ScrollView class Null safety
A widget that scrolls.
Scrollable widgets consist of three pieces:
- A Scrollable widget, which listens for various user gestures and implements the interaction design for scrolling.
- 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.
- One or more slivers, which are widgets that can be composed to created various scrolling effects, such as lists, grids, and expanding headers.
ScrollView helps orchestrate these pieces by creating the Scrollable and the viewport and deferring to its subclass to create the slivers.
To control the initial scroll offset of the scroll view, provide a controller with its ScrollController.initialScrollOffset property set.
See also:
- ListView, which is a commonly used ScrollView that displays a scrolling, linear list of child widgets.
- PageView, which is a scrolling list of child widgets that are each the size of the viewport.
- GridView, which is a ScrollView that displays a scrolling, 2D array of child widgets.
- CustomScrollView, which is a ScrollView that creates custom scroll effects using slivers.
- ScrollNotification and NotificationListener, which can be used to watch the scroll position without using a ScrollController.
- Inheritance
-
- Object
- DiagnosticableTree
- Widget
- StatelessWidget
- ScrollView
- Implementers
Constructors
- ScrollView({Key? key, Axis scrollDirection = Axis.vertical, bool reverse = false, ScrollController? controller, bool? primary, ScrollPhysics? physics, ScrollBehavior? scrollBehavior, bool shrinkWrap = false, Key? center, double anchor = 0.0, double? cacheExtent, int? semanticChildCount, DragStartBehavior dragStartBehavior = DragStartBehavior.start, ScrollViewKeyboardDismissBehavior keyboardDismissBehavior = ScrollViewKeyboardDismissBehavior.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 → ScrollController?
-
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.
- key → Key?
-
Controls how one widget replaces another widget in the tree.
finalinherited
- keyboardDismissBehavior → ScrollViewKeyboardDismissBehavior
-
ScrollViewKeyboardDismissBehavior the 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.
read-onlyinherited
- scrollBehavior → ScrollBehavior?
-
A ScrollBehavior that will be applied to this widget individually.
final
- scrollDirection → Axis
-
The axis along which the scroll view scrolls.
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.
protected">@protected
-
buildViewport(
BuildContext context, ViewportOffset offset, AxisDirection axisDirection, List< Widget> slivers) → Widget -
Build the viewport.
protected">@protected
-
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.protected">@protectedinherited -
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.
protected">@protected
-
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 -
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">@nonVirtualinherited