use crate::element::{BoxElement, Element, FlexDirection, TextElement};
use crate::event::{KeyEvent, MouseButton, MouseEvent, MouseEventKind};
use crate::interaction::{Activatable, Scrollable, Selectable};
use crate::style::{fit_visible, truncate_visible, visible_len, Color, Style};
use crate::theme::{Theme, ThemeRole};
use crossterm::event::KeyCode;
const MAX_TREE_PICKER_DEPTH_INDENT: usize = u16::MAX as usize;
const MAX_TREE_PICKER_DEPTH_WIDTH: usize = u16::MAX as usize;
const MAX_TREE_PICKER_INDENT: usize = u16::MAX as usize;
const MAX_TREE_PICKER_ITEM_DEPTH: usize = u16::MAX as usize;
const MAX_TREE_PICKER_ITEMS: usize = u16::MAX as usize;
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum TreePickerItemKind {
Branch { open: bool },
Leaf,
}
#[derive(Debug, Clone, PartialEq, Eq)]
pub struct TreePickerItem {
label: String,
description: Option<String>,
depth: usize,
kind: TreePickerItemKind,
color: Option<Color>,
disabled: bool,
}
impl TreePickerItem {
pub fn branch(label: impl Into<String>) -> Self {
Self {
label: label.into(),
description: None,
depth: 0,
kind: TreePickerItemKind::Branch { open: false },
color: None,
disabled: false,
}
}
pub fn leaf(label: impl Into<String>) -> Self {
Self {
label: label.into(),
description: None,
depth: 0,
kind: TreePickerItemKind::Leaf,
color: None,
disabled: false,
}
}
pub fn description(mut self, description: impl Into<String>) -> Self {
self.description = Some(description.into());
self
}
pub fn depth(mut self, depth: usize) -> Self {
self.depth = depth.min(MAX_TREE_PICKER_ITEM_DEPTH);
self
}
pub fn open(mut self, open: bool) -> Self {
if matches!(self.kind, TreePickerItemKind::Branch { .. }) {
self.kind = TreePickerItemKind::Branch { open };
}
self
}
pub fn color(mut self, color: Color) -> Self {
self.color = Some(color);
self
}
pub fn disabled(mut self, disabled: bool) -> Self {
self.disabled = disabled;
self
}
pub fn label(&self) -> &str {
&self.label
}
pub fn description_value(&self) -> Option<&str> {
self.description.as_deref()
}
pub fn depth_value(&self) -> usize {
self.depth
}
pub fn kind_value(&self) -> TreePickerItemKind {
self.kind
}
pub fn is_branch(&self) -> bool {
matches!(self.kind, TreePickerItemKind::Branch { .. })
}
pub fn is_open(&self) -> bool {
matches!(self.kind, TreePickerItemKind::Branch { open: true })
}
pub fn is_disabled(&self) -> bool {
self.disabled
}
}
#[derive(Debug, Clone, PartialEq, Eq)]
pub enum TreePickerMsg {
Selected(usize),
Toggled(usize),
Opened(usize),
Closed(usize),
Cancelled,
}
#[derive(Debug, Clone)]
pub struct TreePicker {
title: Option<String>,
subtitle: Option<String>,
items: Vec<TreePickerItem>,
selected: usize,
scroll: usize,
max_items: Option<usize>,
show_scroll: bool,
fill_height: bool,
y_offset: u16,
indent: usize,
depth_indent: usize,
open_marker: String,
closed_marker: String,
leaf_marker: String,
title_color: Color,
subtitle_color: Color,
branch_color: Color,
leaf_color: Color,
muted_color: Color,
selected_fg: Color,
selected_bg: Color,
disabled_color: Color,
footer: Option<String>,
}
impl TreePicker {
pub fn new(title: impl Into<String>) -> Self {
Self {
title: Some(title.into()),
subtitle: None,
items: Vec::new(),
selected: 0,
scroll: 0,
max_items: None,
show_scroll: true,
fill_height: false,
y_offset: 0,
indent: 2,
depth_indent: 2,
open_marker: "▾".to_string(),
closed_marker: "▸".to_string(),
leaf_marker: " ".to_string(),
title_color: Color::Cyan,
subtitle_color: Color::BrightBlack,
branch_color: Color::Cyan,
leaf_color: Color::White,
muted_color: Color::BrightBlack,
selected_fg: Color::BrightWhite,
selected_bg: Color::Cyan,
disabled_color: Color::BrightBlack,
footer: None,
}
}
