SliverPrototypeExtentList class Null safety
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 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 itemExtent is a pixel value.
- 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.
- SliverList, which shows a list of variable-sized children in a viewport.
- Inheritance
-
- Object
- DiagnosticableTree
- Widget
- RenderObjectWidget
- SliverWithKeepAliveWidget
- SliverMultiBoxAdaptorWidget
- SliverPrototypeExtentList
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
Properties
- delegate → SliverChildDelegate
-
The delegate that provides the children for this widget.
finalinherited
- hashCode → int
- The hash code for this object.
- 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.
read-onlyinherited
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.protected">@protectedinherited -
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.
protected">@protectedinherited
-
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 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
-
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.
protected">@protectedinherited
Operators
-
operator ==(
Object other) → bool -
The equality operator.
nonVirtual">@nonVirtualinherited