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

360 lines
12 KiB
Rust

use ratatui::layout::{Position, Rect};
use ratatui::text::ToText;
use std::collections::HashSet;
use std::fmt::Display;
use std::hash::Hash;
use crate::flatten::{flatten, Flattened};
use crate::tree_item::TreeItem;
/// Keeps the state of what is currently selected and what was opened in a [`Tree`](crate::Tree).
///
/// # Example
///
/// ```
/// # use managarr_tree_widget::TreeState;
///
/// let mut state = TreeState::default();
/// ```
#[must_use]
#[derive(Debug, Default)]
pub struct TreeState {
pub(super) offset: usize,
pub(super) opened: HashSet<Vec<u64>>,
pub(super) selected: Vec<u64>,
pub(super) ensure_selected_in_view_on_next_render: bool,
pub(super) last_area: Rect,
pub(super) last_biggest_index: usize,
/// All identifiers open on last render
pub(super) last_identifiers: Vec<Vec<u64>>,
/// Identifier rendered at `y` on last render
pub(super) last_rendered_identifiers: Vec<(u16, Vec<u64>)>,
}
impl TreeState {
#[must_use]
pub const fn get_offset(&self) -> usize {
self.offset
}
#[must_use]
#[deprecated = "Use self.opened()"]
pub fn get_all_opened(&self) -> Vec<Vec<u64>> {
self.opened.iter().cloned().collect()
}
#[must_use]
pub const fn opened(&self) -> &HashSet<Vec<u64>> {
&self.opened
}
#[must_use]
pub fn selected(&self) -> &[u64] {
&self.selected
}
/// Get a flat list of all currently viewable (including by scrolling) [`TreeItem`]s with this `TreeState`.
#[must_use]
pub fn flatten<'a, T>(&self, items: &'a [TreeItem<T>]) -> Vec<Flattened<'a, T>>
where
T: ToText + Clone + Default + Display + Hash + PartialEq + Eq,
{
flatten(&self.opened, items, &[])
}
/// Selects the given identifier.
///
/// Returns `true` when the selection changed.
///
/// Clear the selection by passing an empty identifier vector:
///
/// ```rust
/// # use managarr_tree_widget::TreeState;
/// # let mut state = TreeState::default();
/// state.select(Vec::new());
/// ```
pub fn select(&mut self, identifier: Vec<u64>) -> bool {
self.ensure_selected_in_view_on_next_render = true;
let changed = self.selected != identifier;
self.selected = identifier;
changed
}
/// Open a tree node.
/// Returns `true` when it was closed and has been opened.
/// Returns `false` when it was already open.
pub fn open(&mut self, identifier: Vec<u64>) -> bool {
if identifier.is_empty() {
false
} else {
self.opened.insert(identifier)
}
}
/// Close a tree node.
/// Returns `true` when it was open and has been closed.
/// Returns `false` when it was already closed.
pub fn close(&mut self, identifier: &[u64]) -> bool {
self.opened.remove(identifier)
}
/// Toggles a tree node open/close state.
/// When it is currently open, then [`close`](Self::close) is called. Otherwise [`open`](Self::open).
///
/// Returns `true` when a node is opened / closed.
/// As toggle always changes something, this only returns `false` when an empty identifier is given.
pub fn toggle(&mut self, identifier: Vec<u64>) -> bool {
if identifier.is_empty() {
false
} else if self.opened.contains(&identifier) {
self.close(&identifier)
} else {
self.open(identifier)
}
}
/// Toggles the currently selected tree node open/close state.
/// See also [`toggle`](Self::toggle)
///
/// Returns `true` when a node is opened / closed.
/// As toggle always changes something, this only returns `false` when nothing is selected.
pub fn toggle_selected(&mut self) -> bool {
if self.selected.is_empty() {
return false;
}
self.ensure_selected_in_view_on_next_render = true;
// Reimplement self.close because of multiple different borrows
let was_open = self.opened.remove(&self.selected);
if was_open {
return true;
}
self.open(self.selected.clone())
}
/// Closes all open nodes.
///
/// Returns `true` when any node was closed.
pub fn close_all(&mut self) -> bool {
if self.opened.is_empty() {
false
} else {
self.opened.clear();
true
}
}
/// Select the first node.
///
/// Returns `true` when the selection changed.
pub fn select_first(&mut self) -> bool {
let identifier = self.last_identifiers.first().cloned().unwrap_or_default();
self.select(identifier)
}
/// Select the last node.
///
/// Returns `true` when the selection changed.
pub fn select_last(&mut self) -> bool {
let new_identifier = self.last_identifiers.last().cloned().unwrap_or_default();
self.select(new_identifier)
}
/// Select the node on the given index.
///
/// Returns `true` when the selection changed.
///
/// This can be useful for mouse clicks.
#[deprecated = "Prefer self.click_at or self.rendered_at as visible index is hard to predict with height != 1"]
pub fn select_visible_index(&mut self, new_index: usize) -> bool {
let new_index = new_index.min(self.last_biggest_index);
let new_identifier = self
.last_identifiers
.get(new_index)
.cloned()
.unwrap_or_default();
self.select(new_identifier)
}
/// Move the current selection with the direction/amount by the given function.
///
/// Returns `true` when the selection changed.
