Files
ratatui/src/widgets/list.rs
Orhun Parmaksız c862aa5e9e feat(list): support line alignment (#599)
The `List` widget now respects the alignment of `Line`s and renders them as expected.
2023-11-23 11:52:12 -08:00

1233 lines
38 KiB
Rust

use unicode_width::UnicodeWidthStr;
use crate::{
buffer::Buffer,
layout::{Alignment, Corner, Rect},
style::{Style, Styled},
text::Text,
widgets::{Block, HighlightSpacing, StatefulWidget, Widget},
};
#[derive(Debug, Default, Clone, Eq, PartialEq, Hash)]
pub struct ListState {
offset: usize,
selected: Option<usize>,
}
impl ListState {
pub fn offset(&self) -> usize {
self.offset
}
pub fn offset_mut(&mut self) -> &mut usize {
&mut self.offset
}
pub fn with_selected(mut self, selected: Option<usize>) -> Self {
self.selected = selected;
self
}
pub fn with_offset(mut self, offset: usize) -> Self {
self.offset = offset;
self
}
pub fn selected(&self) -> Option<usize> {
self.selected
}
pub fn select(&mut self, index: Option<usize>) {
self.selected = index;
if index.is_none() {
self.offset = 0;
}
}
}
#[derive(Debug, Clone, Eq, PartialEq, Hash)]
pub struct ListItem<'a> {
content: Text<'a>,
style: Style,
}
impl<'a> ListItem<'a> {
pub fn new<T>(content: T) -> ListItem<'a>
where
T: Into<Text<'a>>,
{
ListItem {
content: content.into(),
style: Style::default(),
}
}
pub fn style(mut self, style: Style) -> ListItem<'a> {
self.style = style;
self
}
pub fn height(&self) -> usize {
self.content.height()
}
pub fn width(&self) -> usize {
self.content.width()
}
}
/// A widget to display several items among which one can be selected (optional)
///
/// # Examples
///
/// ```
/// use ratatui::{prelude::*, widgets::*};
///
/// let items = [ListItem::new("Item 1"), ListItem::new("Item 2"), ListItem::new("Item 3")];
/// List::new(items)
/// .block(Block::default().title("List").borders(Borders::ALL))
/// .style(Style::default().fg(Color::White))
/// .highlight_style(Style::default().add_modifier(Modifier::ITALIC))
/// .highlight_symbol(">>");
/// ```
#[derive(Debug, Clone, Eq, PartialEq, Hash)]
pub struct List<'a> {
block: Option<Block<'a>>,
items: Vec<ListItem<'a>>,
/// Style used as a base style for the widget
style: Style,
start_corner: Corner,
/// Style used to render selected item
highlight_style: Style,
/// Symbol in front of the selected item (Shift all items to the right)
highlight_symbol: Option<&'a str>,
/// Whether to repeat the highlight symbol for each line of the selected item
repeat_highlight_symbol: bool,
/// Decides when to allocate spacing for the selection symbol
highlight_spacing: HighlightSpacing,
}
impl<'a> List<'a> {
pub fn new<T>(items: T) -> List<'a>
where
T: Into<Vec<ListItem<'a>>>,
{
List {
block: None,
style: Style::default(),
items: items.into(),
start_corner: Corner::TopLeft,
highlight_style: Style::default(),
highlight_symbol: None,
repeat_highlight_symbol: false,
highlight_spacing: HighlightSpacing::default(),
}
}
pub fn block(mut self, block: Block<'a>) -> List<'a> {
self.block = Some(block);
self
}
pub fn style(mut self, style: Style) -> List<'a> {
self.style = style;
self
}
pub fn highlight_symbol(mut self, highlight_symbol: &'a str) -> List<'a> {
self.highlight_symbol = Some(highlight_symbol);
self
}
pub fn highlight_style(mut self, style: Style) -> List<'a> {
self.highlight_style = style;
self
}
pub fn repeat_highlight_symbol(mut self, repeat: bool) -> List<'a> {
self.repeat_highlight_symbol = repeat;
self
}
