ExtendedScrollView class abstract

A widget that scrolls.

Scrollable widgets consist of three pieces:

  1. A ExtendedScrollable widget, which listens for various user gestures and implements the interaction design for scrolling.
  2. A viewport widget, such as Viewport or ShrinkWrappingViewport, which implements the visual design for scrolling by displaying only a portion of the widgets inside the scroll view.
  3. One or more slivers, which are widgets that can be composed to created various scrolling effects, such as lists, grids, and expanding headers.

ExtendedScrollView helps orchestrate these pieces by creating the ExtendedScrollable and the viewport and deferring to its subclass to create the slivers.

To learn more about slivers, see ExtendedCustomScrollView.slivers.

To control the initial scroll offset of the scroll view, provide a controller with its ExtendedScrollController.initialScrollOffset property set.

See also:

Inheritance
Implementers

Constructors

ExtendedScrollView.new({Key? key, Axis scrollDirection = Axis.vertical, bool reverse = false, ExtendedScrollController? controller, bool? primary, ScrollPhysics? physics, ExtendedScrollBehavior? scrollBehavior, bool shrinkWrap = false, Key? center, double anchor = 0.0, double? cacheExtent, int? semanticChildCount, DragStartBehavior dragStartBehavior = DragStartBehavior.start, ExtendedScrollViewKeyboardDismissBehavior keyboardDismissBehavior = ExtendedScrollViewKeyboardDismissBehavior.manual, String? restorationId, Clip clipBehavior = Clip.hardEdge})
Creates a widget that scrolls.
const

Properties

anchor → double
The relative position of the zero scroll offset.
final
cacheExtent → double?
The viewport has an area before and after the visible area to cache items that are about to become visible when the user scrolls.
final
center → Key?
The first child in the GrowthDirection.forward growth direction.
final
clipBehavior → Clip
The content will be clipped (or not) according to this option.
final
controller → ExtendedScrollController?
An object that can be used to control the position to which this scroll view is scrolled.
final
dragStartBehavior → DragStartBehavior
Determines the way that drag start behavior is handled.
final
hashCode → int
The hash code for this object.
no setterinherited
key → Key?
Controls how one widget replaces another widget in the tree.
finalinherited
keyboardDismissBehavior → ExtendedScrollViewKeyboardDismissBehavior
The ScrollViewKeyboardDismissBehavior defines how this ScrollView will dismiss the keyboard automatically.
final
physics → ScrollPhysics?
How the scroll view should respond to user input.
final
primary → bool?
Whether this is the primary scroll view associated with the parent PrimaryScrollController.
final
restorationId → String?
Restoration ID to save and restore the scroll offset of the scrollable.
final
reverse → bool
Whether the scroll view scrolls in the reading direction.
final
runtimeType → Type
A representation of the runtime type of the object.
no setterinherited
scrollBehavior → ExtendedScrollBehavior?
ExtendedScrollBehaviors also provide ScrollPhysics. If an explicit ScrollPhysics is provided in physics, it will take precedence, followed by scrollBehavior, and then the inherited ancestor ExtendedScrollBehavior.
final
scrollDirection → Axis
The Axis along which the scroll view's offset increases.
final
semanticChildCount → int?
The number of children that will contribute semantic information.
final
shrinkWrap → bool
Whether the extent of the scroll view in the scrollDirection should be determined by the contents being viewed.
final

Methods

build(BuildContext context) → Widget
Describes the part of the user interface represented by this widget.
override
buildSlivers(BuildContext context) → List<Widget>
Build the list of widgets to place inside the viewport.
buildViewport(BuildContext context, ViewportOffset offset, AxisDirection axisDirection, List<Widget> slivers) → Widget
Build the viewport.
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.
override
getDirection(BuildContext context) → AxisDirection
Returns the AxisDirection in which the scroll view scrolls.
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