///
/// # Example
///
/// ```
/// # use managarr_tree_widget::TreeState;
/// # let mut state = TreeState::default();
/// // Move the selection one down
/// state.select_relative(|current| {
/// // When nothing is currently selected, select index 0
/// // Otherwise select current + 1 (without panicking)
/// current.map_or(0, |current| current.saturating_add(1))
/// });
/// ```
///
/// For more examples take a look into the source code of [`key_up`](Self::key_up) or [`key_down`](Self::key_down).
/// They are implemented with this method.
#[deprecated = "renamed to select_relative"]
pub fn select_visible_relative<F>(&mut self, change_function: F) -> bool
where
F: FnOnce(Option<usize>) -> usize,
{
let identifiers = &self.last_identifiers;
let current_identifier = &self.selected;
let current_index = identifiers
.iter()
.position(|identifier| identifier == current_identifier);
let new_index = change_function(current_index).min(self.last_biggest_index);
let new_identifier = identifiers.get(new_index).cloned().unwrap_or_default();
self.select(new_identifier)
}
/// Move the current selection with the direction/amount by the given function.
///
/// Returns `true` when the selection changed.
///
/// # Example
///
/// ```
/// # use managarr_tree_widget::TreeState;
/// # let mut state = TreeState::default();
/// // Move the selection one down
/// state.select_relative(|current| {
/// // When nothing is currently selected, select index 0
/// // Otherwise select current + 1 (without panicking)
/// current.map_or(0, |current| current.saturating_add(1))
/// });
/// ```
///
/// For more examples take a look into the source code of [`key_up`](Self::key_up) or [`key_down`](Self::key_down).
/// They are implemented with this method.
pub fn select_relative<F>(&mut self, change_function: F) -> bool
where
F: FnOnce(Option<usize>) -> usize,
{
let identifiers = &self.last_identifiers;
let current_identifier = &self.selected;
let current_index = identifiers
.iter()
.position(|identifier| identifier == current_identifier);
let new_index = change_function(current_index).min(self.last_biggest_index);
let new_identifier = identifiers.get(new_index).cloned().unwrap_or_default();
self.select(new_identifier)
}
/// Get the identifier that was rendered for the given position on last render.
#[must_use]
pub fn rendered_at(&self, position: Position) -> Option<&[u64]> {
if !self.last_area.contains(position) {
return None;
}
self.last_rendered_identifiers
.iter()
.rev()
.find(|(y, _)| position.y >= *y)
.map(|(_, identifier)| identifier.as_ref())
}
/// Select what was rendered at the given position on last render.
/// When it is already selected, toggle it.
///
/// Returns `true` when the state changed.
/// Returns `false` when there was nothing at the given position.
pub fn click_at(&mut self, position: Position) -> bool {
if let Some(identifier) = self.rendered_at(position) {
if identifier == self.selected {
self.toggle_selected()
} else {
self.select(identifier.to_vec())
}
} else {
false
}
}
/// Ensure the selected [`TreeItem`] is in view on next render
pub fn scroll_selected_into_view(&mut self) {
self.ensure_selected_in_view_on_next_render = true;
}
/// Scroll the specified amount of lines up
///
/// Returns `true` when the scroll position changed.
/// Returns `false` when the scrolling has reached the top.
pub fn scroll_up(&mut self, lines: usize) -> bool {
let before = self.offset;
self.offset = self.offset.saturating_sub(lines);
before != self.offset
}
/// Scroll the specified amount of lines down
///
/// Returns `true` when the scroll position changed.
/// Returns `false` when the scrolling has reached the last [`TreeItem`].
pub fn scroll_down(&mut self, lines: usize) -> bool {
let before = self.offset;
self.offset = self
.offset
.saturating_add(lines)
.min(self.last_biggest_index);
before != self.offset
}
/// Handles the up arrow key.
/// Moves up in the current depth or to its parent.
///
/// Returns `true` when the selection changed.
pub fn key_up(&mut self) -> bool {
self.select_relative(|current| {
// When nothing is selected, fall back to end
current.map_or(usize::MAX, |current| current.saturating_sub(1))
})
}
/// Handles the down arrow key.
/// Moves down in the current depth or into a child node.
///
/// Returns `true` when the selection changed.
pub fn key_down(&mut self) -> bool {
self.select_relative(|current| {
// When nothing is selected, fall back to start
current.map_or(0, |current| current.saturating_add(1))
})
}
/// Handles the left arrow key.
/// Closes the currently selected or moves to its parent.
///
/// Returns `true` when the selection or the open state changed.
pub fn key_left(&mut self) -> bool {
self.ensure_selected_in_view_on_next_render = true;
// Reimplement self.close because of multiple different borrows
let mut changed = self.opened.remove(&self.selected);
if !changed {
// Select the parent by removing the leaf from selection
let popped = self.selected.pop();
changed = popped.is_some();
}
changed
}
/// Handles the right arrow key.
/// Opens the currently selected.
///
/// Returns `true` when it was closed and has been opened.
/// Returns `false` when it was already open or nothing being selected.
pub fn key_right(&mut self) -> bool {
if self.selected.is_empty() {
false
} else {
self.ensure_selected_in_view_on_next_render = true;
self.open(self.selected.clone())
}
}
}