/// Set when to show the highlight spacing
///
/// See [`HighlightSpacing`] about which variant affects spacing in which way
pub fn highlight_spacing(mut self, value: HighlightSpacing) -> Self {
self.highlight_spacing = value;
self
}
pub fn start_corner(mut self, corner: Corner) -> List<'a> {
self.start_corner = corner;
self
}
pub fn len(&self) -> usize {
self.items.len()
}
pub fn is_empty(&self) -> bool {
self.items.is_empty()
}
fn get_items_bounds(
&self,
selected: Option<usize>,
offset: usize,
max_height: usize,
) -> (usize, usize) {
let offset = offset.min(self.items.len().saturating_sub(1));
let mut start = offset;
let mut end = offset;
let mut height = 0;
for item in self.items.iter().skip(offset) {
if height + item.height() > max_height {
break;
}
height += item.height();
end += 1;
}
let selected = selected.unwrap_or(0).min(self.items.len() - 1);
while selected >= end {
height = height.saturating_add(self.items[end].height());
end += 1;
while height > max_height {
height = height.saturating_sub(self.items[start].height());
start += 1;
}
}
while selected < start {
start -= 1;
height = height.saturating_add(self.items[start].height());
while height > max_height {
end -= 1;
height = height.saturating_sub(self.items[end].height());
}
}
(start, end)
}
}
impl<'a> StatefulWidget for List<'a> {
type State = ListState;
fn render(mut self, area: Rect, buf: &mut Buffer, state: &mut Self::State) {
buf.set_style(area, self.style);
let list_area = match self.block.take() {
Some(b) => {
let inner_area = b.inner(area);
b.render(area, buf);
inner_area
}
None => area,
};
if list_area.width < 1 || list_area.height < 1 {
return;
}
if self.items.is_empty() {
return;
}
let list_height = list_area.height as usize;
let (start, end) = self.get_items_bounds(state.selected, state.offset, list_height);
state.offset = start;
let highlight_symbol = self.highlight_symbol.unwrap_or("");
let blank_symbol = " ".repeat(highlight_symbol.width());
let mut current_height = 0;
let selection_spacing = self.highlight_spacing.should_add(state.selected.is_some());
for (i, item) in self
.items
.iter_mut()
.enumerate()
.skip(state.offset)
.take(end - start)
{
let (x, y) = if self.start_corner == Corner::BottomLeft {
current_height += item.height() as u16;
(list_area.left(), list_area.bottom() - current_height)
} else {
let pos = (list_area.left(), list_area.top() + current_height);
current_height += item.height() as u16;
pos
};
let area = Rect {
x,
y,
width: list_area.width,
height: item.height() as u16,
};
let item_style = self.style.patch(item.style);
buf.set_style(area, item_style);
let is_selected = state.selected.map_or(false, |s| s == i);
for (j, line) in item.content.lines.iter().enumerate() {
// if the item is selected, we need to display the highlight symbol:
// - either for the first line of the item only,
// - or for each line of the item if the appropriate option is set
let symbol = if is_selected && (j == 0 || self.repeat_highlight_symbol) {
highlight_symbol
} else {
&blank_symbol
};
let (elem_x, max_element_width) = if selection_spacing {
let (elem_x, _) = buf.set_stringn(
x,
y + j as u16,
symbol,
list_area.width as usize,
item_style,
);
(elem_x, (list_area.width - (elem_x - x)))
} else {
(x, list_area.width)
};
let x_offset = match line.alignment {
Some(Alignment::Center) => {
(area.width / 2).saturating_sub(line.width() as u16 / 2)
}
Some(Alignment::Right) => area.width.saturating_sub(line.width() as u16),
