SliverVariedExtentList class

A sliver that places its box children in a linear array and constrains them to have the corresponding extent returned by itemExtentBuilder.

To learn more about slivers, see CustomScrollView.slivers.

SliverVariedExtentList arranges its children in a line along the main axis starting at offset zero and without gaps. Each child is constrained to the corresponding extent along the main axis and the SliverConstraints.crossAxisExtent along the cross axis.

SliverVariedExtentList is more efficient than SliverList because SliverVariedExtentList does not need to lay out its children to obtain their extent along the main axis. It's a little more flexible than SliverFixedExtentList because this allow the children to have different extents.

See also:

Inheritance

Constructors

SliverVariedExtentList({Key? key, required SliverChildDelegate delegate, required ItemExtentBuilder itemExtentBuilder})
Creates a sliver that places box children with the same main axis extent in a linear array.
const
SliverVariedExtentList.builder({Key? key, required NullableIndexedWidgetBuilder itemBuilder, required ItemExtentBuilder itemExtentBuilder, ChildIndexGetter? findChildIndexCallback, int? itemCount, bool addAutomaticKeepAlives = true, bool addRepaintBoundaries = true, bool addSemanticIndexes = true})
A sliver that places multiple box children in a linear array along the main axis.
SliverVariedExtentList.list({Key? key, required List<Widget> children, required ItemExtentBuilder itemExtentBuilder, bool addAutomaticKeepAlives = true, bool addRepaintBoundaries = true, bool addSemanticIndexes = true})
A sliver that places multiple box children in a linear array along the main axis.

Properties

delegate → SliverChildDelegate
The delegate that provides the children for this widget.
finalinherited
hashCode → int
The hash code for this object.
no setterinherited
itemExtentBuilder → ItemExtentBuilder
The children extent builder.
final
key → Key?
Controls how one widget replaces another widget in the tree.
finalinherited
runtimeType → Type
A representation of the runtime type of the object.
no setterinherited

Methods

createElement() → SliverMultiBoxAdaptorElement
RenderObjectWidgets always inflate to a RenderObjectElement subclass.
inherited
createRenderObject(BuildContext context) → RenderSliverVariedExtentList
Creates an instance of the RenderObject class that this RenderObjectWidget represents, using the configuration described by this RenderObjectWidget.
override
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.
inherited
didUnmountRenderObject(covariant RenderObject renderObject) → void
A render object previously associated with this widget has been removed from the tree. The given RenderObject will be of the same type as returned by this object's createRenderObject.
inherited
estimateMaxScrollOffset(SliverConstraints? constraints, int firstIndex, int lastIndex, double leadingScrollOffset, double trailingScrollOffset) → double?
Returns an estimate of the max scroll extent for all the children.
inherited
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
updateRenderObject(BuildContext context, covariant RenderSliverVariedExtentList renderObject) → void
Copies the configuration described by this RenderObjectWidget to the given RenderObject, which will be of the same type as returned by this object's createRenderObject.
override

Operators

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