TreeItemNode<T> class

A concrete tree node implementation that holds data and state.

TreeItemNode represents a data-bearing node in the tree structure with support for hierarchical organization, expansion/collapse state, and selection state. It implements the immutable pattern where state changes return new instances.

Each TreeItemNode contains user data of type T, a list of child nodes, and boolean flags for expansion and selection state. The class provides equality comparison based on all properties and implements proper hash codes.

TreeItemNode supports deep hierarchies through its children list, which can contain other TreeItemNode instances or TreeRootNode containers. The expansion state controls visibility of children in tree views.

Example:

// Create a simple item
TreeItemNode<String> item = TreeItemNode(
  data: 'Document',
  expanded: true,
  selected: false,
  children: [
    TreeItemNode(data: 'Chapter 1'),
    TreeItemNode(data: 'Chapter 2'),
  ],
);

// Update its state
TreeItemNode<String> selected = item.updateState(selected: true);
Inheritance

Constructors

TreeItemNode({required T data, List<TreeNode<T>> children = const [], bool expanded = false, bool selected = false})
Creates a TreeItemNode with the specified data and configuration.

Properties

children → List<TreeNode<T>>
List of child nodes beneath this item in the tree hierarchy.
final
data → T
The data value stored in this tree item.
final
expanded → bool
Whether this item is currently expanded to show its children.
final
hashCode → int
The hash code for this object.
no setteroverride
leaf → bool
Whether this node is a leaf (has no children).
no setterinherited
runtimeType → Type
A representation of the runtime type of the object.
no setterinherited
selected → bool
Whether this item is currently selected.
final

Methods

noSuchMethod(Invocation invocation) → dynamic
Invoked when a nonexistent method or property is accessed.
inherited
toString() → String
A string representation of this object.
override
updateChildren(List<TreeNode<T>> children) → TreeItemNode<T>
Creates a new instance with updated children list.
override
updateState({bool? expanded, bool? selected}) → TreeItemNode<T>
Creates a new instance with updated expansion and/or selection state.
override

Operators

operator ==(Object other) → bool
The equality operator.
override