_ => 0,
};
buf.set_line(elem_x + x_offset, y + j as u16, line, max_element_width);
}
if is_selected {
buf.set_style(area, self.highlight_style);
}
}
}
}
impl<'a> Widget for List<'a> {
fn render(self, area: Rect, buf: &mut Buffer) {
let mut state = ListState::default();
StatefulWidget::render(self, area, buf, &mut state);
}
}
impl<'a> Styled for List<'a> {
type Item = List<'a>;
fn style(&self) -> Style {
self.style
}
fn set_style(self, style: Style) -> Self::Item {
self.style(style)
}
}
impl<'a> Styled for ListItem<'a> {
type Item = ListItem<'a>;
fn style(&self) -> Style {
self.style
}
fn set_style(self, style: Style) -> Self::Item {
self.style(style)
}
}
#[cfg(test)]
mod tests {
use std::borrow::Cow;
use super::*;
use crate::{
assert_buffer_eq,
prelude::Alignment,
style::{Color, Modifier, Stylize},
text::{Line, Span},
widgets::{Borders, StatefulWidget, Widget},
};
#[test]
fn test_list_state_selected() {
let mut state = ListState::default();
assert_eq!(state.selected(), None);
state.select(Some(1));
assert_eq!(state.selected(), Some(1));
state.select(None);
assert_eq!(state.selected(), None);
}
#[test]
fn test_list_state_select() {
let mut state = ListState::default();
assert_eq!(state.selected, None);
assert_eq!(state.offset, 0);
state.select(Some(2));
assert_eq!(state.selected, Some(2));
assert_eq!(state.offset, 0);
state.select(None);
assert_eq!(state.selected, None);
assert_eq!(state.offset, 0);
}
#[test]
fn test_list_item_new_from_str() {
let item = ListItem::new("Test item");
assert_eq!(item.content, Text::from("Test item"));
assert_eq!(item.style, Style::default());
}
#[test]
fn test_list_item_new_from_string() {
let item = ListItem::new("Test item".to_string());
assert_eq!(item.content, Text::from("Test item"));
assert_eq!(item.style, Style::default());
}
#[test]
fn test_list_item_new_from_cow_str() {
let item = ListItem::new(Cow::Borrowed("Test item"));
assert_eq!(item.content, Text::from("Test item"));
assert_eq!(item.style, Style::default());
}
#[test]
fn test_list_item_new_from_span() {
let span = Span::styled("Test item", Style::default().fg(Color::Blue));
let item = ListItem::new(span.clone());
assert_eq!(item.content, Text::from(span));
assert_eq!(item.style, Style::default());
}
#[test]
fn test_list_item_new_from_spans() {
let spans = Line::from(vec![
Span::styled("Test ", Style::default().fg(Color::Blue)),
Span::styled("item", Style::default().fg(Color::Red)),
]);
let item = ListItem::new(spans.clone());
assert_eq!(item.content, Text::from(spans));
assert_eq!(item.style, Style::default());
}
#[test]
fn test_list_item_new_from_vec_spans() {
let lines = vec![
Line::from(vec![
Span::styled("Test ", Style::default().fg(Color::Blue)),
Span::styled("item", Style::default().fg(Color::Red)),
]),
Line::from(vec![
Span::styled("Second ", Style::default().fg(Color::Green)),
Span::styled("line", Style::default().fg(Color::Yellow)),
]),
];
let item = ListItem::new(lines.clone());
assert_eq!(item.content, Text::from(lines));
assert_eq!(item.style, Style::default());
}
#[test]
fn test_list_item_style() {
let item = ListItem::new("Test item").style(Style::default().bg(Color::Red));
assert_eq!(item.content, Text::from("Test item"));
assert_eq!(item.style, Style::default().bg(Color::Red));
}
#[test]
fn test_list_item_height() {
let item = ListItem::new("Test item");
assert_eq!(item.height(), 1);
let item = ListItem::new("Test item\nSecond line");
