of this container.
final, inherited
end double?
The offset of the child's end edge from the end of the stack.
hashCode int
The hash code for this object.
@nonVirtual, read-only, inherited
height double?
The child's height.
key Key?
Controls how one widget replaces another widget in the tree.
final, inherited
onEnd VoidCallback?
Called every time an animation completes.
final, inherited
runtimeType Type
A representation of the runtime type of the object.
read-only, inherited
start double?
The offset of the child's start edge from the start of the stack.
top double?
The offset of the child's top edge from the top of the stack.
width double?
The child's width.


createElement() StatefulElement
Creates a StatefulElement to manage this widget's location in the tree.
createState() AnimatedWidgetBaseState<AnimatedPositionedDirectional>
Creates the mutable state for this widget at a given location in the tree.
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