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refactor: one struct per file

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This commit is contained in:
EdJoPaTo
2024-02-22 18:32:35 +01:00
parent 3cafeaef0a
commit 766d4f1d58
4 changed files with 412 additions and 412 deletions
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src/flatten.rs
+13 -16
View File
@@ -1,13 +1,13 @@
use std::collections::HashSet; use std::collections::HashSet;
use crate::TreeItem; use crate::item::Item;
/// A flattened item of all visible [`TreeItem`s](TreeItem). /// A flattened item of all visible [`TreeItem`s](Item).
/// ///
/// Generated via [`TreeState::flatten`](crate::TreeState::flatten). /// Generated via [`TreeState::flatten`](crate::TreeState::flatten).
pub struct Flattened<'a, Identifier> { pub struct Flattened<'a, Identifier> {
pub identifier: Vec<Identifier>, pub identifier: Vec<Identifier>,
pub item: &'a TreeItem<'a, Identifier>, pub item: &'a Item<'a, Identifier>,
} }
impl<'a, Identifier> Flattened<'a, Identifier> { impl<'a, Identifier> Flattened<'a, Identifier> {
@@ -21,7 +21,7 @@ impl<'a, Identifier> Flattened<'a, Identifier> {
#[must_use] #[must_use]
pub fn flatten<'a, Identifier>( pub fn flatten<'a, Identifier>(
opened: &HashSet<Vec<Identifier>>, opened: &HashSet<Vec<Identifier>>,
items: &'a [TreeItem<'a, Identifier>], items: &'a [Item<'a, Identifier>],
) -> Vec<Flattened<'a, Identifier>> ) -> Vec<Flattened<'a, Identifier>>
where where
Identifier: Clone + PartialEq + Eq + core::hash::Hash, Identifier: Clone + PartialEq + Eq + core::hash::Hash,
@@ -32,7 +32,7 @@ where
#[must_use] #[must_use]
fn internal<'a, Identifier>( fn internal<'a, Identifier>(
opened: &HashSet<Vec<Identifier>>, opened: &HashSet<Vec<Identifier>>,
items: &'a [TreeItem<'a, Identifier>], items: &'a [Item<'a, Identifier>],
current: &[Identifier], current: &[Identifier],
) -> Vec<Flattened<'a, Identifier>> ) -> Vec<Flattened<'a, Identifier>>
where where
@@ -57,28 +57,25 @@ where
} }
#[cfg(test)] #[cfg(test)]
fn get_example_tree_items() -> Vec<TreeItem<'static, &'static str>> { fn get_example_tree_items() -> Vec<Item<'static, &'static str>> {
vec![ vec![
TreeItem::new_leaf("a", "Alfa"), Item::new_leaf("a", "Alfa"),
TreeItem::new( Item::new(
"b", "b",
"Bravo", "Bravo",
vec![ vec![
TreeItem::new_leaf("c", "Charlie"), Item::new_leaf("c", "Charlie"),
TreeItem::new( Item::new(
"d", "d",
"Delta", "Delta",
vec![ vec![Item::new_leaf("e", "Echo"), Item::new_leaf("f", "Foxtrot")],
TreeItem::new_leaf("e", "Echo"),
TreeItem::new_leaf("f", "Foxtrot"),
],
) )
.expect("all item identifiers are unique"), .expect("all item identifiers are unique"),
TreeItem::new_leaf("g", "Golf"), Item::new_leaf("g", "Golf"),
], ],
) )
.expect("all item identifiers are unique"), .expect("all item identifiers are unique"),
TreeItem::new_leaf("h", "Hotel"), Item::new_leaf("h", "Hotel"),
] ]
} }
src/item.rs
+163
View File
@@ -0,0 +1,163 @@
use std::collections::HashSet;
use ratatui::style::Style;
use ratatui::text::Text;
/// One item inside a [`Tree`](crate::Tree).
///
/// Can have zero or more `children`.