pub fn without_title() -> Self {
Self {
title: None,
..Self::new("")
}
}
pub fn subtitle(mut self, subtitle: impl Into<String>) -> Self {
self.subtitle = Some(subtitle.into());
self
}
pub fn item(mut self, item: TreePickerItem) -> Self {
self.items.push(item);
self.clamp_selection();
self
}
pub fn items(mut self, items: Vec<TreePickerItem>) -> Self {
self.items = items;
self.clamp_selection();
self
}
pub fn add_item(&mut self, item: TreePickerItem) {
self.items.push(item);
self.clamp_selection();
}
pub fn selected(mut self, selected: usize) -> Self {
self.selected = selected;
self.clamp_selection();
self
}
pub fn scroll(mut self, scroll: usize) -> Self {
self.scroll = scroll;
self
}
pub fn max_items(mut self, max_items: usize) -> Self {
self.max_items = Some(max_items.clamp(1, MAX_TREE_PICKER_ITEMS));
self
}
pub fn show_scroll(mut self, enabled: bool) -> Self {
self.show_scroll = enabled;
self
}
pub fn fill_height(mut self, enabled: bool) -> Self {
self.fill_height = enabled;
self
}
pub fn footer(mut self, footer: impl Into<String>) -> Self {
self.footer = Some(footer.into());
self
}
pub fn indent(mut self, indent: usize) -> Self {
self.indent = indent.min(MAX_TREE_PICKER_INDENT);
self
}
pub fn depth_indent(mut self, indent: usize) -> Self {
self.depth_indent = indent.clamp(1, MAX_TREE_PICKER_DEPTH_INDENT);
self
}
pub fn markers(
mut self,
open: impl Into<String>,
closed: impl Into<String>,
leaf: impl Into<String>,
) -> Self {
let open = open.into();
let closed = closed.into();
let leaf = leaf.into();
if !open.is_empty() {
self.open_marker = open;
}
if !closed.is_empty() {
self.closed_marker = closed;
}
if !leaf.is_empty() {
self.leaf_marker = leaf;
}
self
}
pub fn title_color(mut self, color: Color) -> Self {
self.title_color = color;
self
}
pub fn subtitle_color(mut self, color: Color) -> Self {
self.subtitle_color = color;
self
}
pub fn branch_color(mut self, color: Color) -> Self {
self.branch_color = color;
self
}
pub fn leaf_color(mut self, color: Color) -> Self {
self.leaf_color = color;
self
}
pub fn muted_color(mut self, color: Color) -> Self {
self.muted_color = color;
self
}
pub fn selected_colors(mut self, fg: Color, bg: Color) -> Self {
self.selected_fg = fg;
self.selected_bg = bg;
self
}
pub fn disabled_color(mut self, color: Color) -> Self {
self.disabled_color = color;
self
}
pub fn with_theme(mut self, theme: &Theme) -> Self {
self.title_color = theme.color(ThemeRole::Primary);
self.subtitle_color = theme.color(ThemeRole::Muted);
self.branch_color = theme.color(ThemeRole::Primary);
self.leaf_color = theme.color(ThemeRole::Foreground);
self.muted_color = theme.color(ThemeRole::Muted);
self.selected_fg = theme.color(ThemeRole::Foreground);
self.selected_bg = theme.color(ThemeRole::Highlight);
self.disabled_color = theme.color(ThemeRole::Muted);
self
}
pub fn set_y_offset(&mut self, y: u16) {
self.y_offset = y;
}
pub fn items_value(&self) -> &[TreePickerItem] {
&self.items
}
pub fn selected_index(&self) -> usize {
self.normalized_selected()
}
pub fn selected_item(&self) -> Option<&TreePickerItem> {
self.items.get(self.normalized_selected())
}
pub fn handle_key(&mut self, key: &KeyEvent) -> Option<TreePickerMsg> {
match key.code {
KeyCode::Up | KeyCode::Char('k') => {
self.selected = self.normalized_selected().saturating_sub(1);
self.keep_selected_visible(1);
None
}
KeyCode::Down | KeyCode::Char('j') | KeyCode::Tab => {
let selected = self.normalized_selected();
if selected.saturating_add(1) < self.items.len() {
self.selected = selected + 1;
} else {
self.selected = selected;
}
self.keep_selected_visible(1);
None
}
KeyCode::PageUp => {
let step = self.max_items.unwrap_or(10);
