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use crate::tree::{
traverse::{next_start, Traverse},
NodeId, Tree,
};
use std::collections::HashSet;
#[derive(Default)]
pub struct TreeState {
pub selected: Option<NodeId>,
pub offset: usize,
pub marked: HashSet<NodeId>,
pub active: Option<NodeId>,
}
impl TreeState {
/// Sets the node with the given `id` as the selected item.
///
/// Sets to `None` if no node is selected. Expands ancestor nodes if they are not expanded.
/// Aborts if the node is detached from the root node.
///
/// # Examples
/// ```
/// use bawa::tree::Tree;
/// use bawa::tree::NodeId;
/// use bawa::tree::TreeState;
///
/// let mut tree = Tree::default();
///
/// let r = tree.add_value("r");
/// let a = tree.add_value("a");
/// let a_b = tree.add_value("b");
///
/// tree.append(r, a);
/// tree.append(a, a_b);
///
/// let mut state = TreeState::default();
///
/// assert!(!tree[a].is_expanded());
///
/// state.select(Some(a_b), &mut tree);
///
/// assert!(tree[a].is_expanded());
/// ```
pub fn select<T>(&mut self, id: Option<NodeId>, tree: &mut Tree<T>) {
if let Some(id) = id {
if tree.get(id).is_none() || tree.detached_from_root(id) {
return;
}
for id in tree.ancestors(id).collect::<Vec<NodeId>>() {
tree[id].expanded = Some(true);
}
}
self.select_unchecked(id);
}
/// Sets the node with the given `id` as the selected item. Aborts if trying to select the root
/// node.
///
/// Sets to `None` if no node is selected. Doesn't ensure that the ancestor nodes are expanded.
///
/// # Examples
/// ```
/// use bawa::tree::TreeState;
/// use bawa::tree::NodeId;
///
/// let mut state = TreeState::default();
/// state.select_unchecked(Some(NodeId::new(1)));
/// ```
pub fn select_unchecked(&mut self, id: Option<NodeId>) {
if matches!(id, Some(id) if id != NodeId::root()) {
self.selected = id;
}
}
pub fn mark(&mut self, id: NodeId) -> bool {
self.marked.insert(id)
}
pub fn unmark(&mut self, id: NodeId) -> bool {
self.marked.remove(&id)
}
/// Selects the next visible item or the first one if no item is selected.
///
/// # Examples
///
/// ```
/// use bawa::tree::Tree;
/// use bawa::tree::TreeState;
///
/// let mut tree = Tree::default();
/// let r = tree.add_value("r");
/// let a = tree.add_value("a");
/// let b = tree.add_value("b");
/// let a_c = tree.add_value("c");
/// let a_c_d = tree.add_value("d");
/// tree.append(r, a);
/// tree.append(a, a_c);
/// tree.append(a_c, a_c_d);
/// tree.append(r, b);
///
/// let mut state = TreeState::default();
/// tree[a].expanded = Some(true);
///
/// state.select_next(&tree);
/// assert_eq!(state.selected, Some(a));
/// state.select_next(&tree);
/// assert_eq!(state.selected, Some(a_c));
/// state.select_next(&tree);
/// assert_eq!(state.selected, Some(b));
/// state.select_next(&tree);
/// assert_eq!(state.selected, Some(a));
/// tree[a].toggle_fold();
/// state.select_next(&tree);
/// assert_eq!(state.selected, Some(b));
/// ```
pub fn select_next<T>(&mut self, tree: &Tree<T>) {
if let Some(id) = self.selected {
self.selected = next_start(
&mut Traverse::new(NodeId::root(), tree)
.visible()
.from(id)
.skip(1),
);
}
if self.selected.is_none() {
self.select_first(tree);
}
}
/// Selects the previous visible item or the last one if no item is selected.
///
/// # Examples
///
/// ```
/// use bawa::tree::Tree;
/// use bawa::tree::TreeState;
///
/// let mut tree = Tree::default();
///
/// let r = tree.add_value("r");
/// let a = tree.add_value("a");
/// let b = tree.add_value("b");
/// let a_c = tree.add_value("c");
/// let a_c_d = tree.add_value("d");
///
/// tree.append(r, a);
/// tree.append(a, a_c);
/// tree.append(a_c, a_c_d);
/// tree.append(r, b);
///
/// let mut state = TreeState::default();
/// tree[a].expanded = Some(true);
///
/// state.select_prev(&tree);
/// assert_eq!(state.selected, Some(b));
/// state.select_prev(&tree);
/// assert_eq!(state.selected, Some(a_c));
/// state.select_prev(&tree);
/// assert_eq!(state.selected, Some(a));
/// state.select_prev(&tree);
/// assert_eq!(state.selected, Some(b));
/// tree[a].toggle_fold();
/// state.select_prev(&tree);
/// assert_eq!(state.selected, Some(a));
/// ```
pub fn select_prev<T>(&mut self, tree: &Tree<T>) {
if let Some(id) = self.selected {
self.selected = next_start(
&mut Traverse::new(NodeId::root(), tree)
.visible()
.to(id)
.rev()
.skip(1),
);
}
if self.selected.is_none() {
self.select_last(tree);
}
}
/// Selects the first item of the tree.
///
/// # Examples
///
/// ```
/// use bawa::tree::Tree;
/// use bawa::tree::TreeState;
///
/// 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);
///
/// let mut state = TreeState::default();
/// state.select_first(&tree);
///
/// assert_eq!(state.selected, Some(a));
/// ```
pub fn select_first<T>(&mut self, tree: &Tree<T>) {
self.selected = tree.root().and_then(|node| node.first_child);
}
/// Selects the last visible item of the tree.
///
/// # Examples
///
/// ```
/// use bawa::tree::Tree;
/// use bawa::tree::TreeState;
///
/// let mut tree = Tree::default();
///
/// let r = tree.add_value("r");
/// let a = tree.add_value("a");
/// let b = tree.add_value("b");
/// let b_c = tree.add_value("c");
///
/// tree.append(r, a);
/// tree.append(r, b);
/// tree.append(b, b_c);
///
/// let mut state = TreeState::default();
/// tree[b].expanded = Some(true);
/// state.select_last(&tree);
///
/// assert_eq!(state.selected, Some(b_c));
/// ```
pub fn select_last<T>(&mut self, tree: &Tree<T>) {
self.selected = std::iter::successors(tree.root().and_then(|node| node.last_child), |id| {
tree.get(*id)
.filter(|node| node.is_expanded())
.and_then(|node| node.last_child)
})
.last();
}
}