assert_eq!(item.height(), 2);
}
#[test]
fn test_list_item_width() {
let item = ListItem::new("Test item");
assert_eq!(item.width(), 9);
}
/// helper method to take a vector of strings and return a vector of list items
fn list_items(items: Vec<&str>) -> Vec<ListItem> {
items.iter().map(|i| ListItem::new(i.to_string())).collect()
}
/// helper method to render a widget to an empty buffer with the default state
fn render_widget(widget: List<'_>, width: u16, height: u16) -> Buffer {
let mut buffer = Buffer::empty(Rect::new(0, 0, width, height));
Widget::render(widget, buffer.area, &mut buffer);
buffer
}
/// helper method to render a widget to an empty buffer with a given state
fn render_stateful_widget(
widget: List<'_>,
state: &mut ListState,
width: u16,
height: u16,
) -> Buffer {
let mut buffer = Buffer::empty(Rect::new(0, 0, width, height));
StatefulWidget::render(widget, buffer.area, &mut buffer, state);
buffer
}
#[test]
fn test_list_does_not_render_in_small_space() {
let items = list_items(vec!["Item 0", "Item 1", "Item 2"]);
let list = List::new(items.clone()).highlight_symbol(">>");
let mut buffer = Buffer::empty(Rect::new(0, 0, 15, 3));
// attempt to render into an area of the buffer with 0 width
Widget::render(list.clone(), Rect::new(0, 0, 0, 3), &mut buffer);
assert_buffer_eq!(buffer, Buffer::empty(buffer.area));
// attempt to render into an area of the buffer with 0 height
Widget::render(list.clone(), Rect::new(0, 0, 15, 0), &mut buffer);
assert_buffer_eq!(buffer, Buffer::empty(buffer.area));
let list = List::new(items)
.highlight_symbol(">>")
.block(Block::default().borders(Borders::all()));
// attempt to render into an area of the buffer with zero height after
// setting the block borders
Widget::render(list, Rect::new(0, 0, 15, 2), &mut buffer);
assert_buffer_eq!(
buffer,
Buffer::with_lines(vec![
"┌─────────────┐",
"└─────────────┘",
" "
])
);
}
#[test]
fn test_list_combinations() {
fn test_case_render(items: &[ListItem], expected_lines: Vec<&str>) {
let list = List::new(items.to_owned()).highlight_symbol(">>");
let mut buffer = Buffer::empty(Rect::new(0, 0, 10, 5));
Widget::render(list, buffer.area, &mut buffer);
let expected = Buffer::with_lines(expected_lines);
assert_buffer_eq!(buffer, expected);
}
fn test_case_render_stateful(
items: &[ListItem],
selected: Option<usize>,
expected_lines: Vec<&str>,
) {
let list = List::new(items.to_owned()).highlight_symbol(">>");
let mut state = ListState::default().with_selected(selected);
let mut buffer = Buffer::empty(Rect::new(0, 0, 10, 5));
StatefulWidget::render(list, buffer.area, &mut buffer, &mut state);
let expected = Buffer::with_lines(expected_lines);
assert_buffer_eq!(buffer, expected);
}
let empty_items: Vec<ListItem> = Vec::new();
let single_item = list_items(vec!["Item 0"]);
let multiple_items = list_items(vec!["Item 0", "Item 1", "Item 2"]);
let multi_line_items = list_items(vec!["Item 0\nLine 2", "Item 1", "Item 2"]);
// empty list
test_case_render(
&empty_items,
vec![
" ",
" ",
" ",
" ",
" ",
],
);
test_case_render_stateful(
&empty_items,
None,
vec![
" ",
" ",
" ",
" ",
" ",
],
);
test_case_render_stateful(
&empty_items,
Some(0),
vec![
" ",
" ",
" ",
" ",
" ",
],
);
// single item
test_case_render(
&single_item,
vec![
"Item 0 ",
" ",
" ",
" ",
" ",
],
);
test_case_render_stateful(
&single_item,
None,
vec![
"Item 0 ",
" ",
" ",
" ",
" ",
],
);
test_case_render_stateful(
