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:

  1. 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.

  2. 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.

See also:

Inheritance

Constructors

Scrollable({Key key, AxisDirection axisDirection: AxisDirection.down, ScrollController controller, ScrollPhysics physics, @required ViewportBuilder viewportBuilder })
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
physics ScrollPhysics
How the widgets should respond to user input. [...]
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. [...]
debugFillProperties(DiagnosticPropertiesBuilder description) → void
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 ==(other) bool
The equality operator. [...]
inherited

Static Methods

ensureVisible(BuildContext context, { double alignment: 0.0, Duration duration: Duration.ZERO, Curve curve: Curves.ease }) Future<Null>
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. [...]