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use std::ops::{Deref, DerefMut};
use super::id::NodeId;
pub struct Node<T> {
pub(super) parent: Option<NodeId>,
pub(super) previous_sibling: Option<NodeId>,
pub(super) next_sibling: Option<NodeId>,
pub(super) first_child: Option<NodeId>,
pub(super) last_child: Option<NodeId>,
pub expanded: Option<bool>,
pub value: T,
}
impl<T> Node<T> {
/// Creates a node with the given value, with its relations set to `None`.
pub fn new(value: T) -> Self {
Self {
parent: None,
previous_sibling: None,
next_sibling: None,
first_child: None,
last_child: None,
expanded: None,
value,
}
}
/// Returns the `id` of the parent node or `None` if the node is a root of the tree.
///
/// # Examples
///
/// ```
/// # use bawa::tree::Tree;
///
/// let mut tree = Tree::default();
///
/// let r = tree.add_value("r");
/// let a = tree.add_value("a");
/// tree.append(r, a);
///
/// assert_eq!(tree[a].parent(), Some(r));
/// assert!(tree[r].parent().is_none());
/// ```
pub fn parent(&self) -> Option<NodeId> {
self.parent
}
/// Returns the `id` of the previous sibling or `None` if the node is the first child of its
/// parent.
///
/// # Examples
///
/// ```
/// # use bawa::tree::Tree;
///
/// let mut tree = Tree::default();
///
/// let r = tree.add_value("r");
/// let a = tree.add_value("a");
/// let b = tree.add_value("b");
/// tree.append(r, a);
/// tree.append(r, b);
///
/// assert_eq!(tree[b].previous_sibling(), Some(a));
/// assert!(tree[a].previous_sibling().is_none());
/// ```
pub fn previous_sibling(&self) -> Option<NodeId> {
self.previous_sibling
}
/// Returns the `id` of the next sibling or `None` if the node is the last child of its
/// parent.
///
/// # Examples
///
/// ```
/// # use bawa::tree::Tree;
///
/// let mut tree = Tree::default();
///
/// let r = tree.add_value("r");
/// let a = tree.add_value("a");
/// let b = tree.add_value("b");
/// tree.append(r, a);
/// tree.append(r, b);
///
/// assert_eq!(tree[a].next_sibling(), Some(b));
/// assert!(tree[b].next_sibling().is_none());
/// ```
pub fn next_sibling(&self) -> Option<NodeId> {
self.next_sibling
}
/// Returns the `id` of the first child or `None` if the node has no children.
///
/// # Examples
///
/// ```
/// # use bawa::tree::Tree;
///
/// let mut tree = Tree::default();
///
/// let r = tree.add_value("r");
/// let a = tree.add_value("a");
/// let b = tree.add_value("b");
///
/// assert!(tree[r].first_child().is_none());
///
/// tree.append(r, a);
/// tree.append(r, b);
///
/// assert_eq!(tree[r].first_child(), Some(a));
/// ```
pub fn first_child(&self) -> Option<NodeId> {
self.first_child
}
/// Returns the `id` of the last child or `None` if the node has no children.
///
/// # Examples
///
/// ```
/// # use bawa::tree::Tree;
///
/// let mut tree = Tree::default();
///
/// let r = tree.add_value("r");
/// let a = tree.add_value("a");
/// let b = tree.add_value("b");
///
/// assert!(tree[r].last_child().is_none());
///
/// tree.append(r, a);
/// tree.append(r, b);
///
/// assert_eq!(tree[r].last_child(), Some(b));
/// ```
pub fn last_child(&self) -> Option<NodeId> {
self.last_child
}
pub fn has_children(&self) -> bool {
self.first_child.is_some()
}
pub fn non_root_parent(&self) -> Option<NodeId> {
self.parent.filter(|id| *id != NodeId::root())
}
pub fn is_expanded(&self) -> bool {
self.expanded.is_some_and(|b| b)
}
pub fn is_collapsed(&self) -> bool {
self.expanded.is_some_and(|b| !b)
}
pub fn toggle_fold(&mut self) {
self.expanded = self.expanded.map(|t| !t);
}
}
impl<T> Deref for Node<T> {
type Target = T;
fn deref(&self) -> &Self::Target {
&self.value
}
}
impl<T> DerefMut for Node<T> {
fn deref_mut(&mut self) -> &mut Self::Target {
&mut self.value
}
}