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use std::fmt;
use unicode_segmentation::UnicodeSegmentation;
use unicode_width::UnicodeWidthStr;
use crate::{buffer::Cell, prelude::*};
/// A buffer that maps to the desired content of the terminal after the draw call
///
/// No widget in the library interacts directly with the terminal. Instead each of them is required
/// to draw their state to an intermediate buffer. It is basically a grid where each cell contains
/// a grapheme, a foreground color and a background color. This grid will then be used to output
/// the appropriate escape sequences and characters to draw the UI as the user has defined it.
///
/// # Examples:
///
/// ```
/// use ratatui::{buffer::Cell, prelude::*};
///
/// let mut buf = Buffer::empty(Rect {
/// x: 0,
/// y: 0,
/// width: 10,
/// height: 5,
/// });
/// buf.get_mut(0, 2).set_symbol("x");
/// assert_eq!(buf.get(0, 2).symbol(), "x");
///
/// buf.set_string(
/// 3,
/// 0,
/// "string",
/// Style::default().fg(Color::Red).bg(Color::White),
/// );
/// let cell = buf.get(5, 0);
/// assert_eq!(cell.symbol(), "r");
/// assert_eq!(cell.fg, Color::Red);
/// assert_eq!(cell.bg, Color::White);
///
/// buf.get_mut(5, 0).set_char('x');
/// assert_eq!(buf.get(5, 0).symbol(), "x");
/// ```
#[derive(Default, Clone, Eq, PartialEq, Hash)]
#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
pub struct Buffer {
/// The area represented by this buffer
pub area: Rect,
/// The content of the buffer. The length of this Vec should always be equal to area.width *
/// area.height
pub content: Vec<Cell>,
}
impl Buffer {
/// Returns a Buffer with all cells set to the default one
#[must_use]
pub fn empty(area: Rect) -> Self {
Self::filled(area, &Cell::default())
}
/// Returns a Buffer with all cells initialized with the attributes of the given Cell
#[must_use]
pub fn filled(area: Rect, cell: &Cell) -> Self {
let size = area.area() as usize;
let content = vec![cell.clone(); size];
Self { area, content }
}
/// Returns a Buffer containing the given lines
#[must_use]
pub fn with_lines<'a, Iter>(lines: Iter) -> Self
where
Iter: IntoIterator,
Iter::Item: Into<Line<'a>>,
{
let lines = lines.into_iter().map(Into::into).collect::<Vec<_>>();
let height = lines.len() as u16;
let width = lines.iter().map(Line::width).max().unwrap_or_default() as u16;
let mut buffer = Self::empty(Rect::new(0, 0, width, height));
for (y, line) in lines.iter().enumerate() {
buffer.set_line(0, y as u16, line, width);
}
buffer
}
/// Returns the content of the buffer as a slice
pub fn content(&self) -> &[Cell] {
&self.content
}
/// Returns the area covered by this buffer
pub const fn area(&self) -> &Rect {
&self.area
}
/// Returns a reference to Cell at the given coordinates
#[track_caller]
pub fn get(&self, x: u16, y: u16) -> &Cell {
let i = self.index_of(x, y);
&self.content[i]
}
/// Returns a mutable reference to Cell at the given coordinates
#[track_caller]
pub fn get_mut(&mut self, x: u16, y: u16) -> &mut Cell {
let i = self.index_of(x, y);
&mut self.content[i]
}
/// Returns the index in the `Vec<Cell>` for the given global (x, y) coordinates.
///
/// Global coordinates are offset by the Buffer's area offset (`x`/`y`).
///
/// # Examples
///
/// ```
/// # use ratatui::prelude::*;
/// let rect = Rect::new(200, 100, 10, 10);
/// let buffer = Buffer::empty(rect);
/// // Global coordinates to the top corner of this buffer's area
/// assert_eq!(buffer.index_of(200, 100), 0);
/// ```
///
/// # Panics
///
/// Panics when given an coordinate that is outside of this Buffer's area.
///
/// ```should_panic
/// # use ratatui::prelude::*;
/// let rect = Rect::new(200, 100, 10, 10);
/// let buffer = Buffer::empty(rect);
/// // Top coordinate is outside of the buffer in global coordinate space, as the Buffer's area
/// // starts at (200, 100).