self.selected = self.normalized_selected().saturating_sub(step);
self.keep_selected_visible(step);
None
}
KeyCode::PageDown => {
let step = self.max_items.unwrap_or(10);
self.selected = self
.normalized_selected()
.saturating_add(step)
.min(self.items.len().saturating_sub(1));
self.keep_selected_visible(step);
None
}
KeyCode::Home => {
self.selected = 0;
self.scroll = 0;
None
}
KeyCode::End => {
self.selected = self.items.len().saturating_sub(1);
self.keep_selected_visible(self.max_items.unwrap_or(10));
None
}
KeyCode::Right => self.branch_msg(TreePickerMsg::Opened, false),
KeyCode::Left => self.branch_msg(TreePickerMsg::Closed, true),
KeyCode::Enter => self.activate_selected(),
KeyCode::Esc => Some(TreePickerMsg::Cancelled),
_ => None,
}
}
pub fn handle_mouse(&mut self, mouse: &MouseEvent) -> Option<TreePickerMsg> {
match mouse.kind {
MouseEventKind::ScrollUp => {
super::relative_mouse_row(mouse.row, self.y_offset)?;
self.selected = self.normalized_selected().saturating_sub(1);
self.keep_selected_visible(1);
None
}
MouseEventKind::ScrollDown => {
super::relative_mouse_row(mouse.row, self.y_offset)?;
let selected = self.normalized_selected();
self.selected = selected
.saturating_add(1)
.min(self.items.len().saturating_sub(1));
self.keep_selected_visible(1);
None
}
MouseEventKind::Down(MouseButton::Left) => {
let local_row = super::relative_mouse_row(mouse.row, self.y_offset)?;
let item_row = local_row.checked_sub(self.item_start_row())?;
let item_count = self.visible_item_count_for_height(usize::MAX);
if item_row >= item_count {
return None;
}
let index = self.window_start(item_count).saturating_add(item_row);
if index < self.items.len() {
self.selected = index;
self.activate_selected()
} else {
None
}
}
_ => None,
}
}
pub fn view(&self, width: u16, height: usize) -> String {
let width = width as usize;
if width == 0 || height == 0 {
return String::new();
}
let mut lines = self.render_lines(width, height);
lines.truncate(height);
if self.fill_height {
while lines.len() < height {
lines.push(String::new());
}
}
lines
.into_iter()
.map(|line| fit_visible(&line, width))
.collect::<Vec<_>>()
.join("\n")
}
pub fn element<Msg>(&self) -> Element<Msg> {
let mut children = Vec::new();
if let Some(title) = self.title.as_deref().filter(|title| !title.is_empty()) {
children.push(Element::Text(
TextElement::new(title).fg(self.title_color).bold(),
));
}
if let Some(subtitle) = self
.subtitle
.as_deref()
.filter(|subtitle| !subtitle.is_empty())
{
children.push(Element::Text(
TextElement::new(subtitle).fg(self.subtitle_color),
));
}
let selected = self.normalized_selected();
for index in self.element_item_range() {
children.push(Element::Text(self.item_text_element(index, selected)));
}
if let Some(footer) = self.footer.as_deref().filter(|footer| !footer.is_empty()) {
children.push(Element::Text(TextElement::new(footer).fg(self.muted_color)));
}
Element::Box(
BoxElement::new()
.direction(FlexDirection::Column)
.children(children),
)
}
pub fn element_with_height<Msg>(&self, height: usize) -> Element<Msg> {
let mut children = Vec::new();
if let Some(title) = self.title.as_deref().filter(|title| !title.is_empty()) {
children.push(Element::Text(
TextElement::new(title).fg(self.title_color).bold(),
));
}
if let Some(subtitle) = self
.subtitle
.as_deref()
.filter(|subtitle| !subtitle.is_empty())
{
children.push(Element::Text(
TextElement::new(subtitle).fg(self.subtitle_color),
));
}
let visible_items = self.visible_item_count_for_height(height);
let start = self.window_start(visible_items);
let end = start.saturating_add(visible_items).min(self.items.len());
let selected = self.normalized_selected();
