TreeDragTarget<T extends Object> class

A DragTarget wrapper that provides some additional tree view capabilities like auto toggle expansion on hover.

Usage:

@override
Widget build(BuildContext context) {
  return TreeDragTarget<Node>(
    // The node that will receive the drop from dragging nodes.
    node: entry.node,

    // The following callback is used to apply the changes to the tree
    // structure when the dragging node is accepted by this target node.
    onNodeAccepted: (TreeDragAndDropDetails<Node> details) { },

    // If details is provided, there's a [TreeDraggable] currently hovering
    // this drag target, add some decoration to the tree node tile to show
    // to the user what will happen when they drop the node in this target.
    builder: (BuildContext context, TreeDragAndDropDetails<Node>? details) {
      if (details != null) {
        return MyDecoratedTreeNodeTile();
      }
      return MyTreeNodeTile();
    },
  ),
}
Inheritance

Constructors

TreeDragTarget({Key? key, required T node, required TreeDraggableBuilder<T> builder, required TreeDragTargetNodeAccepted<T> onNodeAccepted, DragTargetWillAcceptWithDetails<T>? onWillAcceptWithDetails, bool toggleExpansionOnHover = true, Duration toggleExpansionDelay = const Duration(seconds: 1), bool canToggleExpansion = true, @Deprecated('Use onWillAcceptWithDetails instead.') DragTargetWillAccept<T>? onWillAccept, @Deprecated('Use onAcceptWithDetails instead.') DragTargetAccept<T>? onAccept, DragTargetAcceptWithDetails<T>? onAcceptWithDetails, DragTargetLeave<T>? onLeave, DragTargetMove<T>? onMove, HitTestBehavior hitTestBehavior = HitTestBehavior.translucent})
Creates a TreeDragTarget.
const

Properties

builder → TreeDraggableBuilder<T>
Called to build the contents of this widget.
final
canToggleExpansion → bool
Whether node can have its expansion state toggled when it is being hovered by another dragging tree node.
final
hashCode → int
The hash code for this object.
no setterinherited
hitTestBehavior → HitTestBehavior
How to behave during hit testing.
final
key → Key?
Controls how one widget replaces another widget in the tree.
finalinherited
node → T
The tree node that is going to receive the drop of a TreeDraggable.
final
onAccept → DragTargetAccept<T>?
Called when an acceptable piece of data was dropped over this drag target.
final
onAcceptWithDetails → DragTargetAcceptWithDetails<T>?
Called when an acceptable piece of data was dropped over this drag target. It will not be called if data is null.
final
onLeave → DragTargetLeave<T>?
Called when a given piece of data being dragged over this target leaves the target.
final
onMove → DragTargetMove<T>?
Called when a Draggable moves within this DragTarget.
final
onNodeAccepted → TreeDragTargetNodeAccepted<T>
Called when a dragging node was successfully dropped onto this drag target.
final
onWillAccept → DragTargetWillAccept<T>?
Called to determine whether this widget is interested in receiving a given piece of data being dragged over this drag target.
final
onWillAcceptWithDetails → DragTargetWillAcceptWithDetails<T>?
Called to determine whether this widget is interested in receiving a given piece of data being dragged over this drag target.
final
runtimeType → Type
A representation of the runtime type of the object.
no setterinherited
toggleExpansionDelay → Duration
The Duration to wait before automatically toggling the expansion state of node when it is being hovered by another dragging tree node.
final
toggleExpansionOnHover → bool
Whether to automatically toggle the expansion state of node when it is being hovered by another dragging tree node.
final

Methods

createElement() → StatefulElement
Creates a StatefulElement to manage this widget's location in the tree.
inherited
createState() → State<TreeDragTarget<T>>
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