///
/// # Identifier
///
/// The generic argument `Identifier` is used to keep the state like the currently selected or opened [`TreeItem`s](Item) in the [`TreeState`](crate::TreeState).
///
/// It needs to be unique among its siblings but can be used again on parent or child [`TreeItem`s](Item).
/// A common example would be a filename which has to be unique in its directory while it can exist in another.
///
/// The `text` can be different from its `identifier`.
/// To repeat the filename analogy: File browsers sometimes hide file extensions.
/// The filename `main.rs` is the identifier while its shown as `main`.
/// Two files `main.rs` and `main.toml` can exist in the same directory and can both be displayed as `main` but their identifier is different.
///
/// Just like every file in a file system can be uniquely identified with its file and directory names each [`TreeItem`](Item) in a [`Tree`](crate::Tree) can be with these identifiers.
/// As an example the following two identifiers describe the main file in a Rust cargo project: `vec!["src", "main.rs"]`.
///
/// The identifier does not need to be a `String` and is therefore generic.
/// Until version 0.14 this crate used `usize` and indices.
/// This might still be perfect for your use case.
///
/// # Example
///
/// ```
/// # use tui_tree_widget::TreeItem;
/// let a = TreeItem::new_leaf("l", "Leaf");
/// let b = TreeItem::new("r", "Root", vec![a])?;
/// # Ok::<(), std::io::Error>(())
/// ```
#[derive(Debug, Clone)]
pub struct Item<'a, Identifier> {
pub(super) identifier: Identifier,
pub(super) text: Text<'a>,
pub(super) style: Style,
pub(super) children: Vec<Item<'a, Identifier>>,
}
impl<'a, Identifier> Item<'a, Identifier>
where
Identifier: Clone + PartialEq + Eq + core::hash::Hash,
{
/// Create a new `TreeItem` without children.
#[must_use]
pub fn new_leaf<T>(identifier: Identifier, text: T) -> Self
where
T: Into<Text<'a>>,
{
Self {
identifier,
text: text.into(),
style: Style::new(),
children: Vec::new(),
}
}
/// Create a new `TreeItem` with children.
///
/// # Errors
///
/// Errors when there are duplicate identifiers in the children.
pub fn new<T>(
identifier: Identifier,
text: T,
children: Vec<Item<'a, Identifier>>,
) -> std::io::Result<Self>
where
T: Into<Text<'a>>,
{
let identifiers = children
.iter()
.map(|o| &o.identifier)
.collect::<HashSet<_>>();
if identifiers.len() != children.len() {
return Err(std::io::Error::new(
std::io::ErrorKind::AlreadyExists,
"The children contain duplicate identifiers",
));
}
Ok(Self {
identifier,
text: text.into(),
style: Style::new(),
children,
})
}
#[must_use]
pub fn children(&self) -> &[Item<Identifier>] {
&self.children
}
/// Get a reference to a child by index.
#[must_use]
pub fn child(&self, index: usize) -> Option<&Self> {
self.children.get(index)
}
/// Get a mutable reference to a child by index.
///
/// When you choose to change the `identifier` the [`TreeState`](crate::TreeState) might not work as expected afterwards.
#[must_use]
pub fn child_mut(&mut self, index: usize) -> Option<&mut Self> {
self.children.get_mut(index)
}
#[must_use]
pub fn height(&self) -> usize {
self.text.height()
}
#[must_use]
pub const fn style(mut self, style: Style) -> Self {
self.style = style;
self
}
/// Add a child to the `TreeItem`.