for index in start..end {
children.push(Element::Text(self.item_text_element(index, selected)));
}
if self.show_scroll && self.items.len() > visible_items && visible_items > 0 {
children.push(Element::Text(self.scroll_footer_element(start, end)));
}
if let Some(footer) = self.footer.as_deref().filter(|footer| !footer.is_empty()) {
children.push(Element::Text(TextElement::new(footer).fg(self.muted_color)));
}
children.truncate(height);
if self.fill_height {
while children.len() < height {
children.push(Element::Text(TextElement::new("")));
}
}
Element::Box(
BoxElement::new()
.direction(FlexDirection::Column)
.children(children),
)
}
fn render_lines(&self, width: usize, height: usize) -> Vec<String> {
let mut lines = Vec::new();
if let Some(title) = self.title.as_deref().filter(|title| !title.is_empty()) {
lines.push(
Style::new()
.fg(self.title_color)
.bold()
.render(&fit_visible(
&format!("{}{}", " ".repeat(self.indent_for_width(width)), title),
width,
)),
);
}
if let Some(subtitle) = self
.subtitle
.as_deref()
.filter(|subtitle| !subtitle.is_empty())
{
lines.push(Style::new().fg(self.subtitle_color).render(&fit_visible(
&format!("{}{}", " ".repeat(self.indent_for_width(width)), subtitle),
width,
)));
}
let visible_items = self.visible_item_count_for_height(height);
let start = self.window_start(visible_items);
let end = (start + visible_items).min(self.items.len());
for index in start..end {
lines.push(self.render_item(index, width));
}
if self.show_scroll && self.items.len() > visible_items && visible_items > 0 {
lines.push(self.render_scroll_footer(start, end, width));
}
if let Some(footer) = self.footer.as_deref().filter(|footer| !footer.is_empty()) {
lines.push(Style::new().fg(self.muted_color).render(&fit_visible(
&format!("{}{}", " ".repeat(self.indent_for_width(width)), footer),
width,
)));
}
lines
}
fn item_text_element(&self, index: usize, selected: usize) -> TextElement {
let item = &self.items[index];
let mut text = TextElement::new(self.plain_item_line(index, None));
if index == selected {
text = text.fg(self.selected_fg).bg(self.selected_bg).bold();
} else if item.disabled {
text = text.fg(self.disabled_color);
} else {
text = text.fg(item.color.unwrap_or(self.default_item_color(item)));
}
text
}
fn render_item(&self, index: usize, width: usize) -> String {
let raw = fit_visible(&self.plain_item_line(index, Some(width)), width);
let item = &self.items[index];
if index == self.normalized_selected() {
Style::new()
.fg(self.selected_fg)
.bg(self.selected_bg)
.render(&raw)
} else if item.disabled {
Style::new().fg(self.disabled_color).render(&raw)
} else {
Style::new()
.fg(item.color.unwrap_or(self.default_item_color(item)))
.render(&raw)
}
}
fn plain_item_line(&self, index: usize, width: Option<usize>) -> String {
let Some(item) = self.items.get(index) else {
return String::new();
};
let prefix = match width {
Some(width) => self.item_prefix_for_width(item, width),
None => self.item_prefix_for_element(item),
};
let mut label = item.label.clone();
if let Some(description) = item
.description
.as_deref()
.filter(|description| !description.is_empty())
{
label.push_str(" ");
label.push_str(description);
}
let available = width
.map(|width| width.saturating_sub(visible_len(&prefix)))
.unwrap_or(usize::MAX);
format!("{prefix}{}", truncate_visible(&label, available))
}
fn render_scroll_footer(&self, start: usize, end: usize, width: usize) -> String {
let up = if start > 0 { "↑" } else { " " };
let down = if end < self.items.len() { "↓" } else { " " };
Style::new().fg(self.muted_color).render(&fit_visible(
&format!(
"{}{up}{down} {}/{}",
" ".repeat(self.indent_for_width(width)),