/// buffer.index_of(0, 0); // Panics
/// ```
#[track_caller]
pub fn index_of(&self, x: u16, y: u16) -> usize {
debug_assert!(
x >= self.area.left()
&& x < self.area.right()
&& y >= self.area.top()
&& y < self.area.bottom(),
"Trying to access position outside the buffer: x={x}, y={y}, area={:?}",
self.area
);
((y - self.area.y) * self.area.width + (x - self.area.x)) as usize
}
/// Returns the (global) coordinates of a cell given its index
///
/// Global coordinates are offset by the Buffer's area offset (`x`/`y`).
///
/// # Examples
///
/// ```
/// # use ratatui::prelude::*;
/// let rect = Rect::new(200, 100, 10, 10);
/// let buffer = Buffer::empty(rect);
/// assert_eq!(buffer.pos_of(0), (200, 100));
/// assert_eq!(buffer.pos_of(14), (204, 101));
/// ```
///
/// # Panics
///
/// Panics when given an index that is outside the Buffer's content.
///
/// ```should_panic
/// # use ratatui::prelude::*;
/// let rect = Rect::new(0, 0, 10, 10); // 100 cells in total
/// let buffer = Buffer::empty(rect);
/// // Index 100 is the 101th cell, which lies outside of the area of this Buffer.
/// buffer.pos_of(100); // Panics
/// ```
pub fn pos_of(&self, i: usize) -> (u16, u16) {
debug_assert!(
i < self.content.len(),
"Trying to get the coords of a cell outside the buffer: i={i} len={}",
self.content.len()
);
(
self.area.x + (i as u16) % self.area.width,
self.area.y + (i as u16) / self.area.width,
)
}
/// Print a string, starting at the position (x, y)
pub fn set_string<T, S>(&mut self, x: u16, y: u16, string: T, style: S)
where
T: AsRef<str>,
S: Into<Style>,
{
self.set_stringn(x, y, string, usize::MAX, style);
}
/// Print at most the first n characters of a string if enough space is available
/// until the end of the line.
///
/// Use [`Buffer::set_string`] when the maximum amount of characters can be printed.
pub fn set_stringn<T, S>(
&mut self,
mut x: u16,
y: u16,
string: T,
max_width: usize,
style: S,
) -> (u16, u16)
where
T: AsRef<str>,
S: Into<Style>,
{
let max_width = max_width.try_into().unwrap_or(u16::MAX);
let mut remaining_width = self.area.right().saturating_sub(x).min(max_width);
let graphemes = UnicodeSegmentation::graphemes(string.as_ref(), true)
.map(|symbol| (symbol, symbol.width() as u16))
.filter(|(_symbol, width)| *width > 0)
.map_while(|(symbol, width)| {
remaining_width = remaining_width.checked_sub(width)?;
Some((symbol, width))
});
let style = style.into();
for (symbol, width) in graphemes {
self.get_mut(x, y).set_symbol(symbol).set_style(style);
let next_symbol = x + width;
x += 1;
// Reset following cells if multi-width (they would be hidden by the grapheme),
while x < next_symbol {
self.get_mut(x, y).reset();
x += 1;
}
}
(x, y)
}
/// Print a line, starting at the position (x, y)
pub fn set_line(&mut self, x: u16, y: u16, line: &Line<'_>, max_width: u16) -> (u16, u16) {
let mut remaining_width = max_width;
let mut x = x;
for span in line {
if remaining_width == 0 {
break;
}
let pos = self.set_stringn(
x,
y,
span.content.as_ref(),
remaining_width as usize,
line.style.patch(span.style),
);
let w = pos.0.saturating_sub(x);
x = pos.0;
remaining_width = remaining_width.saturating_sub(w);
}
(x, y)
}
/// Print a span, starting at the position (x, y)
pub fn set_span(&mut self, x: u16, y: u16, span: &Span<'_>, max_width: u16) -> (u16, u16) {
self.set_stringn(x, y, &span.content, max_width as usize, span.style)
}
/// Set the style of all cells in the given area.
