SliverAnimatedOpacity class

Animated version of SliverOpacity which automatically transitions the sliver child's opacity over a given duration whenever the given opacity changes.

Animating an opacity is relatively expensive because it requires painting the sliver child into an intermediate buffer.

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

Creates a CustomScrollView with a SliverFixedExtentList and a FloatingActionButton. Pressing the button animates the lists' opacity.
To create a local project with this code sample, run:
flutter create --sample=widgets.SliverAnimatedOpacity.1 mysample

See also:

  • SliverFadeTransition, an explicitly animated version of this widget, where an Animation is provided by the caller instead of being built in.
  • AnimatedOpacity, for automatically transitioning a box child's opacity over a given duration whenever the given opacity changes.
Inheritance

Constructors

SliverAnimatedOpacity({Key key, Widget sliver, @required double opacity, Curve curve: Curves.linear, @required Duration duration, VoidCallback onEnd, bool alwaysIncludeSemantics: false})
Creates a widget that animates its opacity implicitly. [...]
const

Properties

alwaysIncludeSemantics bool
Whether the semantic information of the children is always included. [...]
final
opacity double
The target opacity. [...]
final
sliver Widget
The sliver below this widget in the tree.
final
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
hashCode int
The hash code for this object. [...]
@nonVirtual, read-only, inherited
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

Methods

createState() → _SliverAnimatedOpacityState
Creates the mutable state for this widget at a given location in the tree. [...]
override
debugFillProperties(DiagnosticPropertiesBuilder properties) → void
Add additional properties associated with the node. [...]
override
createElement() StatefulElement
Creates a StatefulElement to manage this widget's location in the tree. [...]
inherited
debugDescribeChildren() List<DiagnosticsNode>
Returns a list of DiagnosticsNode objects describing this node's children.
@protected, inherited
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
Returns 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, inherited