AnimatedSizeAndFade class

The AnimatedSizeAndFade widget does a fade and size transition between a "new" widget and an "old" widget/ previously set as a child. The "old" and the "new" children must have the same width, but can have different heights, and you don't need to know their sizes in advance. You can also define a duration and curve for both the fade and the size, separately.

Important: If the "new" child is the same widget type as the "old" child, but with different parameters, then AnimatedSizeAndFade will NOT do a transition between them, since as far as the framework is concerned, they are the same widget, and the existing widget can be updated with the new parameters. To force the transition to occur, set a Key (typically a ValueKey taking any widget data that would change the visual appearance of the widget) on each child widget that you wish to be considered unique.

Example:

 bool toggle=true;
 Widget widget1 = ...;
 Widget widget2 = ...;
 AnimatedSizeAndFade(
    child: toggle ? widget1 : widget2
 );

Show and Hide

The AnimatedSizeAndFade.showHide constructor may be used to show/hide a widget, by resizing it vertically while fading.

Example:

 bool toggle=true;
 Widget widget = ...;
 AnimatedSizeAndFade.showHide(
    show: toggle,
    child: widget,
 );

## How does AnimatedSizeAndFade compare to other similar widgets?

- With AnimatedCrossFade you must keep both the firstChild and secondChild, which is not
necessary with AnimatedSizeAndFade.

- With AnimatedSwitcher you may simply change its child, but then it only animates
the fade, not the size.

- AnimatedContainer also doesn't work unless you know the size of the children in advance.

Inheritance

Constructors

AnimatedSizeAndFade({Key? key, Widget? child, Duration fadeDuration = const Duration(milliseconds: 500), Duration sizeDuration = const Duration(milliseconds: 500), Curve fadeInCurve = Curves.easeInOut, Curve fadeOutCurve = Curves.easeInOut, Curve sizeCurve = Curves.easeInOut, Alignment alignment = Alignment.center})
AnimatedSizeAndFade.showHide({Key? key, Widget? child, required bool show, Duration fadeDuration = const Duration(milliseconds: 500), Duration sizeDuration = const Duration(milliseconds: 500), Curve fadeInCurve = Curves.easeInOut, Curve fadeOutCurve = Curves.easeInOut, Curve sizeCurve = Curves.easeInOut, Alignment alignment = Alignment.center}): Use this constructor when you want to show/hide the child, by doing a vertical size/fade. To that end, instead of changing the child, simply change show. Note this widget will try to have its width as big as possible, so put it in a parent with limited width constraints.

Properties

alignment → Alignment: final
child → Widget?: final
fadeDuration → Duration: final
fadeInCurve → Curve: final
fadeOutCurve → Curve: 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
show → bool: final
sizeCurve → Curve: final
sizeDuration → Duration: final

Methods

build(BuildContext context) → Widget: Describes the part of the user interface represented by this widget.
override
createElement() → StatelessElement: Creates a StatelessElement to manage this widget's location in the tree.
inherited
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}) → 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