&single_item,
Some(0),
vec![
">>Item 0 ",
" ",
" ",
" ",
" ",
],
);
test_case_render_stateful(
&single_item,
Some(1),
vec![
" Item 0 ",
" ",
" ",
" ",
" ",
],
);
// multiple items
test_case_render(
&multiple_items,
vec![
"Item 0 ",
"Item 1 ",
"Item 2 ",
" ",
" ",
],
);
test_case_render_stateful(
&multiple_items,
None,
vec![
"Item 0 ",
"Item 1 ",
"Item 2 ",
" ",
" ",
],
);
test_case_render_stateful(
&multiple_items,
Some(0),
vec![
">>Item 0 ",
" Item 1 ",
" Item 2 ",
" ",
" ",
],
);
test_case_render_stateful(
&multiple_items,
Some(1),
vec![
" Item 0 ",
">>Item 1 ",
" Item 2 ",
" ",
" ",
],
);
test_case_render_stateful(
&multiple_items,
Some(3),
vec![
" Item 0 ",
" Item 1 ",
" Item 2 ",
" ",
" ",
],
);
// multi line items
test_case_render(
&multi_line_items,
vec![
"Item 0 ",
"Line 2 ",
"Item 1 ",
"Item 2 ",
" ",
],
);
test_case_render_stateful(
&multi_line_items,
None,
vec![
"Item 0 ",
"Line 2 ",
"Item 1 ",
"Item 2 ",
" ",
],
);
test_case_render_stateful(
&multi_line_items,
Some(0),
vec![
">>Item 0 ",
" Line 2 ",
" Item 1 ",
" Item 2 ",
" ",
],
);
test_case_render_stateful(
&multi_line_items,
Some(1),
vec![
" Item 0 ",
" Line 2 ",
">>Item 1 ",
" Item 2 ",
" ",
],
);
}
#[test]
fn test_list_with_empty_strings() {
let items = list_items(vec!["Item 0", "", "", "Item 1", "Item 2"]);
let list = List::new(items).block(Block::default().title("List").borders(Borders::ALL));
let buffer = render_widget(list, 10, 7);
let expected = Buffer::with_lines(vec![
"┌List────┐",
"│Item 0 │",
"│ │",
"│ │",
"│Item 1 │",
"│Item 2 │",
"└────────┘",
]);
assert_buffer_eq!(buffer, expected);
}
#[test]
fn test_list_block() {
let items = list_items(vec!["Item 0", "Item 1", "Item 2"]);
let list = List::new(items).block(Block::default().title("List").borders(Borders::ALL));
let buffer = render_widget(list, 10, 7);
let expected = Buffer::with_lines(vec![
"┌List────┐",
"│Item 0 │",
"│Item 1 │",
"│Item 2 │",
"│ │",
"│ │",
"└────────┘",
]);
assert_buffer_eq!(buffer, expected);
}
#[test]
fn test_list_style() {
let items = list_items(vec!["Item 0", "Item 1", "Item 2"]);
let list = List::new(items).style(Style::default().fg(Color::Red));
assert_buffer_eq!(
render_widget(list, 10, 5),
Buffer::with_lines(vec![
"Item 0 ".red(),
"Item 1 ".red(),
"Item 2 ".red(),
" ".red(),
" ".red(),
])
);
}
#[test]
fn test_list_highlight_symbol_and_style() {
let items = list_items(vec!["Item 0", "Item 1", "Item 2"]);
let list = List::new(items)
.highlight_symbol(">>")
.highlight_style(Style::default().fg(Color::Yellow));
let mut state = ListState::default();
state.select(Some(1));
assert_buffer_eq!(
render_stateful_widget(list, &mut state, 10, 5),
Buffer::with_lines(vec![
" Item 0 ".into(),
">>Item 1 ".yellow(),
" Item 2 ".into(),
" ".into(),
" ".into(),
])
);
}
#[test]
fn test_list_highlight_spacing_default_whenselected() {
// when not selected
{
let items = list_items(vec!["Item 0", "Item 1", "Item 2"]);
let list = List::new(items).highlight_symbol(">>");
let mut state = ListState::default();
let buffer = render_stateful_widget(list, &mut state, 10, 5);
let expected = Buffer::with_lines(vec![
"Item 0 ",
"Item 1 ",
"Item 2 ",
" ",
" ",
]);
assert_buffer_eq!(buffer, expected);
}
// when selected
{
let items = list_items(vec!["Item 0", "Item 1", "Item 2"]);
let list = List::new(items).highlight_symbol(">>");
let mut state = ListState::default();
state.select(Some(1));
let buffer = render_stateful_widget(list, &mut state, 10, 5);