self.normalized_selected()
.saturating_add(1)
.min(self.items.len()),
self.items.len()
),
width,
))
}
fn scroll_footer_element(&self, start: usize, end: usize) -> TextElement {
let up = if start > 0 { "↑" } else { " " };
let down = if end < self.items.len() { "↓" } else { " " };
TextElement::new(format!(
"{}{up}{down} {}/{}",
" ".repeat(self.indent_for_element()),
self.normalized_selected()
.saturating_add(1)
.min(self.items.len()),
self.items.len()
))
.fg(self.muted_color)
}
fn visible_item_count_for_height(&self, height: usize) -> usize {
if self.items.is_empty() {
return 0;
}
let reserved = self.item_start_row()
+ usize::from(
self.footer
.as_ref()
.is_some_and(|footer| !footer.is_empty()),
)
+ usize::from(self.show_scroll && self.items.len() > 1);
let available = height.saturating_sub(reserved).max(1);
self.max_items.unwrap_or(available).min(available)
}
fn window_start(&self, visible_items: usize) -> usize {
if visible_items == 0 || self.items.len() <= visible_items {
return 0;
}
let max_start = self.items.len().saturating_sub(visible_items);
let mut start = self.scroll.min(max_start);
let selected = self.normalized_selected();
if selected < start {
start = selected;
} else if selected >= start + visible_items {
start = selected + 1 - visible_items;
}
start.min(max_start)
}
fn element_item_range(&self) -> std::ops::Range<usize> {
let visible_items = self
.max_items
.unwrap_or(self.items.len())
.min(self.items.len());
let start = self.window_start(visible_items);
let end = start.saturating_add(visible_items).min(self.items.len());
start..end
}
fn keep_selected_visible(&mut self, window_hint: usize) {
let visible_items = self.max_items.unwrap_or(window_hint.max(1));
self.scroll = self.window_start(visible_items);
}
fn activate_selected(&self) -> Option<TreePickerMsg> {
let selected = self.normalized_selected();
let item = self.items.get(selected)?;
if item.disabled {
return None;
}
if item.is_branch() {
Some(TreePickerMsg::Toggled(selected))
} else {
Some(TreePickerMsg::Selected(selected))
}
}
fn branch_msg(
&self,
f: impl FnOnce(usize) -> TreePickerMsg,
expected_open: bool,
) -> Option<TreePickerMsg> {
let selected = self.normalized_selected();
let item = self.items.get(selected)?;
if item.disabled || !item.is_branch() || item.is_open() != expected_open {
None
} else {
Some(f(selected))
}
}
fn item_start_row(&self) -> usize {
usize::from(self.title.as_ref().is_some_and(|title| !title.is_empty()))
+ usize::from(
self.subtitle
.as_ref()
.is_some_and(|subtitle| !subtitle.is_empty()),
)
}
fn clamp_selection(&mut self) {
self.selected = self.normalized_selected();
}
fn normalized_selected(&self) -> usize {
self.selected.min(self.items.len().saturating_sub(1))
}
fn default_item_color(&self, item: &TreePickerItem) -> Color {
if item.is_branch() {
self.branch_color
} else {
self.leaf_color
}
}
fn indent_for_width(&self, width: usize) -> usize {
self.indent.min(width).min(MAX_TREE_PICKER_INDENT)
}
fn item_prefix_for_width(&self, item: &TreePickerItem, width: usize) -> String {
let tail = truncate_visible(&self.item_prefix_tail(item), width);
let tail_width = visible_len(&tail);
let indent = self.indent.min(width.saturating_sub(tail_width));
let depth_width = self
.item_depth_width_for_element(item)
.min(width.saturating_sub(indent).saturating_sub(tail_width));
format!("{}{}{}", " ".repeat(indent), " ".repeat(depth_width), tail)
}
fn item_prefix_for_element(&self, item: &TreePickerItem) -> String {
format!(
"{}{}{}",
" ".repeat(self.indent_for_element()),
" ".repeat(self.item_depth_width_for_element(item)),
self.item_prefix_tail(item)
)
}
fn item_prefix_tail(&self, item: &TreePickerItem) -> String {
