SliverPrototypeExtentList class

A sliver that places its box children in a linear array and constrains them to have the same extent as a prototype item along the main axis.

To learn more about slivers, see CustomScrollView.slivers.

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

SliverPrototypeExtentList is more efficient than SliverList because SliverPrototypeExtentList 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 there's no need to determine the appropriate item extent in pixels.

See also:

  • SliverFixedExtentList, whose children are forced to a given pixel extent.
  • SliverVariedExtentList, which supports children with varying (but known upfront) extents.
  • SliverList, which does not require its children to have the same extent in the main axis.
  • SliverFillViewport, which sizes its children based on the size of the viewport, regardless of what else is in the scroll view.
Inheritance

Constructors

SliverPrototypeExtentList({Key? key, required SliverChildDelegate delegate, required Widget prototypeItem})
Creates a sliver that places its box children in a linear array and constrains them to have the same extent as a prototype item along the main axis.
const
SliverPrototypeExtentList.builder({Key? key, required NullableIndexedWidgetBuilder itemBuilder, required Widget prototypeItem, ChildIndexGetter? findChildIndexCallback, int? itemCount, bool addAutomaticKeepAlives = true, bool addRepaintBoundaries = true, bool addSemanticIndexes = true})
A sliver that places its box children in a linear array and constrains them to have the same extent as a prototype item along the main axis.
SliverPrototypeExtentList.list({Key? key, required List<Widget> children, required Widget prototypeItem, 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
key → Key?
Controls how one widget replaces another widget in the tree.
finalinherited
prototypeItem → Widget
Defines the main axis extent of all of this sliver's children.
final
runtimeType → Type
A representation of the runtime type of the object.
no setterinherited

Methods

createElement() → SliverMultiBoxAdaptorElement
RenderObjectWidgets always inflate to a RenderObjectElement subclass.
override
createRenderObject(BuildContext context) → RenderSliverMultiBoxAdaptor
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}) → 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 RenderObject 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.
inherited

Operators

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