ReorderableListView class
A list whose items the user can interactively reorder by dragging.
This sample shows by dragging the user can reorder the items of the list. The onReorder parameter is required and will be called when a child widget is dragged to a new position.
link
To create a local project with this code sample, run:
flutter create --sample=material.ReorderableListView.1 mysample
By default, on TargetPlatformVariant.desktop platforms each item will have a drag handle added on top of it that will allow the user to grab it to move the item. On TargetPlatformVariant.mobile, no drag handle will be added, but when the user long presses anywhere on the item it will start moving the item. Displaying drag handles can be controlled with ReorderableListView.buildDefaultDragHandles.
All list items must have a key.
This example demonstrates using the ReorderableListView.proxyDecorator callback to customize the appearance of a list item while it's being dragged.
While a drag is underway, the widget returned by the ReorderableListView.proxyDecorator
callback serves as a "proxy" (a substitute) for the item in the list. The proxy is
created with the original list item as its child. The ReorderableListView.proxyDecorator
callback in this example is similar to the default one except that it changes the
proxy item's background color.
link
To create a local project with this code sample, run:
flutter create --sample=material.ReorderableListView.2 mysample
This example demonstrates using the ReorderableListView.proxyDecorator callback to customize the appearance of a Card while it's being dragged.
The default proxyDecorator wraps the dragged item in a Material widget and animates
its elevation. This example demonstrates how to use the ReorderableListView.proxyDecorator
callback to update the dragged card elevation without inserted a new Material widget.
link
To create a local project with this code sample, run:
flutter create --sample=material.ReorderableListView.3 mysample
- Inheritance
-
- Object
- DiagnosticableTree
- Widget
- StatefulWidget
- ReorderableListView
Constructors
-
ReorderableListView({Key? key, required List<
Widget> children, required ReorderCallback onReorder, void onReorderStart(int index)?, void onReorderEnd(int index)?, double? itemExtent, ItemExtentBuilder? itemExtentBuilder, Widget? prototypeItem, ReorderItemProxyDecorator? proxyDecorator, bool buildDefaultDragHandles = true, EdgeInsets? padding, Widget? header, Axis scrollDirection = Axis.vertical, bool reverse = false, ScrollController? scrollController, 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, double? autoScrollerVelocityScalar}) - Creates a reorderable list from a pre-built list of widgets.
- ReorderableListView.builder({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, bool buildDefaultDragHandles = true, EdgeInsets? padding, Widget? header, Axis scrollDirection = Axis.vertical, bool reverse = false, ScrollController? scrollController, 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, double? autoScrollerVelocityScalar})
-
Creates a reorderable list from widget items that are created on demand.
const
Properties
- anchor → double
-
The relative position of the zero scroll offset.
final
- autoScrollerVelocityScalar → double?
-
The velocity scalar per pixel over scroll.
final
- buildDefaultDragHandles → bool
-
If true: on desktop platforms, a drag handle is stacked over the
center of each item's trailing edge; on mobile platforms, a long
press anywhere on the item starts a drag.
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
- dragStartBehavior → DragStartBehavior
-
Determines the way that drag start behavior is handled.
final
-
A non-reorderable footer item to show after the items of the list.
final
- hashCode → int
-
The hash code for this object.
no setterinherited
- header → Widget?
-
A non-reorderable header item to show before the items of the list.
final
- 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
-
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 → EdgeInsets?
-
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
- scrollController → ScrollController?
-
An object that can be used to control the position to which this scroll
view is scrolled.
final
- 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(
) → State< ReorderableListView> -
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}) → 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