///
/// # Errors
///
/// Errors when the `identifier` of the `child` already exists in the children.
pub fn add_child(&mut self, child: Item<'a, Identifier>) -> std::io::Result<()> {
let existing = self
.children
.iter()
.map(|o| &o.identifier)
.collect::<HashSet<_>>();
if existing.contains(&child.identifier) {
return Err(std::io::Error::new(
std::io::ErrorKind::AlreadyExists,
"identifier already exists in the children",
));
}
self.children.push(child);
Ok(())
}
}
#[test]
#[should_panic = "duplicate identifiers"]
fn tree_item_new_errors_with_duplicate_identifiers() {
let a = Item::new_leaf("same", "text");
let b = a.clone();
Item::new("root", "Root", vec![a, b]).unwrap();
}
#[test]
#[should_panic = "identifier already exists"]
fn tree_item_add_child_errors_with_duplicate_identifiers() {
let a = Item::new_leaf("same", "text");
let b = a.clone();
let mut root = Item::new("root", "Root", vec![a]).unwrap();
root.add_child(b).unwrap();
}
src/lib.rs
+4 -396
View File
@@ -12,410 +12,18 @@ use std::collections::HashSet;
use ratatui::buffer::Buffer; use ratatui::buffer::Buffer;
use ratatui::layout::{Corner, Rect}; use ratatui::layout::{Corner, Rect};
use ratatui::style::Style; use ratatui::style::Style;
use ratatui::text::Text;
use ratatui::widgets::{Block, StatefulWidget, Widget}; use ratatui::widgets::{Block, StatefulWidget, Widget};
use unicode_width::UnicodeWidthStr; use unicode_width::UnicodeWidthStr;
mod flatten; mod flatten;
mod identifier; mod identifier;
mod item;
mod state;
use crate::flatten::flatten;
pub use crate::flatten::Flattened; pub use crate::flatten::Flattened;
pub use crate::identifier::get_without_leaf as get_identifier_without_leaf; pub use crate::identifier::get_without_leaf as get_identifier_without_leaf;
pub use crate::item::Item as TreeItem;
/// Keeps the state of what is currently selected and what was opened in a [`Tree`]. pub use crate::state::State as TreeState;
///
/// The generic argument `Identifier` is used to keep the state like the currently selected or opened [`TreeItem`s](TreeItem) in the [`TreeState`].
/// For more information see [`TreeItem`].
///
/// # Example
///
/// ```
/// # use tui_tree_widget::TreeState;
/// type Identifier = usize;
///
/// let mut state = TreeState::<Identifier>::default();
/// ```
#[derive(Debug, Default, Clone)]
pub struct TreeState<Identifier> {
offset: usize,
opened: HashSet<Vec<Identifier>>,
selected: Vec<Identifier>,
ensure_selected_in_view_on_next_render: bool,
}
impl<Identifier> TreeState<Identifier>
where
Identifier: Clone + PartialEq + Eq + core::hash::Hash,
{
#[must_use]
pub const fn get_offset(&self) -> usize {
self.offset
}
#[must_use]
pub fn get_all_opened(&self) -> Vec<Vec<Identifier>> {
self.opened.iter().cloned().collect()
}
/// Get a flat list of all visible [`TreeItem`s](TreeItem) with this `TreeState`.
#[must_use]
pub fn flatten<'a>(
&self,
items: &'a [TreeItem<'a, Identifier>],
) -> Vec<Flattened<'a, Identifier>> {
flatten(&self.opened, items)
}
#[must_use]
pub fn selected(&self) -> Vec<Identifier> {
self.selected.clone()
}
/// Selects the given identifier.
///
/// Returns `true` when the selection changed.
///
/// Clear the selection by passing an empty identifier vector:
///
/// ```rust
/// # use tui_tree_widget::TreeState;
/// # let mut state = TreeState::<usize>::default();
/// state.select(Vec::new());
/// ```
pub fn select(&mut self, identifier: Vec<Identifier>) -> bool {
let changed = self.selected != identifier;
self.selected = identifier;
self.ensure_selected_in_view_on_next_render = true;
changed
}
/// Open a tree node.
/// Returns `true` if the node was closed and has been opened.