///
/// `style` accepts any type that is convertible to [`Style`] (e.g. [`Style`], [`Color`], or
/// your own type that implements [`Into<Style>`]).
pub fn set_style<S: Into<Style>>(&mut self, area: Rect, style: S) {
let style = style.into();
let area = self.area.intersection(area);
for y in area.top()..area.bottom() {
for x in area.left()..area.right() {
self.get_mut(x, y).set_style(style);
}
}
}
/// Resize the buffer so that the mapped area matches the given area and that the buffer
/// length is equal to area.width * area.height
pub fn resize(&mut self, area: Rect) {
let length = area.area() as usize;
if self.content.len() > length {
self.content.truncate(length);
} else {
self.content.resize(length, Cell::default());
}
self.area = area;
}
/// Reset all cells in the buffer
pub fn reset(&mut self) {
for c in &mut self.content {
c.reset();
}
}
/// Merge an other buffer into this one
pub fn merge(&mut self, other: &Self) {
let area = self.area.union(other.area);
self.content.resize(area.area() as usize, Cell::default());
// Move original content to the appropriate space
let size = self.area.area() as usize;
for i in (0..size).rev() {
let (x, y) = self.pos_of(i);
// New index in content
let k = ((y - area.y) * area.width + x - area.x) as usize;
if i != k {
self.content[k] = self.content[i].clone();
self.content[i] = Cell::default();
}
}
// Push content of the other buffer into this one (may erase previous
// data)
let size = other.area.area() as usize;
for i in 0..size {
let (x, y) = other.pos_of(i);
// New index in content
let k = ((y - area.y) * area.width + x - area.x) as usize;
self.content[k] = other.content[i].clone();
}
self.area = area;
}
/// Builds a minimal sequence of coordinates and Cells necessary to update the UI from
/// self to other.
///
/// We're assuming that buffers are well-formed, that is no double-width cell is followed by
/// a non-blank cell.
///
/// # Multi-width characters handling:
///
/// ```text
/// (Index:) `01`
/// Prev: `コ`
/// Next: `aa`
/// Updates: `0: a, 1: a'
/// ```
///
/// ```text
/// (Index:) `01`
/// Prev: `a `
/// Next: `コ`
/// Updates: `0: コ` (double width symbol at index 0 - skip index 1)
/// ```
///
/// ```text
/// (Index:) `012`
/// Prev: `aaa`
/// Next: `aコ`
/// Updates: `0: a, 1: コ` (double width symbol at index 1 - skip index 2)
/// ```
pub fn diff<'a>(&self, other: &'a Self) -> Vec<(u16, u16, &'a Cell)> {
let previous_buffer = &self.content;
let next_buffer = &other.content;
let mut updates: Vec<(u16, u16, &Cell)> = vec![];
// Cells invalidated by drawing/replacing preceding multi-width characters:
let mut invalidated: usize = 0;
// Cells from the current buffer to skip due to preceding multi-width characters taking
// their place (the skipped cells should be blank anyway), or due to per-cell-skipping:
let mut to_skip: usize = 0;
for (i, (current, previous)) in next_buffer.iter().zip(previous_buffer.iter()).enumerate() {
if !current.skip && (current != previous || invalidated > 0) && to_skip == 0 {
let (x, y) = self.pos_of(i);
updates.push((x, y, &next_buffer[i]));
}
to_skip = current.symbol().width().saturating_sub(1);
let affected_width = std::cmp::max(current.symbol().width(), previous.symbol().width());
invalidated = std::cmp::max(affected_width, invalidated).saturating_sub(1);
}
updates
}
}
impl fmt::Debug for Buffer {
/// Writes a debug representation of the buffer to the given formatter.
///
/// The format is like a pretty printed struct, with the following fields:
/// * `area`: displayed as `Rect { x: 1, y: 2, width: 3, height: 4 }`
/// * `content`: displayed as a list of strings representing the content of the buffer
/// * `styles`: displayed as a list of: `{ x: 1, y: 2, fg: Color::Red, bg: Color::Blue,
/// modifier: Modifier::BOLD }` only showing a value when there is a change in style.
