Scrollable class

A widget that scrolls.

Scrollable implements the interaction model for a scrollable widget, including gesture recognition, but does not have an opinion about how the viewport, which actually displays the children, is constructed.

It's rare to construct a Scrollable directly. Instead, consider ListView or GridView, which combine scrolling, viewporting, and a layout model. To combine layout models (or to use a custom layout mode), consider using CustomScrollView.

The static Scrollable.of and Scrollable.ensureVisible functions are often used to interact with the Scrollable widget inside a ListView or a GridView.

To further customize scrolling behavior with a Scrollable:

You can provide a viewportBuilder to customize the child model. For example, SingleChildScrollView uses a viewport that displays a single box child whereas CustomScrollView uses a Viewport or a ShrinkWrappingViewport, both of which display a list of slivers.
You can provide a custom ScrollController that creates a custom ScrollPosition subclass. For example, PageView uses a PageController, which creates a page-oriented scroll position subclass that keeps the same page visible when the Scrollable resizes.

Constructors

Scrollable({Key key, AxisDirection axisDirection: AxisDirection.down, ScrollController controller, ScrollPhysics physics, @required ViewportBuilder viewportBuilder, bool excludeFromSemantics: false, int semanticChildCount }): Creates a widget that scrolls. [...]
const

Properties

axis → Axis: The axis along which the scroll view scrolls. [...]
read-only
axisDirection → AxisDirection: The direction in which this widget scrolls. [...]
final
controller → ScrollController: An object that can be used to control the position to which this widget is scrolled. [...]
final
excludeFromSemantics → bool: Whether the scroll actions introduced by this Scrollable are exposed in the semantics tree. [...]
final
physics → ScrollPhysics: How the widgets should respond to user input. [...]
final
semanticChildCount → int: The number of children that will contribute semantic information. [...]
final
viewportBuilder → ViewportBuilder: Builds the viewport through which the scrollable content is displayed. [...]
final
hashCode → int: The hash code for this object. [...]
read-only, inherited
key → Key: Controls how one widget replaces another widget in the tree. [...]
final, inherited
runtimeType → Type: A representation of the runtime type of the object.
read-only, inherited

Methods

createState() → ScrollableState: 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 toStringDeep. [...]
inherited
toString({DiagnosticLevel minLevel: DiagnosticLevel.debug }) → 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 ==(dynamic other) → bool: The equality operator. [...]
inherited

Static Methods

ensureVisible(BuildContext context, { double alignment: 0.0, Duration duration: Duration.zero, Curve curve: Curves.ease }) → Future<void>: Scrolls the scrollables that enclose the given context so as to make the given context visible.
of(BuildContext context) → ScrollableState: The state from the closest instance of this class that encloses the given context. [...]