format!("{} ", self.item_marker(item))
}
fn item_marker(&self, item: &TreePickerItem) -> &str {
match item.kind {
TreePickerItemKind::Branch { open: true } => self.open_marker.as_str(),
TreePickerItemKind::Branch { open: false } => self.closed_marker.as_str(),
TreePickerItemKind::Leaf => self.leaf_marker.as_str(),
}
}
fn item_depth_width_for_element(&self, item: &TreePickerItem) -> usize {
item.depth
.saturating_mul(self.depth_indent)
.min(MAX_TREE_PICKER_DEPTH_WIDTH)
}
fn indent_for_element(&self) -> usize {
self.indent.min(MAX_TREE_PICKER_INDENT)
}
}
impl Default for TreePicker {
fn default() -> Self {
Self::without_title()
}
}
impl Selectable for TreePicker {
fn item_count(&self) -> usize {
self.items.len()
}
fn selected_index(&self) -> Option<usize> {
(!self.items.is_empty()).then(|| self.normalized_selected())
}
fn select_index(&mut self, index: usize) {
self.selected = index;
self.clamp_selection();
}
}
impl Scrollable for TreePicker {
fn scroll_offset(&self) -> usize {
self.scroll
}
fn set_scroll_offset(&mut self, offset: usize) {
self.scroll = offset.min(self.items.len().saturating_sub(1));
}
}
impl Activatable for TreePicker {
fn is_item_disabled(&self, index: usize) -> bool {
self.items
.get(index)
.is_some_and(TreePickerItem::is_disabled)
}
}
#[cfg(test)]
mod tests {
use super::*;
use crate::style::{strip_ansi, visible_len};
use crossterm::event::KeyModifiers;
fn sample() -> TreePicker {
TreePicker::new("@ file")
.subtitle("↑/↓ · →/← folder · Enter · Esc")
.items(vec![
TreePickerItem::branch("src").open(true),
TreePickerItem::leaf("main.rs").depth(1),
TreePickerItem::leaf("lib.rs").depth(1),
TreePickerItem::branch("tests").open(false),
TreePickerItem::leaf("README.md"),
])
.selected(1)
.footer("5 files")
}
fn key(code: KeyCode) -> KeyEvent {
KeyEvent {
code,
modifiers: KeyModifiers::NONE,
}
}
#[test]
fn with_theme_applies_semantic_colors() {
let theme = Theme::tokyo_night();
let picker = TreePicker::without_title().with_theme(&theme);
assert_eq!(picker.title_color, theme.color(ThemeRole::Primary));
assert_eq!(picker.subtitle_color, theme.color(ThemeRole::Muted));
assert_eq!(picker.branch_color, theme.color(ThemeRole::Primary));
assert_eq!(picker.leaf_color, theme.color(ThemeRole::Foreground));
assert_eq!(picker.selected_bg, theme.color(ThemeRole::Highlight));
assert_eq!(picker.disabled_color, theme.color(ThemeRole::Muted));
}
#[test]
fn renders_open_closed_and_leaf_rows() {
let rendered = sample().view(48, 8);
let plain = strip_ansi(&rendered);
assert!(plain.contains("@ file"));
assert!(plain.contains("▾ src"));
assert!(plain.contains(" main.rs"));
assert!(plain.contains("▸ tests"));
assert!(plain.contains("5 files"));
assert_eq!(rendered.lines().count(), 8);
for line in rendered.lines() {
assert_eq!(visible_len(line), 48, "{line:?}");
}
}
#[test]
fn scroll_keeps_selected_item_visible() {
let items = (0..20)
.map(|idx| TreePickerItem::leaf(format!("file-{idx}.rs")))
.collect::<Vec<_>>();
let rendered = TreePicker::new("@ file")
.items(items)
.selected(18)
.max_items(4)
.view(32, 6);
let plain = strip_ansi(&rendered);
assert!(plain.contains("file-18.rs"), "{plain:?}");
assert!(!plain.contains("file-0.rs"), "{plain:?}");
}
#[test]
fn cjk_labels_fit_requested_width() {
let rendered = TreePicker::new("@ file")
.item(TreePickerItem::branch("源码目录").open(true))
.item(
TreePickerItem::leaf("组件测试文件-with-a-long-tail.rs")
.depth(1)
.description("modified"),
)
.selected(1)
.view(24, 4);
assert!(strip_ansi(&rendered).contains("组件"));
for line in rendered.lines() {
assert_eq!(visible_len(line), 24, "{line:?}");
}
}
#[test]
fn oversized_spacing_is_clamped_to_render_width() {