let expected = Buffer::with_lines(vec![
" Item 0 ",
">>Item 1 ",
" Item 2 ",
" ",
" ",
]);
assert_buffer_eq!(buffer, expected);
}
}
#[test]
fn test_list_highlight_spacing_default_always() {
// when not selected
{
let items = list_items(vec!["Item 0", "Item 1", "Item 2"]);
let list = List::new(items)
.highlight_symbol(">>")
.highlight_spacing(HighlightSpacing::Always);
let mut state = ListState::default();
let buffer = render_stateful_widget(list, &mut state, 10, 5);
let expected = Buffer::with_lines(vec![
" Item 0 ",
" Item 1 ",
" Item 2 ",
" ",
" ",
]);
assert_buffer_eq!(buffer, expected);
}
// when selected
{
let items = list_items(vec!["Item 0", "Item 1", "Item 2"]);
let list = List::new(items)
.highlight_symbol(">>")
.highlight_spacing(HighlightSpacing::Always);
let mut state = ListState::default();
state.select(Some(1));
let buffer = render_stateful_widget(list, &mut state, 10, 5);
let expected = Buffer::with_lines(vec![
" Item 0 ",
">>Item 1 ",
" Item 2 ",
" ",
" ",
]);
assert_buffer_eq!(buffer, expected);
}
}
#[test]
fn test_list_highlight_spacing_default_never() {
// when not selected
{
let items = list_items(vec!["Item 0", "Item 1", "Item 2"]);
let list = List::new(items)
.highlight_symbol(">>")
.highlight_spacing(HighlightSpacing::Never);
let mut state = ListState::default();
let buffer = render_stateful_widget(list, &mut state, 10, 5);
let expected = Buffer::with_lines(vec![
"Item 0 ",
"Item 1 ",
"Item 2 ",
" ",
" ",
]);
assert_buffer_eq!(buffer, expected);
}
// when selected
{
let items = list_items(vec!["Item 0", "Item 1", "Item 2"]);
let list = List::new(items)
.highlight_symbol(">>")
.highlight_spacing(HighlightSpacing::Never);
let mut state = ListState::default();
state.select(Some(1));
let buffer = render_stateful_widget(list, &mut state, 10, 5);
let expected = Buffer::with_lines(vec![
"Item 0 ",
"Item 1 ",
"Item 2 ",
" ",
" ",
]);
assert_buffer_eq!(buffer, expected);
}
}
#[test]
fn test_list_repeat_highlight_symbol() {
let items = list_items(vec!["Item 0\nLine 2", "Item 1", "Item 2"]);
let list = List::new(items)
.highlight_symbol(">>")
.highlight_style(Style::default().fg(Color::Yellow))
.repeat_highlight_symbol(true);
let mut state = ListState::default();
state.select(Some(0));
assert_buffer_eq!(
render_stateful_widget(list, &mut state, 10, 5),
Buffer::with_lines(vec![
">>Item 0 ".yellow(),
">>Line 2 ".yellow(),
" Item 1 ".into(),
" Item 2 ".into(),
" ".into(),
])
);
}
#[test]
fn test_list_start_corner_top_left() {
let items = list_items(vec!["Item 0", "Item 1", "Item 2"]);
let list = List::new(items).start_corner(Corner::TopLeft);
let buffer = render_widget(list, 10, 5);
let expected = Buffer::with_lines(vec![
"Item 0 ",
"Item 1 ",
"Item 2 ",
" ",
" ",
]);
assert_buffer_eq!(buffer, expected);
}
#[test]
fn test_list_start_corner_bottom_left() {
let items = list_items(vec!["Item 0", "Item 1", "Item 2"]);
let list = List::new(items).start_corner(Corner::BottomLeft);
let buffer = render_widget(list, 10, 5);
let expected = Buffer::with_lines(vec![
" ",
" ",
"Item 2 ",
"Item 1 ",
"Item 0 ",
]);
assert_buffer_eq!(buffer, expected);
}
#[test]
fn test_list_truncate_items() {
let items = list_items(vec!["Item 0", "Item 1", "Item 2", "Item 3", "Item 4"]);
let list = List::new(items);
let buffer = render_widget(list, 10, 3);
let expected = Buffer::with_lines(vec!["Item 0 ", "Item 1 ", "Item 2 "]);
assert_buffer_eq!(buffer, expected);
