MaterialScrollBehavior class

Describes how Scrollable widgets behave for MaterialApps.

Used by ScrollConfiguration to configure the Scrollable widgets in a subtree.

This class can be extended to further customize a ScrollBehavior for a subtree. For example, overriding ScrollBehavior.getScrollPhysics sets the default ScrollPhysics for Scrollables that inherit this ScrollConfiguration. Overriding ScrollBehavior.buildOverscrollIndicator can be used to add or change the default GlowingOverscrollIndicator decoration, while ScrollBehavior.buildScrollbar can be changed to modify the default Scrollbar.

When looking to easily toggle the default decorations, you can use ScrollBehavior.copyWith instead of creating your own ScrollBehavior class. The scrollbar and overscrollIndicator flags can turn these decorations off.

Setting a MaterialScrollBehavior will apply a GlowingOverscrollIndicator to Scrollable descendants when executing on TargetPlatform.android and TargetPlatform.fuchsia.

When using the desktop platform, if the Scrollable widget scrolls in the Axis.vertical, a Scrollbar is applied.

If the scroll direction is Axis.horizontal scroll views are less discoverable, so consider adding a Scrollbar in these cases, either directly or through the buildScrollbar method.

ThemeData.useMaterial3 specifies the overscroll indicator that is used on TargetPlatform.android, which defaults to true, resulting in a StretchingOverscrollIndicator. Setting ThemeData.useMaterial3 to false will instead use a GlowingOverscrollIndicator.

See also:

  • ScrollBehavior, the default scrolling behavior extended by this class.
Inheritance

Constructors

MaterialScrollBehavior()
Creates a MaterialScrollBehavior that decorates Scrollables with StretchingOverscrollIndicators and Scrollbars based on the current platform and provided ScrollableDetails.
const

Properties

dragDevices Set<PointerDeviceKind>
The device kinds that the scrollable will accept drag gestures from.
no setterinherited
hashCode int
The hash code for this object.
no setterinherited
multitouchDragStrategy MultitouchDragStrategy
Configure the multi-finger drag strategy on multi-touch devices.
no setterinherited
pointerAxisModifiers Set<LogicalKeyboardKey>
A set of LogicalKeyboardKeys that, when any or all are pressed in combination with a PointerDeviceKind.mouse pointer scroll event, will flip the axes of the scroll input.
no setterinherited
runtimeType Type
A representation of the runtime type of the object.
no setterinherited

Methods

buildOverscrollIndicator(BuildContext context, Widget child, ScrollableDetails details) Widget
Applies a GlowingOverscrollIndicator to the child widget on TargetPlatform.android and TargetPlatform.fuchsia.
override
buildScrollbar(BuildContext context, Widget child, ScrollableDetails details) Widget
Applies a RawScrollbar to the child widget on desktop platforms.
override
copyWith({bool? scrollbars, bool? overscroll, Set<PointerDeviceKind>? dragDevices, MultitouchDragStrategy? multitouchDragStrategy, Set<LogicalKeyboardKey>? pointerAxisModifiers, ScrollPhysics? physics, TargetPlatform? platform}) ScrollBehavior
Creates a copy of this ScrollBehavior, making it possible to easily toggle scrollbar and overscrollIndicator effects.
inherited
getPlatform(BuildContext context) TargetPlatform
The platform whose scroll physics should be implemented.
override
getScrollPhysics(BuildContext context) ScrollPhysics
The scroll physics to use for the platform given by getPlatform.
inherited
noSuchMethod(Invocation invocation) → dynamic
Invoked when a nonexistent method or property is accessed.
inherited
shouldNotify(covariant ScrollBehavior oldDelegate) bool
Called whenever a ScrollConfiguration is rebuilt with a new ScrollBehavior of the same runtimeType.
inherited
toString() String
A string representation of this object.
inherited
velocityTrackerBuilder(BuildContext context) GestureVelocityTrackerBuilder
Specifies the type of velocity tracker to use in the descendant Scrollables' drag gesture recognizers, for estimating the velocity of a drag gesture.
inherited

Operators

operator ==(Object other) bool
The equality operator.
inherited