ParallaxImage class

An image that shifts vertically as it moves through an ancestor scrollable, creating a parallax effect for list items.

Place it directly inside any scrollable (a ListView, a SingleChildScrollView, ...). It listens to the enclosing scrollable's position and repaints only the image transform via a Flow delegate; there is no internal scrollable and no setState per frame.

ListView(
  children: [
    for (final location in locations)
      ParallaxImage(
        imageProvider: AssetImage(location.asset),
        height: 220,
      ),
  ],
)

Under reduced motion (or with parallaxFactor 0, or outside any scrollable) the image renders statically.

Inheritance

Constructors

ParallaxImage({Key? key, required ImageProvider<Object> imageProvider, double parallaxFactor = 0.3, double height = 200.0, BoxFit fit = BoxFit.cover, String? semanticLabel})
Creates a parallax image.
const

Properties

fit → BoxFit
How the image covers its area. Defaults to BoxFit.cover.
final
hashCode → int
The hash code for this object.
no setterinherited
height → double
The height of the clipped image area. Defaults to 200.0.
final
imageProvider → ImageProvider<Object>
The image to display.
final
key → Key?
Controls how one widget replaces another widget in the tree.
finalinherited
parallaxFactor → double
How strongly the image shifts as the item crosses the viewport.
final
runtimeType → Type
A representation of the runtime type of the object.
no setterinherited
semanticLabel → String?
Semantic description of the image. When null the image is decorative.
final

Methods

createElement() → StatefulElement
Creates a StatefulElement to manage this widget's location in the tree.
inherited
createState() → State<ParallaxImage>
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.
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, int wrapWidth = 65}) → 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