let picker = TreePicker::new("@ file")
.subtitle("hint")
.indent(usize::MAX)
.depth_indent(usize::MAX)
.item(
TreePickerItem::branch("src")
.depth(usize::MAX)
.description("dir"),
)
.footer("footer")
.fill_height(true);
let rendered = picker.view(8, 4);
let item = picker.items.first().unwrap();
let prefix = picker.item_prefix_for_width(item, 8);
let line = picker.plain_item_line(0, Some(8));
assert_eq!(picker.indent, MAX_TREE_PICKER_INDENT);
assert_eq!(picker.depth_indent, MAX_TREE_PICKER_DEPTH_INDENT);
assert_eq!(item.depth, MAX_TREE_PICKER_ITEM_DEPTH);
assert_eq!(picker.indent_for_width(8), 8);
assert_eq!(visible_len(&prefix), 8);
assert_eq!(visible_len(&line), 8);
assert!(rendered.lines().all(|line| visible_len(line) == 8));
let Element::Box(column) = picker.element::<()>() else {
panic!("expected column element");
};
let Element::Text(item) = &column.children[2] else {
panic!("expected item text");
};
assert_eq!(
visible_len(&item.content),
MAX_TREE_PICKER_INDENT + MAX_TREE_PICKER_DEPTH_WIDTH + visible_len("▸ src dir")
);
}
#[test]
fn oversized_item_limit_is_clamped() {
let picker = TreePicker::new("@ file")
.max_items(usize::MAX)
.item(TreePickerItem::branch("src").open(true))
.item(TreePickerItem::leaf("main.rs").depth(1));
let rendered = picker.view(24, 4);
assert_eq!(picker.max_items, Some(MAX_TREE_PICKER_ITEMS));
assert!(rendered.lines().all(|line| visible_len(line) == 24));
}
#[test]
fn key_handling_moves_and_emits_tree_actions() {
let mut picker = sample();
assert_eq!(picker.selected_index(), 1);
assert_eq!(
picker.handle_key(&key(KeyCode::Enter)),
Some(TreePickerMsg::Selected(1))
);
assert_eq!(picker.handle_key(&key(KeyCode::Down)), None);
assert_eq!(picker.handle_key(&key(KeyCode::Down)), None);
assert_eq!(picker.selected_index(), 3);
assert_eq!(
picker.handle_key(&key(KeyCode::Right)),
Some(TreePickerMsg::Opened(3))
);
assert_eq!(
picker.handle_key(&key(KeyCode::Enter)),
Some(TreePickerMsg::Toggled(3))
);
let mut opened = sample().selected(0);
assert_eq!(
opened.handle_key(&key(KeyCode::Left)),
Some(TreePickerMsg::Closed(0))
);
assert_eq!(
opened.handle_key(&key(KeyCode::Esc)),
Some(TreePickerMsg::Cancelled)
);
}
#[test]
fn huge_page_down_saturates_selection() {
let mut picker = sample().selected(1).max_items(usize::MAX);
assert_eq!(picker.handle_key(&key(KeyCode::PageDown)), None);
assert_eq!(picker.selected_index(), picker.items_value().len() - 1);
}
#[test]
fn stale_selection_is_normalized_for_rendering_and_input() {
let mut picker = TreePicker::without_title()
.max_items(1)
.item(TreePickerItem::leaf("one"))
.item(TreePickerItem::leaf("two"));
picker.selected = usize::MAX;
assert_eq!(picker.selected_index(), 1);
assert_eq!(
picker.selected_item().map(TreePickerItem::label),
Some("two")
);
assert_eq!(
picker.handle_key(&key(KeyCode::Enter)),
Some(TreePickerMsg::Selected(1))
);
let plain = strip_ansi(&picker.view(24, 2));
assert!(plain.contains("two"), "{plain:?}");
assert!(!plain.contains("one"), "{plain:?}");
assert!(plain.contains("2/2"), "{plain:?}");
let Element::Box(column) = picker.element::<()>() else {
panic!("expected column element");
};
assert_eq!(column.children.len(), 1);
let Element::Text(selected_item) = &column.children[0] else {
panic!("expected selected item");
};
assert_eq!(selected_item.content, " two");
assert_eq!(selected_item.style.bg, Some(Color::Cyan));
assert_eq!(picker.handle_key(&key(KeyCode::Down)), None);
assert_eq!(picker.selected_index(), 1);
assert_eq!(picker.handle_key(&key(KeyCode::Up)), None);
assert_eq!(picker.selected_index(), 0);
}
#[test]
fn disabled_items_do_not_emit_actions() {
let mut picker = TreePicker::new("@ file")
