Struct ItemTree 

pub struct ItemTree<T>
where
    T: Clone + Debug + Send + Sync + 'static,
{ /* private fields */ }

Generic in-memory item tree (S11).

T: Clone + Debug + Send + Sync + 'static mirrors the iced reference implementation’s bounds. No additional bounds are imposed by ItemTree itself; the optional display_fn (needed for search and label rendering) is set at construction time via Self::with_display.

Implementations

impl<T> ItemTree<T>

where T: Clone + Debug + Send + Sync + 'static,

pub fn set_tree(&mut self, root: ItemNode<T>)

Replace the entire tree content with a new root (S11.4).

State is preserved for any NodeId that survives across the replacement, regardless of whether the node moved to a new position (S11.5). Disappeared keys are silently dropped; their selection and expansion state is discarded.

After set_tree, if a display_fn is set and a search is active, search visibility is recomputed automatically.

pub fn on_toggled(&mut self, id: NodeId)

Expand or collapse the node identified by id.

Leaves (nodes with no children) are silently ignored (S11.2).

pub fn on_selected(&mut self, id: NodeId, mode: SelectionMode)

Apply a selection gesture (S11.7 → S6.x analogue).

pub fn handle_key(&self, key: TreeKey, mods: Modifiers) -> Option<ItemTreeEvent>

Translate a key press into an ItemTreeEvent, or None when the key is unbound.

Read-only — does not mutate self. The caller dispatches the returned event back through Self::on_toggled / Self::on_selected.

pub fn set_search_query(&mut self, query: &str)

Activate or update the incremental search filter (S11.6).

Requires a display_fn to have been set at construction time. Empty string clears the search.

pub fn clear_search(&mut self)

Clear the active search.

impl<T> ItemTree<T>

where T: Clone + Debug + Send + Sync + 'static,

pub fn on_drag_msg(&mut self, msg: ItemDragMsg) -> ItemDragOutcome

Drive the drag state machine (S11.9–S11.16).

Returns an ItemDragOutcome describing the side effect the host must handle: a deferred click selection, or a completed drop intent. The widget mutates no node structure — the host rebuilds its model from Completed { sources, target, position } and calls Self::set_tree.

All variants are no-ops when drag-and-drop is disabled or no drag is in progress, so stray or out-of-order messages are harmless.

impl<T> ItemTree<T>

where T: Clone + Debug + Send + Sync + 'static,

pub fn new() -> ItemTree<T>

Create an empty tree with no display function.

pub fn with_display( self, f: impl Fn(&T) -> String + Send + Sync + 'static, ) -> ItemTree<T>

Builder: attach a display function used for search and label rendering.

The function maps &T → String. Without it, Self::set_search_query is a no-op and all VisibleItem::labels are empty.

pub fn with_drag_and_drop(self, enabled: bool) -> ItemTree<T>

Builder: enable drag-and-drop reorder/nest (opt-in, S11.9). Off by default; when disabled, mouse press selects directly.

impl<T> ItemTree<T>

where T: Clone + Debug + Send + Sync + 'static,

pub fn visible_rows(&self) -> Vec<VisibleItem>

Ordered list of currently visible rows.

In normal mode: the root and all descendants in expanded branches. In search mode: matches and all their ancestors, regardless of expansion state (S11.6 → S9.3 analogue).

pub fn is_selected(&self, id: NodeId) -> bool

true iff id is in the current selection set.

pub fn selected_ids(&self) -> &[NodeId]

Ordered selected IDs.

pub fn active_id(&self) -> Option<NodeId>

The keyboard-focus / active node.

pub fn search_state(&self) -> Option<&ItemSearchState>

Active search session, or None.

pub fn search_query(&self) -> Option<&str>

Current search query, or None.

pub fn search_match_count(&self) -> usize

Direct match count (S11.6 → S9.8 analogue).

pub fn node_count(&self) -> usize

Number of nodes currently in the tree.

pub fn is_drag_and_drop_enabled(&self) -> bool

Whether drag-and-drop is enabled (S11.9).

pub fn is_dragging(&self) -> bool

Whether a drag is currently in progress.

pub fn drag_sources(&self) -> &[NodeId]

The nodes being dragged (pre-order), or an empty slice when idle.

pub fn drop_target(&self) -> Option<(NodeId, DropPosition)>

The current valid drop target and position, or None.

pub fn is_expanded(&self, id: NodeId) -> Option<bool>

Return whether the node identified by id is currently expanded. Returns None if the id is not in the tree.

Trait Implementations

impl<T> Clone for ItemTree<T>

where T: Clone + Debug + Send + Sync + 'static,

fn clone(&self) -> ItemTree<T>

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<T> Debug for ItemTree<T>

where T: Clone + Debug + Send + Sync + 'static,

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.

impl<T> Default for ItemTree<T>

where T: Clone + Debug + Send + Sync + 'static,

fn default() -> ItemTree<T>

Returns the “default value” for a type.