/// Returns `false` if the node was already open.
pub fn open(&mut self, identifier: Vec<Identifier>) -> bool {
if identifier.is_empty() {
false
} else {
self.opened.insert(identifier)
}
}
/// Close a tree node.
/// Returns `true` if the node was open and has been closed.
/// Returns `false` if the node was already closed.
pub fn close(&mut self, identifier: &[Identifier]) -> bool {
self.opened.remove(identifier)
}
/// Toggles a tree node.
/// If the node is in opened then it calls `close()`. Otherwise it calls `open()`.
pub fn toggle(&mut self, identifier: Vec<Identifier>) {
if self.opened.contains(&identifier) {
self.close(&identifier);
} else {
self.open(identifier);
}
}
/// Toggles the currently selected tree node.
/// See also [`toggle`](TreeState::toggle)
pub fn toggle_selected(&mut self) {
self.toggle(self.selected());
self.ensure_selected_in_view_on_next_render = true;
}
pub fn close_all(&mut self) {
self.opened.clear();
}
/// Select the first node.
///
/// Returns `true` when the selection changed.
pub fn select_first(&mut self, items: &[TreeItem<Identifier>]) -> bool {
let identifier = items
.first()
.map(|o| vec![o.identifier.clone()])
.unwrap_or_default();
self.select(identifier)
}
/// Select the last visible node.
///
/// Returns `true` when the selection changed.
pub fn select_last(&mut self, items: &[TreeItem<Identifier>]) -> bool {
let visible = self.flatten(items);
let new_identifier = visible
.last()
.map(|o| o.identifier.clone())
.unwrap_or_default();
self.select(new_identifier)
}
/// Select the node visible on the given index.
///
/// Returns `true` when the selection changed.
///
/// This can be useful for mouse clicks.
pub fn select_visible_index(
&mut self,
items: &[TreeItem<Identifier>],
new_index: usize,
) -> bool {
let visible = self.flatten(items);
let new_index = new_index.min(visible.len().saturating_sub(1));
let new_identifier = visible
.get(new_index)
.map(|o| o.identifier.clone())
.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 tui_tree_widget::TreeState;
/// # let items = vec![];
/// # type Identifier = usize;
/// # let mut state = TreeState::<Identifier>::default();
/// // Move the selection one down
/// state.select_visible_relative(&items, |current| {
/// current.map_or(0, |current| current.saturating_add(1))
/// });
/// ```
///
/// For more examples take a look into the source code of [`TreeState::key_up`] or [`TreeState::key_down`].
/// They are implemented with this method.
pub fn select_visible_relative<F>(&mut self, items: &[TreeItem<Identifier>], f: F) -> bool
where
F: FnOnce(Option<usize>) -> usize,
{
let visible = self.flatten(items);
let current_identifier = self.selected();
let current_index = visible
.iter()
.position(|o| o.identifier == current_identifier);
let new_index = f(current_index).min(visible.len().saturating_sub(1));
let new_identifier = visible
.get(new_index)
.map(|o| o.identifier.clone())
.unwrap_or_default();
self.select(new_identifier)
}
/// Ensure the selected [`TreeItem`] is visible 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
pub fn scroll_up(&mut self, lines: usize) {
self.offset = self.offset.saturating_sub(lines);
}
/// Scroll the specified amount of lines down
pub fn scroll_down(&mut self, lines: usize) {
self.offset = self.offset.saturating_add(lines);
}
/// Handles the up arrow key.
/// Moves up in the current depth or to its parent.
pub fn key_up(&mut self, items: &[TreeItem<Identifier>]) {
self.select_visible_relative(items, |current| {
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.
pub fn key_down(&mut self, items: &[TreeItem<Identifier>]) {
self.select_visible_relative(items, |current| {
current.map_or(0, |current| current.saturating_add(1))
});
}
/// Handles the left arrow key.
