ReorderableList class - widgets library

A scrolling container that allows the user to interactively reorder the list items.

This widget is similar to one created by ListView.builder, and uses an IndexedWidgetBuilder to create each item.

It is up to the application to wrap each child (or an internal part of the child such as a drag handle) with a drag listener that will recognize the start of an item drag and then start the reorder by calling ReorderableListState.startItemDragReorder. This is most easily achieved by wrapping each child in a ReorderableDragStartListener or a ReorderableDelayedDragStartListener. These will take care of recognizing the start of a drag gesture and call the list state's ReorderableListState.startItemDragReorder method.

This widget's ReorderableListState can be used to manually start an item reorder, or cancel a current drag. To refer to the ReorderableListState either provide a GlobalKey or use the static ReorderableList.of method from an item's build method.

Constructors

ReorderableList({Key? key, required IndexedWidgetBuilder itemBuilder, required int itemCount, required ReorderCallback onReorder, void onReorderStart(int index)?, void onReorderEnd(int index)?, double? itemExtent, ItemExtentBuilder? itemExtentBuilder, Widget? prototypeItem, ReorderItemProxyDecorator? proxyDecorator, EdgeInsetsGeometry? padding, Axis scrollDirection = Axis.vertical, bool reverse = false, ScrollController? controller, bool? primary, ScrollPhysics? physics, bool shrinkWrap = false, double anchor = 0.0, double? cacheExtent, DragStartBehavior dragStartBehavior = DragStartBehavior.start, ScrollViewKeyboardDismissBehavior? keyboardDismissBehavior, String? restorationId, Clip clipBehavior = Clip.hardEdge, double? autoScrollerVelocityScalar, ReorderDragBoundaryProvider? dragBoundaryProvider}): Creates a scrolling container that allows the user to interactively reorder the list items.
const

Properties

anchor → double: The relative position of the zero scroll offset.
final
autoScrollerVelocityScalar → double?: The velocity scalar per pixel over scroll.
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
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
dragBoundaryProvider → ReorderDragBoundaryProvider?: A callback used to provide drag boundaries during drag-and-drop reordering.
final
dragStartBehavior → DragStartBehavior: Determines the way that drag start behavior is handled.
final
hashCode → int: The hash code for this object.
no setterinherited
itemBuilder → IndexedWidgetBuilder: Called, as needed, to build list item widgets.
final
itemCount → int: The number of items in the list.
final
itemExtent → double?: If non-null, forces the children to have the given extent in the scroll direction.
final
itemExtentBuilder → ItemExtentBuilder?: If non-null, forces the children to have the corresponding extent returned by the builder.
final
key → Key?: Controls how one widget replaces another widget in the tree.
finalinherited
keyboardDismissBehavior → ScrollViewKeyboardDismissBehavior?: The ScrollViewKeyboardDismissBehavior defines how this ScrollView will dismiss the keyboard automatically.
final
onReorder → ReorderCallback: A callback used by the list to report that a list item has been dragged to a new location in the list and the application should update the order of the items.
final
onReorderEnd → void Function(int index)?: A callback that is called when the dragged item is dropped.
final
onReorderStart → void Function(int index)?: A callback that is called when an item drag has started.
final
padding → EdgeInsetsGeometry?: The amount of space by which to inset the list contents.
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
prototypeItem → Widget?: If non-null, forces the children to have the same extent as the given widget in the scroll direction.
final
proxyDecorator → ReorderItemProxyDecorator?: A callback that allows the app to add an animated decoration around an item when it is being dragged.
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.
no setterinherited
scrollDirection → Axis: The Axis along which the scroll view's offset increases.
final
shrinkWrap → bool: Whether the extent of the scroll view in the scrollDirection should be determined by the contents being viewed.
final

Methods

createElement() → StatefulElement: Creates a StatefulElement to manage this widget's location in the tree.
inherited
createState() → ReorderableListState: Creates the mutable state for this widget at a given location in the tree.
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
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

Operators

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

Static Methods

maybeOf(BuildContext context) → ReorderableListState?: The state from the closest instance of this class that encloses the given context.
of(BuildContext context) → ReorderableListState: The state from the closest instance of this class that encloses the given context.