.item(TreePickerItem::branch("target").disabled(true))
.item(TreePickerItem::leaf("main.rs"))
.selected(0);
assert_eq!(picker.handle_key(&key(KeyCode::Enter)), None);
assert_eq!(picker.handle_key(&key(KeyCode::Right)), None);
}
#[test]
fn mouse_click_above_offset_is_ignored() {
let mut picker = sample();
picker.set_y_offset(4);
let msg = picker.handle_mouse(&MouseEvent {
kind: MouseEventKind::Down(MouseButton::Left),
column: 0,
row: 3,
modifiers: KeyModifiers::NONE,
});
assert_eq!(msg, None);
assert_eq!(picker.selected_index(), 1);
}
#[test]
fn mouse_wheel_updates_selected_tree_item() {
let mut picker = sample();
assert_eq!(
picker.handle_mouse(&MouseEvent {
kind: MouseEventKind::ScrollDown,
column: 0,
row: 2,
modifiers: KeyModifiers::NONE,
}),
None
);
assert_eq!(picker.selected_index(), 2);
assert_eq!(
picker.handle_mouse(&MouseEvent {
kind: MouseEventKind::ScrollUp,
column: 0,
row: 2,
modifiers: KeyModifiers::NONE,
}),
None
);
assert_eq!(picker.selected_index(), 1);
}
#[test]
fn mouse_wheel_above_offset_is_ignored() {
let mut picker = sample();
picker.set_y_offset(4);
let msg = picker.handle_mouse(&MouseEvent {
kind: MouseEventKind::ScrollDown,
column: 0,
row: 3,
modifiers: KeyModifiers::NONE,
});
assert_eq!(msg, None);
assert_eq!(picker.selected_index(), 1);
}
#[test]
fn zero_size_renders_empty_string() {
assert_eq!(sample().view(0, 8), "");
assert_eq!(sample().view(40, 0), "");
}
#[test]
fn element_produces_column() {
let el: Element<()> = sample().element();
match el {
Element::Box(column) => {
assert_eq!(column.style.flex_direction, FlexDirection::Column);
assert!(!column.children.is_empty());
}
_ => panic!("expected Box"),
}
}
#[test]
fn element_respects_max_items_window() {
let items = (0..5)
.map(|idx| TreePickerItem::leaf(format!("file-{idx}.rs")))
.collect::<Vec<_>>();
let el: Element<()> = TreePicker::without_title()
.items(items)
.selected(3)
.scroll(1)
.max_items(3)
.element();
let Element::Box(column) = el else {
panic!("expected column");
};
let text = column
.children
.iter()
.filter_map(Element::text_content)
.collect::<Vec<_>>()
.join("\n");
assert!(text.contains("file-1.rs"));
assert!(text.contains("file-2.rs"));
assert!(text.contains("file-3.rs"));
assert!(!text.contains("file-0.rs"));
assert!(!text.contains("file-4.rs"));
}
#[test]
fn element_with_height_zero_returns_empty_column() {
let el: Element<()> = sample().element_with_height(0);
let Element::Box(column) = el else {
panic!("expected column");
};
assert!(column.children.is_empty());
}
#[test]
fn element_with_height_limits_items_and_keeps_scroll_footer() {
let items = (0..6)
.map(|idx| TreePickerItem::leaf(format!("file-{idx}.rs")))
.collect::<Vec<_>>();
let el: Element<()> = TreePicker::without_title()
.items(items)
.selected(4)
.scroll(2)
.element_with_height(4);
let Element::Box(column) = el else {
panic!("expected column");
};
let text = column
.children
.iter()
.filter_map(Element::text_content)
.collect::<Vec<_>>()
.join("\n");
assert_eq!(column.children.len(), 4);
assert!(text.contains("file-2.rs"), "{text:?}");
assert!(text.contains("file-4.rs"), "{text:?}");
assert!(text.contains("5/6"), "{text:?}");
assert!(!text.contains("file-0.rs"), "{text:?}");
}
#[test]
fn element_with_height_fill_height_pads_empty_rows() {
let el: Element<()> = TreePicker::without_title()
.item(TreePickerItem::leaf("only.rs"))
.fill_height(true)
.element_with_height(3);
let Element::Box(column) = el else {
panic!("expected column");
};
let rows = column
.children
.iter()
.filter_map(Element::text_content)
.collect::<Vec<_>>();
assert_eq!(rows.len(), 3);
assert_eq!(rows[0], " only.rs");
assert_eq!(rows[1], "");
assert_eq!(rows[2], "");
}
}