/// Closes the currently selected or moves to its parent.
pub fn key_left(&mut self) {
// Reimplement self.close because of multiple different borrows
let changed = self.opened.remove(&self.selected);
if !changed {
// Select the parent by removing the leaf from selection
self.selected.pop();
}
self.ensure_selected_in_view_on_next_render = true;
}
/// Handles the right arrow key.
/// Opens the currently selected.
pub fn key_right(&mut self) {
self.open(self.selected());
self.ensure_selected_in_view_on_next_render = true;
}
}
/// One item inside a [`Tree`].
///
/// Can have zero or more `children`.
///
/// # Identifier
///
/// The generic argument `Identifier` is used to keep the state like the currently selected or opened [`TreeItem`s](TreeItem) in the [`TreeState`].
///
/// It needs to be unique among its siblings but can be used again on parent or child [`TreeItem`s](TreeItem).
/// A common example would be a filename which has to be unique in its directory while it can exist in another.
///
/// The `text` can be different from its `identifier`.
/// To repeat the filename analogy: File browsers sometimes hide file extensions.
/// The filename `main.rs` is the identifier while its shown as `main`.
/// Two files `main.rs` and `main.toml` can exist in the same directory and can both be displayed as `main` but their identifier is different.
///
/// Just like every file in a file system can be uniquely identified with its file and directory names each [`TreeItem`] in a [`Tree`] can be with these identifiers.
/// As an example the following two identifiers describe the main file in a Rust cargo project: `vec!["src", "main.rs"]`.
///
/// The identifier does not need to be a `String` and is therefore generic.
/// Until version 0.14 this crate used `usize` and indices.
/// This might still be perfect for your use case.
///
/// # Example
///
/// ```
/// # use tui_tree_widget::TreeItem;
/// let a = TreeItem::new_leaf("l", "Leaf");
/// let b = TreeItem::new("r", "Root", vec![a])?;
/// # Ok::<(), std::io::Error>(())
/// ```
#[derive(Debug, Clone)]
pub struct TreeItem<'a, Identifier> {
identifier: Identifier,
text: Text<'a>,
style: Style,
children: Vec<TreeItem<'a, Identifier>>,
}
impl<'a, Identifier> TreeItem<'a, Identifier>
where
Identifier: Clone + PartialEq + Eq + core::hash::Hash,
{
/// Create a new `TreeItem` without children.
#[must_use]
pub fn new_leaf<T>(identifier: Identifier, text: T) -> Self
where
T: Into<Text<'a>>,
{
Self {
identifier,
text: text.into(),
style: Style::new(),
children: Vec::new(),
}
}
/// Create a new `TreeItem` with children.
///
/// # Errors
///
/// Errors when there are duplicate identifiers in the children.
pub fn new<T>(
identifier: Identifier,
text: T,
children: Vec<TreeItem<'a, Identifier>>,
) -> std::io::Result<Self>
where
T: Into<Text<'a>>,
{
let identifiers = children
.iter()
.map(|o| &o.identifier)
.collect::<HashSet<_>>();
if identifiers.len() != children.len() {
return Err(std::io::Error::new(
std::io::ErrorKind::AlreadyExists,
"The children contain duplicate identifiers",
));
}
Ok(Self {
identifier,
text: text.into(),
style: Style::new(),
children,
})
}
#[must_use]
pub fn children(&self) -> &[TreeItem<Identifier>] {
&self.children
}
/// Get a reference to a child by index.
#[must_use]
pub fn child(&self, index: usize) -> Option<&Self> {
self.children.get(index)
}
/// Get a mutable reference to a child by index.
///
/// When you choose to change the `identifier` the [`TreeState`] might not work as expected afterwards.
#[must_use]
pub fn child_mut(&mut self, index: usize) -> Option<&mut Self> {
self.children.get_mut(index)
}
#[must_use]
pub fn height(&self) -> usize {
self.text.height()
}
#[must_use]
pub const fn style(mut self, style: Style) -> Self {
self.style = style;
self
}
/// Add a child to the `TreeItem`.
