TreeController<T extends Object> class

A controller for managing the state of a tree structure.

This controller handles:

  • Tree state management (expansion/collapse)
  • Tree traversal (depth-first and breadth-first)
  • Search functionality
  • Parent/ancestor navigation

Example:

class Node {
  Node(this.title, [this.children = const []]);
  final String title;
  final List<Node> children;
  Node? parent;
}

final controller = TreeController<Node>(
  roots: [Node('Root')],
  childrenProvider: (node) => node.children,
  parentProvider: (node) => node.parent,
);
Mixed-in types

Constructors

TreeController({required Iterable<T> roots, required ChildrenProvider<T> childrenProvider, ParentProvider<T>? parentProvider, bool defaultExpansionState = false, bool enableCheckbox = false})
Creates a TreeController.

Properties

areAllRootsCollapsed → bool
Whether all root nodes are collapsed.
no setter
areAllRootsExpanded → bool
Whether all root nodes are expanded.
no setter
checkedNodes → Set<T>
Set of checked nodes (when checkbox is enabled).
latefinal
childrenProvider → ChildrenProvider<T>
Callback to get the children of a node.
final
defaultExpansionState → bool
Default expansion state for nodes.
final
enableCheckbox → bool
Whether checkbox selection is enabled.
final
hashCode → int
The hash code for this object.
no setterinherited
hasListeners → bool
Whether any listeners are currently registered.
no setterinherited
isTreeCollapsed → bool
Whether all nodes in the tree are collapsed.
no setter
isTreeExpanded → bool
Whether all nodes in the tree are expanded.
no setter
parentProvider → ParentProvider<T>
Callback to get the parent of a node.
final
roots ↔ Iterable<T>
The root nodes of the tree.
getter/setter pair
runtimeType → Type
A representation of the runtime type of the object.
no setterinherited
toggledNodes → Set<T>
Set of toggled nodes (expanded if defaultExpansionState is false, collapsed otherwise).
latefinal

Methods

addListener(VoidCallback listener) → void
Register a closure to be called when the object changes.
inherited
breadthFirstSearch({Iterable<T>? startingNodes, ValuePredicate<T>? descendCondition, ValuePredicate<T>? returnCondition, Visitor<T>? onTraverse}) → T?
Traverses the tree in breadth-first order.
checkNodeHasAncestor({required T node, required T potentialAncestor, bool checkForEquality = false}) → bool
Checks if potentialAncestor is an ancestor of node.
clearCheckedNodes() → void
Clears all checked nodes.
collapse(T node) → void
Collapses node.
collapseAll() → void
Collapses all nodes in the tree.
collapseCascading(Iterable<T> nodes) → void
Collapses nodes and all their descendants.
defaultDescendCondition(TreeEntry<T> entry) → bool
Default descend condition for depth-first traversal.
depthFirstTraversal({required Visitor<TreeEntry<T>> onTraverse, ValuePredicate<TreeEntry<T>>? descendCondition, TreeEntry<T>? rootEntry}) → void
Traverses the tree in depth-first order creating TreeEntry instances.
dispose() → void
Discards any resources used by the object.
override
expand(T node) → void
Expands node.
expandAll() → void
Expands all nodes in the tree.
expandAncestors(T node) → void
Expands all ancestors of node.
expandCascading(Iterable<T> nodes) → void
Expands nodes and all their descendants.
getCheckedNodes() → Set<T>
Returns all checked nodes (excluding indeterminate parents).
getExpansionState(T node) → bool
Returns the expansion state of node.
isChecked(T node) → bool
Returns whether node is checked.
isIndeterminate(T node) → bool
Returns whether node is in indeterminate state (some but not all children checked).
noSuchMethod(Invocation invocation) → dynamic
Invoked when a nonexistent method or property is accessed.
inherited
notifyListeners() → void
Call all the registered listeners.
inherited
rebuild() → void
Notifies listeners that the tree structure changed.
removeListener(VoidCallback listener) → void
Remove a previously registered closure from the list of closures that are notified when the object changes.
inherited
Searches the tree for nodes matching predicate.
selectAll() → void
Selects all nodes in the tree (checks all checkboxes).
setCheckboxState(T node, bool checked) → void
Sets the checked state of node and updates children and ancestors.
setCheckedNodes(Set<T> nodes) → void
Sets the checked nodes (useful for initializing selection).
setExpansionState(T node, bool expanded) → void
Sets the expansion state of node.
toggleCheckbox(T node) → void
Toggles the checked state of node and updates children and ancestors.
toggleExpansion(T node) → void
Toggles the expansion state of node.
toString() → String
A string representation of this object.
inherited
unselectAll() → void
Unselects all nodes in the tree (unchecks all checkboxes).

Operators

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