Files
managarr-tree-widget/src/flatten.rs

116 lines
3.0 KiB
Rust

use std::collections::HashSet;
use crate::tree_item::TreeItem;
use ratatui::text::ToText;
/// A flattened item of all visible [`TreeItem`]s.
///
/// Generated via [`TreeState::flatten`](crate::TreeState::flatten).
#[must_use]
pub struct Flattened<'a, Identifier, T>
where
Identifier: Clone + PartialEq + Eq + core::hash::Hash,
T: ToText + Clone + Default,
{
pub identifier: Vec<Identifier>,
pub item: &'a TreeItem<Identifier, T>,
}
impl<'a, Identifier, T> Flattened<'a, Identifier, T>
where
Identifier: Clone + PartialEq + Eq + core::hash::Hash,
T: ToText + Clone + Default,
{
/// Zero based depth. Depth 0 means top level with 0 indentation.
#[must_use]
pub fn depth(&self) -> usize {
self.identifier.len() - 1
}
}
/// Get a flat list of all visible [`TreeItem`]s.
///
/// `current` starts empty: `&[]`
#[must_use]
pub fn flatten<'a, Identifier, T>(
open_identifiers: &HashSet<Vec<Identifier>>,
items: &'a [TreeItem<Identifier, T>],
current: &[Identifier],
) -> Vec<Flattened<'a, Identifier, T>>
where
Identifier: Clone + PartialEq + Eq + core::hash::Hash,
T: ToText + Clone + Default,
{
let mut result = Vec::new();
for item in items {
let mut child_identifier = current.to_vec();
child_identifier.push(item.identifier.clone());
let child_result = open_identifiers
.contains(&child_identifier)
.then(|| flatten(open_identifiers, &item.children, &child_identifier));
result.push(Flattened {
identifier: child_identifier,
item,
});
if let Some(mut child_result) = child_result {
result.append(&mut child_result);
}
}
result
}
#[test]
fn depth_works() {
let mut open = HashSet::new();
open.insert(vec!["b"]);
open.insert(vec!["b", "d"]);
let depths = flatten(&open, &TreeItem::example(), &[])
.into_iter()
.map(|flattened| flattened.depth())
.collect::<Vec<_>>();
assert_eq!(depths, [0, 0, 1, 1, 2, 2, 1, 0]);
}
#[cfg(test)]
fn flatten_works(open: &HashSet<Vec<&'static str>>, expected: &[&str]) {
let items = TreeItem::example();
let result = flatten(open, &items, &[]);
let actual = result
.into_iter()
.map(|flattened| flattened.identifier.into_iter().last().unwrap())
.collect::<Vec<_>>();
assert_eq!(actual, expected);
}
#[test]
fn flatten_nothing_open_is_top_level() {
let open = HashSet::new();
flatten_works(&open, &["a", "b", "h"]);
}
#[test]
fn flatten_wrong_open_is_only_top_level() {
let mut open = HashSet::new();
open.insert(vec!["a"]);
open.insert(vec!["b", "d"]);
flatten_works(&open, &["a", "b", "h"]);
}
#[test]
fn flatten_one_is_open() {
let mut open = HashSet::new();
open.insert(vec!["b"]);
flatten_works(&open, &["a", "b", "c", "d", "g", "h"]);
}
#[test]
fn flatten_all_open() {
let mut open = HashSet::new();
open.insert(vec!["b"]);
open.insert(vec!["b", "d"]);
flatten_works(&open, &["a", "b", "c", "d", "e", "f", "g", "h"]);
}