///
/// # Errors
///
/// Errors when the `identifier` of the `child` already exists in the children.
pub fn add_child(&mut self, child: TreeItem<'a, Identifier>) -> std::io::Result<()> {
let existing = self
.children
.iter()
.map(|o| &o.identifier)
.collect::<HashSet<_>>();
if existing.contains(&child.identifier) {
return Err(std::io::Error::new(
std::io::ErrorKind::AlreadyExists,
"identifier already exists in the children",
));
}
self.children.push(child);
Ok(())
}
}
#[test]
#[should_panic = "duplicate identifiers"]
fn tree_item_new_errors_with_duplicate_identifiers() {
let a = TreeItem::new_leaf("same", "text");
let b = a.clone();
TreeItem::new("root", "Root", vec![a, b]).unwrap();
}
#[test]
#[should_panic = "identifier already exists"]
fn tree_item_add_child_errors_with_duplicate_identifiers() {
let a = TreeItem::new_leaf("same", "text");
let b = a.clone();
let mut root = TreeItem::new("root", "Root", vec![a]).unwrap();
root.add_child(b).unwrap();
}
/// A `Tree` which can be rendered. /// A `Tree` which can be rendered.
/// ///
src/state.rs
+232
View File
@@ -0,0 +1,232 @@
use std::collections::HashSet;
use crate::flatten::{flatten, Flattened};
use crate::item::Item;
/// Keeps the state of what is currently selected and what was opened in a [`Tree`](crate::Tree).
///
/// The generic argument `Identifier` is used to keep the state like the currently selected or opened [`TreeItem`s](Item) in the [`TreeState`](State).
/// For more information see [`TreeItem`](Item).
///
/// # Example
///
/// ```
/// # use tui_tree_widget::TreeState;
/// type Identifier = usize;
///
/// let mut state = TreeState::<Identifier>::default();
/// ```
#[derive(Debug, Default, Clone)]
pub struct State<Identifier> {
pub(super) offset: usize,
pub(super) opened: HashSet<Vec<Identifier>>,
pub(super) selected: Vec<Identifier>,
pub(super) ensure_selected_in_view_on_next_render: bool,
}
impl<Identifier> State<Identifier>
where
Identifier: Clone + PartialEq + Eq + core::hash::Hash,
{
#[must_use]
pub const fn get_offset(&self) -> usize {
self.offset
}
#[must_use]
pub fn get_all_opened(&self) -> Vec<Vec<Identifier>> {
self.opened.iter().cloned().collect()
}
/// Get a flat list of all visible (= below open) [`TreeItem`s](Item) with this `TreeState`.
#[must_use]
pub fn flatten<'a>(&self, items: &'a [Item<'a, Identifier>]) -> Vec<Flattened<'a, Identifier>> {
flatten(&self.opened, items)
}
#[must_use]
pub fn selected(&self) -> Vec<Identifier> {
self.selected.clone()
}
/// Selects the given identifier.
///
/// Returns `true` when the selection changed.
///
/// Clear the selection by passing an empty identifier vector:
///
/// ```rust
/// # use tui_tree_widget::TreeState;
/// # let mut state = TreeState::<usize>::default();
/// state.select(Vec::new());
/// ```
pub fn select(&mut self, identifier: Vec<Identifier>) -> bool {
let changed = self.selected != identifier;
self.selected = identifier;
self.ensure_selected_in_view_on_next_render = true;
changed
}
/// Open a tree node.
/// Returns `true` if the node was closed and has been opened.
/// Returns `false` if the node was already open.
pub fn open(&mut self, identifier: Vec<Identifier>) -> bool {
if identifier.is_empty() {
false
} else {
self.opened.insert(identifier)
}
}
/// Close a tree node.
/// Returns `true` if the node was open and has been closed.
/// Returns `false` if the node was already closed.
pub fn close(&mut self, identifier: &[Identifier]) -> bool {
self.opened.remove(identifier)
}
/// Toggles a tree node.
