ReorderableList class Null safety
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.
See also:
- SliverReorderableList, a sliver list that allows the user to reorder its items.
- ReorderableListView, a Material Design list that allows the user to reorder its items.
- Inheritance
-
- Object
- DiagnosticableTree
- Widget
- StatefulWidget
- ReorderableList
Constructors
- ReorderableList({Key? key, required IndexedWidgetBuilder itemBuilder, required int itemCount, required ReorderCallback onReorder, void onReorderStart(int index)?, void onReorderEnd(int index)?, double? itemExtent, 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 = ScrollViewKeyboardDismissBehavior.manual, String? restorationId, Clip clipBehavior = Clip.hardEdge})
-
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
- 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
- dragStartBehavior → DragStartBehavior
-
Determines the way that drag start behavior is handled.
final
- hashCode → int
- The hash code for this object.
- 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
- key → Key?
-
Controls how one widget replaces another widget in the tree.
finalinherited
- keyboardDismissBehavior → ScrollViewKeyboardDismissBehavior
-
ScrollViewKeyboardDismissBehavior the 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.
read-onlyinherited
- scrollDirection → Axis
-
The axis along which the scroll view scrolls.
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.protected">@protectedinherited -
debugFillProperties(
DiagnosticPropertiesBuilder properties) → void -
Add additional properties associated with the node.
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
Operators
-
operator ==(
Object other) → bool -
The equality operator.
nonVirtual">@nonVirtualinherited
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.