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
f.write_fmt(format_args!("Buffer {{\n area: {:?}", &self.area))?;
if self.area.is_empty() {
return f.write_str("\n}");
}
f.write_str(",\n content: [\n")?;
let mut last_style = None;
let mut styles = vec![];
for (y, line) in self.content.chunks(self.area.width as usize).enumerate() {
let mut overwritten = vec![];
let mut skip: usize = 0;
f.write_str(" \"")?;
for (x, c) in line.iter().enumerate() {
if skip == 0 {
f.write_str(c.symbol())?;
} else {
overwritten.push((x, c.symbol()));
}
skip = std::cmp::max(skip, c.symbol().width()).saturating_sub(1);
#[cfg(feature = "underline-color")]
{
let style = (c.fg, c.bg, c.underline_color, c.modifier);
if last_style != Some(style) {
last_style = Some(style);
styles.push((x, y, c.fg, c.bg, c.underline_color, c.modifier));
}
}
#[cfg(not(feature = "underline-color"))]
{
let style = (c.fg, c.bg, c.modifier);
if last_style != Some(style) {
last_style = Some(style);
styles.push((x, y, c.fg, c.bg, c.modifier));
}
}
}
f.write_str("\",")?;
if !overwritten.is_empty() {
f.write_fmt(format_args!(
" // hidden by multi-width symbols: {overwritten:?}"
))?;
}
f.write_str("\n")?;
}
f.write_str(" ],\n styles: [\n")?;
for s in styles {
#[cfg(feature = "underline-color")]
f.write_fmt(format_args!(
" x: {}, y: {}, fg: {:?}, bg: {:?}, underline: {:?}, modifier: {:?},\n",
s.0, s.1, s.2, s.3, s.4, s.5
))?;
#[cfg(not(feature = "underline-color"))]
f.write_fmt(format_args!(
" x: {}, y: {}, fg: {:?}, bg: {:?}, modifier: {:?},\n",
s.0, s.1, s.2, s.3, s.4
))?;
}
f.write_str(" ]\n}")?;
Ok(())
}
}
#[cfg(test)]
mod tests {
use std::iter;
use itertools::Itertools;
use rstest::{fixture, rstest};
use super::*;
fn cell(s: &str) -> Cell {
let mut cell = Cell::default();
cell.set_symbol(s);
cell
}
#[test]
fn debug_empty_buffer() {
let buffer = Buffer::empty(Rect::ZERO);
let result = format!("{buffer:?}");
println!("{result}");
let expected = "Buffer {\n area: Rect { x: 0, y: 0, width: 0, height: 0 }\n}";
assert_eq!(result, expected);
}
#[cfg(feature = "underline-color")]
#[test]
fn debug_grapheme_override() {
let buffer = Buffer::with_lines(["a🦀b"]);
let result = format!("{buffer:?}");
println!("{result}");
let expected = indoc::indoc!(
r#"
Buffer {
area: Rect { x: 0, y: 0, width: 4, height: 1 },
content: [
"a🦀b", // hidden by multi-width symbols: [(2, " ")]
],
styles: [
x: 0, y: 0, fg: Reset, bg: Reset, underline: Reset, modifier: NONE,
]
}"#
);
assert_eq!(result, expected);
}
#[test]
fn debug_some_example() {
let mut buffer = Buffer::empty(Rect::new(0, 0, 12, 2));
buffer.set_string(0, 0, "Hello World!", Style::default());
buffer.set_string(
0,
1,
"G'day World!",
Style::default()
.fg(Color::Green)
.bg(Color::Yellow)
.add_modifier(Modifier::BOLD),
);
let result = format!("{buffer:?}");
println!("{result}");
#[cfg(feature = "underline-color")]
let expected = indoc::indoc!(
r#"
Buffer {
area: Rect { x: 0, y: 0, width: 12, height: 2 },
content: [
"Hello World!",
"G'day World!",
],
styles: [
x: 0, y: 0, fg: Reset, bg: Reset, underline: Reset, modifier: NONE,
x: 0, y: 1, fg: Green, bg: Yellow, underline: Reset, modifier: BOLD,
]
}"#
);
#[cfg(not(feature = "underline-color"))]
let expected = indoc::indoc!(
r#"
Buffer {
area: Rect { x: 0, y: 0, width: 12, height: 2 },
content: [
"Hello World!",
"G'day World!",
],
styles: [
x: 0, y: 0, fg: Reset, bg: Reset, modifier: NONE,
x: 0, y: 1, fg: Green, bg: Yellow, modifier: BOLD,
]
}"#
);
assert_eq!(result, expected);
}
#[test]
fn it_translates_to_and_from_coordinates() {
let rect = Rect::new(200, 100, 50, 80);
let buf = Buffer::empty(rect);
// First cell is at the upper left corner.