}
#[test]
fn test_list_long_lines() {
let items = list_items(vec![
"Item 0 with a very long line that will be truncated",
"Item 1",
"Item 2",
]);
let list = List::new(items).highlight_symbol(">>");
fn test_case(list: List, selected: Option<usize>, expected_lines: Vec<&str>) {
let mut state = ListState::default();
state.select(selected);
let buffer = render_stateful_widget(list.clone(), &mut state, 15, 3);
let expected = Buffer::with_lines(expected_lines);
assert_buffer_eq!(buffer, expected);
}
test_case(
list.clone(),
None,
vec!["Item 0 with a v", "Item 1 ", "Item 2 "],
);
test_case(
list,
Some(0),
vec![">>Item 0 with a", " Item 1 ", " Item 2 "],
);
}
#[test]
fn test_list_selected_item_ensures_selected_item_is_visible_when_offset_is_before_visible_range(
) {
let items = list_items(vec![
"Item 0", "Item 1", "Item 2", "Item 3", "Item 4", "Item 5", "Item 6",
]);
let list = List::new(items).highlight_symbol(">>");
// Set the initial visible range to items 3, 4, and 5
let mut state = ListState::default().with_selected(Some(1)).with_offset(3);
let buffer = render_stateful_widget(list, &mut state, 10, 3);
let expected = Buffer::with_lines(vec![">>Item 1 ", " Item 2 ", " Item 3 "]);
assert_buffer_eq!(buffer, expected);
assert_eq!(state.selected, Some(1));
assert_eq!(
state.offset, 1,
"did not scroll the selected item into view"
);
}
#[test]
fn test_list_selected_item_ensures_selected_item_is_visible_when_offset_is_after_visible_range()
{
let items = list_items(vec![
"Item 0", "Item 1", "Item 2", "Item 3", "Item 4", "Item 5", "Item 6",
]);
let list = List::new(items).highlight_symbol(">>");
// Set the initial visible range to items 3, 4, and 5
let mut state = ListState::default().with_selected(Some(6)).with_offset(3);
let buffer = render_stateful_widget(list, &mut state, 10, 3);
let expected = Buffer::with_lines(vec![" Item 4 ", " Item 5 ", ">>Item 6 "]);
assert_buffer_eq!(buffer, expected);
assert_eq!(state.selected, Some(6));
assert_eq!(
state.offset, 4,
"did not scroll the selected item into view"
);
}
#[test]
fn list_can_be_stylized() {
assert_eq!(
List::new(vec![]).black().on_white().bold().not_dim().style,
Style::default()
.fg(Color::Black)
.bg(Color::White)
.add_modifier(Modifier::BOLD)
.remove_modifier(Modifier::DIM)
)
}
#[test]
fn list_item_can_be_stylized() {
assert_eq!(
ListItem::new("").black().on_white().bold().not_dim().style,
Style::default()
.fg(Color::Black)
.bg(Color::White)
.add_modifier(Modifier::BOLD)
.remove_modifier(Modifier::DIM)
)
}
#[test]
fn test_render_list_with_alignment() {
let items = [
Line::from("Left").alignment(Alignment::Left),
Line::from("Center").alignment(Alignment::Center),
Line::from("Right").alignment(Alignment::Right),
]
.into_iter()
.map(ListItem::new)
.collect::<Vec<ListItem>>();
let list = List::new(items);
let buffer = render_widget(list, 10, 5);
let expected = Buffer::with_lines(vec![
"Left ",
" Center ",
" Right",
" ",
" ",
]);
assert_buffer_eq!(buffer, expected);
}
#[test]
fn test_render_list_alignment_odd_line_odd_area() {
let items = [
Line::from("Odd").alignment(Alignment::Left),
Line::from("Even").alignment(Alignment::Center),
Line::from("Width").alignment(Alignment::Right),
]
.into_iter()
.map(ListItem::new)
.collect::<Vec<ListItem>>();
let list = List::new(items);
let buffer = render_widget(list, 7, 5);
let expected =
Buffer::with_lines(vec!["Odd ", " Even ", " Width", " ", " "]);
