AnimatedPositioned class Null safety
Animated version of Positioned which automatically transitions the child's position over a given duration whenever the given position changes.
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 AnimatedPositioned will trigger a relayout as well.
Here's an illustration of what using this widget looks like, using a curve of Curves.fastOutSlowIn.
For the animation, you can choose a curve as well as a duration and the widget will automatically animate to the new target position. If you require more control over the animation (e.g. if you want to stop it mid-animation), consider using a PositionedTransition instead, which takes a provided Animation as an argument. While that allows you to fine-tune the animation, it also requires more development overhead as you have to manually manage the lifecycle of the underlying AnimationController.
height
, width
, and
Positioned properties when tapped.
flutter create --sample=widgets.AnimatedPositioned.1 mysample
See also:
- AnimatedPositionedDirectional, which adapts to the ambient Directionality (the same as this widget, but for animating PositionedDirectional).
- Inheritance
-
- Object
- DiagnosticableTree
- Widget
- StatefulWidget
- ImplicitlyAnimatedWidget
- AnimatedPositioned
Constructors
- AnimatedPositioned({Key? key, required Widget child, double? left, double? top, double? right, double? bottom, double? width, double? height, Curve curve = Curves.linear, required Duration duration, VoidCallback? onEnd})
-
Creates a widget that animates its position implicitly.
const
- AnimatedPositioned.fromRect({Key? key, required Widget child, required Rect rect, Curve curve = Curves.linear, required Duration duration, VoidCallback? onEnd})
- Creates a widget that animates the rectangle it occupies implicitly.
Properties
- bottom → double?
-
The offset of the child's bottom edge from the bottom of the stack.
final
- child → Widget
-
The widget below this widget in the tree.
final
- curve → Curve
-
The curve to apply when animating the parameters of this container.
finalinherited
- duration → Duration
-
The duration over which to animate the parameters of this container.
finalinherited
- hashCode → int
- The hash code for this object.
- height → double?
-
The child's height.
final
- key → Key?
-
Controls how one widget replaces another widget in the tree.
finalinherited
- left → double?
-
The offset of the child's left edge from the left of the stack.
final
- onEnd → VoidCallback?
-
Called every time an animation completes.
finalinherited
- right → double?
-
The offset of the child's right edge from the right of the stack.
final
- runtimeType → Type
-
A representation of the runtime type of the object.
read-onlyinherited
- top → double?
-
The offset of the child's top edge from the top of the stack.
final
- width → double?
-
The child's width.
final
Methods
-
createElement(
) → StatefulElement -
Creates a StatefulElement to manage this widget's location in the tree.
inherited
-
createState(
) → AnimatedWidgetBaseState< AnimatedPositioned> -
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.protected">@protectedinherited -
debugFillProperties(
DiagnosticPropertiesBuilder properties) → void -
Add additional properties associated with the node.
override
-
noSuchMethod(
Invocation invocation) → dynamic -
Invoked when a non-existent 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}) → 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.
nonVirtual">@nonVirtualinherited