assert_eq!(buf.pos_of(0), (200, 100));
assert_eq!(buf.index_of(200, 100), 0);
// Last cell is in the lower right.
assert_eq!(buf.pos_of(buf.content.len() - 1), (249, 179));
assert_eq!(buf.index_of(249, 179), buf.content.len() - 1);
}
#[test]
#[should_panic(expected = "outside the buffer")]
fn pos_of_panics_on_out_of_bounds() {
let rect = Rect::new(0, 0, 10, 10);
let buf = Buffer::empty(rect);
// There are a total of 100 cells; zero-indexed means that 100 would be the 101st cell.
buf.pos_of(100);
}
#[test]
#[should_panic(expected = "outside the buffer")]
fn index_of_panics_on_out_of_bounds() {
let rect = Rect::new(0, 0, 10, 10);
let buf = Buffer::empty(rect);
// width is 10; zero-indexed means that 10 would be the 11th cell.
buf.index_of(10, 0);
}
#[test]
fn set_string() {
let area = Rect::new(0, 0, 5, 1);
let mut buffer = Buffer::empty(area);
// Zero-width
buffer.set_stringn(0, 0, "aaa", 0, Style::default());
assert_eq!(buffer, Buffer::with_lines([" "]));
buffer.set_string(0, 0, "aaa", Style::default());
assert_eq!(buffer, Buffer::with_lines(["aaa "]));
// Width limit:
buffer.set_stringn(0, 0, "bbbbbbbbbbbbbb", 4, Style::default());
assert_eq!(buffer, Buffer::with_lines(["bbbb "]));
buffer.set_string(0, 0, "12345", Style::default());
assert_eq!(buffer, Buffer::with_lines(["12345"]));
// Width truncation:
buffer.set_string(0, 0, "123456", Style::default());
assert_eq!(buffer, Buffer::with_lines(["12345"]));
// multi-line
buffer = Buffer::empty(Rect::new(0, 0, 5, 2));
buffer.set_string(0, 0, "12345", Style::default());
buffer.set_string(0, 1, "67890", Style::default());
assert_eq!(buffer, Buffer::with_lines(["12345", "67890"]));
}
#[test]
fn set_string_multi_width_overwrite() {
let area = Rect::new(0, 0, 5, 1);
let mut buffer = Buffer::empty(area);
// multi-width overwrite
buffer.set_string(0, 0, "aaaaa", Style::default());
buffer.set_string(0, 0, "称号", Style::default());
assert_eq!(buffer, Buffer::with_lines(["称号a"]));
}
#[test]
fn set_string_zero_width() {
let area = Rect::new(0, 0, 1, 1);
let mut buffer = Buffer::empty(area);
// Leading grapheme with zero width
let s = "\u{1}a";
buffer.set_stringn(0, 0, s, 1, Style::default());
assert_eq!(buffer, Buffer::with_lines(["a"]));
// Trailing grapheme with zero with
let s = "a\u{1}";
buffer.set_stringn(0, 0, s, 1, Style::default());
assert_eq!(buffer, Buffer::with_lines(["a"]));
}
#[test]
fn set_string_double_width() {
let area = Rect::new(0, 0, 5, 1);
let mut buffer = Buffer::empty(area);
buffer.set_string(0, 0, "コン", Style::default());
assert_eq!(buffer, Buffer::with_lines(["コン "]));
// Only 1 space left.