assert_buffer_eq!(buffer, expected);
}
#[test]
fn test_render_list_alignment_even_line_even_area() {
let items = [
Line::from("Odd").alignment(Alignment::Left),
Line::from("Even").alignment(Alignment::Center),
Line::from("Width").alignment(Alignment::Right),
]
.into_iter()
.map(ListItem::new)
.collect::<Vec<ListItem>>();
let list = List::new(items);
let buffer = render_widget(list, 6, 4);
let expected = Buffer::with_lines(vec!["Odd ", " Even ", " Width", " "]);
assert_buffer_eq!(buffer, expected);
}
#[test]
fn test_render_list_alignment_odd_line_even_area() {
let items = [
Line::from("Odd").alignment(Alignment::Left),
Line::from("Even").alignment(Alignment::Center),
Line::from("Width").alignment(Alignment::Right),
]
.into_iter()
.map(ListItem::new)
.collect::<Vec<ListItem>>();
let list = List::new(items);
let buffer = render_widget(list, 8, 4);
let expected = Buffer::with_lines(vec!["Odd ", " Even ", " Width", " "]);
assert_buffer_eq!(buffer, expected);
}
#[test]
fn test_render_list_alignment_even_line_odd_area() {
let items = [
Line::from("Odd").alignment(Alignment::Left),
Line::from("Even").alignment(Alignment::Center),
Line::from("Width").alignment(Alignment::Right),
]
.into_iter()
.map(ListItem::new)
.collect::<Vec<ListItem>>();
let list = List::new(items);
let buffer = render_widget(list, 6, 5);
let expected = Buffer::with_lines(vec!["Odd ", " Even ", " Width", " ", " "]);
assert_buffer_eq!(buffer, expected);
}
#[test]
fn test_render_list_alignment_zero_line_width() {
let items = [Line::from("This line has zero width").alignment(Alignment::Center)]
.into_iter()
.map(ListItem::new)
.collect::<Vec<ListItem>>();
let list = List::new(items);
let buffer = render_widget(list, 0, 5);
let expected = Buffer::with_lines(vec!["", "", "", "", ""]);
assert_buffer_eq!(buffer, expected);
}
#[test]
fn test_render_list_alignment_zero_area_width() {
let items = [Line::from("Text").alignment(Alignment::Left)]
.into_iter()
.map(ListItem::new)
.collect::<Vec<ListItem>>();
let list = List::new(items);
// assert_buffer_eq! doesn't handle zero height buffers so we call this test manually
// rather than using render_widget
let mut buffer = Buffer::empty(Rect::new(0, 0, 4, 1));
Widget::render(list, Rect::new(0, 0, 4, 0), &mut buffer);
let expected = Buffer::with_lines(vec![" "]);
assert_buffer_eq!(buffer, expected);
}
#[test]
fn test_render_list_alignment_line_less_than_width() {
let items = [Line::from("Small").alignment(Alignment::Center)]
.into_iter()
.map(ListItem::new)
.collect::<Vec<ListItem>>();
let list = List::new(items);
let buffer = render_widget(list, 10, 5);
let expected = Buffer::with_lines(vec![
" Small ",
" ",
" ",
" ",
" ",
]);
assert_buffer_eq!(buffer, expected);
}
#[test]
fn test_render_list_alignment_line_equal_to_width() {
let items = [Line::from("Exact").alignment(Alignment::Left)]
.into_iter()
.map(ListItem::new)
.collect::<Vec<ListItem>>();
let list = List::new(items);
let buffer = render_widget(list, 5, 3);
let expected = Buffer::with_lines(vec!["Exact", " ", " "]);
assert_buffer_eq!(buffer, expected);
}
#[test]
fn test_render_list_alignment_line_greater_than_width() {
let items = [Line::from("Large line").alignment(Alignment::Left)]
.into_iter()
.map(ListItem::new)
.collect::<Vec<ListItem>>();
let list = List::new(items);
let buffer = render_widget(list, 5, 3);
let expected = Buffer::with_lines(vec!["Large", " ", " "]);
assert_buffer_eq!(buffer, expected);
}
}