/// If the node is in opened then it calls [`close`](State::close). Otherwise it calls [`open`](State::open).
pub fn toggle(&mut self, identifier: Vec<Identifier>) {
if self.opened.contains(&identifier) {
self.close(&identifier);
} else {
self.open(identifier);
}
}
/// Toggles the currently selected tree node.
/// See also [`toggle`](State::toggle)
pub fn toggle_selected(&mut self) {
self.toggle(self.selected());
self.ensure_selected_in_view_on_next_render = true;
}
pub fn close_all(&mut self) {
self.opened.clear();
}
/// Select the first node.
///
/// Returns `true` when the selection changed.
pub fn select_first(&mut self, items: &[Item<Identifier>]) -> bool {
let identifier = items
.first()
.map(|o| vec![o.identifier.clone()])
.unwrap_or_default();
self.select(identifier)
}
/// Select the last visible node.
///
/// Returns `true` when the selection changed.
pub fn select_last(&mut self, items: &[Item<Identifier>]) -> bool {
let visible = self.flatten(items);
let new_identifier = visible
.last()
.map(|o| o.identifier.clone())
.unwrap_or_default();
self.select(new_identifier)
}
/// Select the node visible on the given index.
///
/// Returns `true` when the selection changed.
///
/// This can be useful for mouse clicks.
pub fn select_visible_index(&mut self, items: &[Item<Identifier>], new_index: usize) -> bool {
let visible = self.flatten(items);
let new_index = new_index.min(visible.len().saturating_sub(1));
let new_identifier = visible
.get(new_index)
.map(|o| o.identifier.clone())
.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 tui_tree_widget::TreeState;
/// # let items = vec![];
/// # type Identifier = usize;
/// # let mut state = TreeState::<Identifier>::default();
/// // Move the selection one down
/// state.select_visible_relative(&items, |current| {
/// current.map_or(0, |current| current.saturating_add(1))
/// });
/// ```
///
/// For more examples take a look into the source code of [`key_up`](State::key_up) or [`key_down`](State::key_down).
/// They are implemented with this method.
pub fn select_visible_relative<F>(&mut self, items: &[Item<Identifier>], f: F) -> bool
where
F: FnOnce(Option<usize>) -> usize,
{
let visible = self.flatten(items);
let current_identifier = self.selected();
let current_index = visible
.iter()
.position(|o| o.identifier == current_identifier);
let new_index = f(current_index).min(visible.len().saturating_sub(1));
let new_identifier = visible
.get(new_index)
.map(|o| o.identifier.clone())
.unwrap_or_default();
self.select(new_identifier)
}
/// Ensure the selected [`TreeItem`](Item) is visible 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
pub fn scroll_up(&mut self, lines: usize) {
self.offset = self.offset.saturating_sub(lines);
}
/// Scroll the specified amount of lines down
pub fn scroll_down(&mut self, lines: usize) {
self.offset = self.offset.saturating_add(lines);
}
/// Handles the up arrow key.
/// Moves up in the current depth or to its parent.
pub fn key_up(&mut self, items: &[Item<Identifier>]) {
self.select_visible_relative(items, |current| {
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.
pub fn key_down(&mut self, items: &[Item<Identifier>]) {
self.select_visible_relative(items, |current| {
current.map_or(0, |current| current.saturating_add(1))
});
}
/// Handles the left arrow key.
/// Closes the currently selected or moves to its parent.
pub fn key_left(&mut self) {
// Reimplement self.close because of multiple different borrows
let changed = self.opened.remove(&self.selected);
if !changed {
// Select the parent by removing the leaf from selection
self.selected.pop();
}
self.ensure_selected_in_view_on_next_render = true;
}
/// Handles the right arrow key.
/// Opens the currently selected.
pub fn key_right(&mut self) {
self.open(self.selected());
self.ensure_selected_in_view_on_next_render = true;
}
}