buffer.set_string(0, 0, "コンピ", Style::default());
assert_eq!(buffer, Buffer::with_lines(["コン "]));
}
#[fixture]
fn small_one_line_buffer() -> Buffer {
Buffer::empty(Rect::new(0, 0, 5, 1))
}
#[rstest]
#[case::empty("", " ")]
#[case::one("1", "1 ")]
#[case::full("12345", "12345")]
#[case::overflow("123456", "12345")]
fn set_line_raw(
mut small_one_line_buffer: Buffer,
#[case] content: &str,
#[case] expected: &str,
) {
let line = Line::raw(content);
small_one_line_buffer.set_line(0, 0, &line, 5);
// note: testing with empty / set_string here instead of with_lines because with_lines calls
// set_line
let mut expected_buffer = Buffer::empty(small_one_line_buffer.area);
expected_buffer.set_string(0, 0, expected, Style::default());
assert_eq!(small_one_line_buffer, expected_buffer);
}
#[rstest]
#[case::empty("", " ")]
#[case::one("1", "1 ")]
#[case::full("12345", "12345")]
#[case::overflow("123456", "12345")]
fn set_line_styled(
mut small_one_line_buffer: Buffer,
#[case] content: &str,
#[case] expected: &str,
) {
let color = Color::Blue;
let line = Line::styled(content, color);
small_one_line_buffer.set_line(0, 0, &line, 5);
// note: manually testing the contents here as the Buffer::with_lines calls set_line
let actual_contents = small_one_line_buffer
.content
.iter()
.map(Cell::symbol)
.join("");
let actual_styles = small_one_line_buffer
.content
.iter()
.map(|c| c.fg)
.collect_vec();
// set_line only sets the style for non-empty cells (unlike Line::render which sets the
// style for all cells)
let expected_styles = iter::repeat(color)
.take(content.len().min(5))
.chain(iter::repeat(Color::default()).take(5_usize.saturating_sub(content.len())))
.collect_vec();
assert_eq!(actual_contents, expected);
assert_eq!(actual_styles, expected_styles);
}
#[test]
fn set_style() {
let mut buffer = Buffer::with_lines(["aaaaa", "bbbbb", "ccccc"]);
buffer.set_style(Rect::new(0, 1, 5, 1), Style::new().red());
#[rustfmt::skip]
let expected = Buffer::with_lines([
"aaaaa".into(),
"bbbbb".red(),
"ccccc".into(),
]);
assert_eq!(buffer, expected);
}
#[test]
fn set_style_does_not_panic_when_out_of_area() {
let mut buffer = Buffer::with_lines(["aaaaa", "bbbbb", "ccccc"]);
buffer.set_style(Rect::new(0, 1, 10, 3), Style::new().red());
#[rustfmt::skip]
let expected = Buffer::with_lines([
"aaaaa".into(),
"bbbbb".red(),
"ccccc".red(),
]);
assert_eq!(buffer, expected);
}
#[test]
fn with_lines() {
#[rustfmt::skip]
let buffer = Buffer::with_lines([
"┌────────┐",
"│コンピュ│",
"│ーa 上で│",
"└────────┘",
]);
assert_eq!(buffer.area.x, 0);
assert_eq!(buffer.area.y, 0);
assert_eq!(buffer.area.width, 10);
assert_eq!(buffer.area.height, 4);
}
#[test]
fn diff_empty_empty() {
let area = Rect::new(0, 0, 40, 40);
let prev = Buffer::empty(area);
let next = Buffer::empty(area);
let diff = prev.diff(&next);
assert_eq!(diff, vec![]);
}
#[test]
fn diff_empty_filled() {
let area = Rect::new(0, 0, 40, 40);
let prev = Buffer::empty(area);
let next = Buffer::filled(area, Cell::default().set_symbol("a"));
let diff = prev.diff(&next);
assert_eq!(diff.len(), 40 * 40);
}
#[test]
fn diff_filled_filled() {
let area = Rect::new(0, 0, 40, 40);
let prev = Buffer::filled(area, Cell::default().set_symbol("a"));
let next = Buffer::filled(area, Cell::default().set_symbol("a"));
let diff = prev.diff(&next);
assert_eq!(diff, vec![]);
}
#[test]
fn diff_single_width() {
let prev = Buffer::with_lines([
" ",
"┌Title─┐ ",
"│ │ ",
"│ │ ",
"└──────┘ ",
]);
let next = Buffer::with_lines([
" ",
"┌TITLE─┐ ",
"│ │ ",
"│ │ ",
"└──────┘ ",
]);
let diff = prev.diff(&next);
assert_eq!(
diff,
vec![
(2, 1, &cell("I")),
(3, 1, &cell("T")),
(4, 1, &cell("L")),
(5, 1, &cell("E")),
]
);
}
#[test]
#[rustfmt::skip]
fn diff_multi_width() {
let prev = Buffer::with_lines([
"┌Title─┐ ",
"└──────┘ ",
]);
let next = Buffer::with_lines([
"┌称号──┐ ",
"└──────┘ ",
]);
let diff = prev.diff(&next);
assert_eq!(
diff,
vec![
(1, 0, &cell("称")),
// Skipped "i"
(3, 0, &cell("号")),
// Skipped "l"
(5, 0, &cell("─")),
]
);
}
#[test]
fn diff_multi_width_offset() {
let prev = Buffer::with_lines(["┌称号──┐"]);
let next = Buffer::with_lines(["┌─称号─┐"]);
let diff = prev.diff(&next);
assert_eq!(
diff,
vec![(1, 0, &cell("─")), (2, 0, &cell("称")), (4, 0, &cell("号")),]
);
}
#[test]
fn diff_skip() {
let prev = Buffer::with_lines(["123"]);
let mut next = Buffer::with_lines(["456"]);
for i in 1..3 {
next.content[i].set_skip(true);
}
let diff = prev.diff(&next);
assert_eq!(diff, vec![(0, 0, &cell("4"))],);
}
#[test]
fn merge() {
let mut one = Buffer::filled(
Rect {
x: 0,
y: 0,
width: 2,
height: 2,
},
Cell::default().set_symbol("1"),
);
let two = Buffer::filled(
Rect {
x: 0,
y: 2,
width: 2,
height: 2,
},
Cell::default().set_symbol("2"),
);
one.merge(&two);
assert_eq!(one, Buffer::with_lines(["11", "11", "22", "22"]));
}
#[test]
fn merge2() {
let mut one = Buffer::filled(
Rect {
x: 2,
y: 2,
width: 2,
height: 2,
},
Cell::default().set_symbol("1"),
);
let two = Buffer::filled(
Rect {
x: 0,
y: 0,
width: 2,
height: 2,
},
Cell::default().set_symbol("2"),
);
one.merge(&two);
assert_eq!(one, Buffer::with_lines(["22 ", "22 ", " 11", " 11"]));
}
#[test]
fn merge3() {
let mut one = Buffer::filled(
Rect {
x: 3,
y: 3,
width: 2,
height: 2,
},
Cell::default().set_symbol("1"),
);
let two = Buffer::filled(
Rect {
x: 1,
y: 1,
width: 3,
height: 4,
},
Cell::default().set_symbol("2"),
);
one.merge(&two);
let mut merged = Buffer::with_lines(["222 ", "222 ", "2221", "2221"]);
merged.area = Rect {
x: 1,
y: 1,
width: 4,
height: 4,
};
assert_eq!(one, merged);
}
#[test]
fn merge_skip() {
let mut one = Buffer::filled(
Rect {
x: 0,
y: 0,
width: 2,
height: 2,
},
Cell::default().set_symbol("1"),
);
let two = Buffer::filled(
Rect {
x: 0,
y: 1,
width: 2,
height: 2,
},
Cell::default().set_symbol("2").set_skip(true),
);
one.merge(&two);
let skipped: Vec<bool> = one.content().iter().map(|c| c.skip).collect();
assert_eq!(skipped, vec![false, false, true, true, true, true]);
}
#[test]
fn merge_skip2() {
let mut one = Buffer::filled(
Rect {
x: 0,
y: 0,
width: 2,
height: 2,
},
Cell::default().set_symbol("1").set_skip(true),
);
let two = Buffer::filled(
Rect {
x: 0,
y: 1,
width: 2,
height: 2,
},
Cell::default().set_symbol("2"),
);
one.merge(&two);
let skipped: Vec<bool> = one.content().iter().map(|c| c.skip).collect();
assert_eq!(skipped, vec![true, true, false, false, false, false]);
}
#[test]
fn with_lines_accepts_into_lines() {
use crate::style::Stylize;
let mut buf = Buffer::empty(Rect::new(0, 0, 3, 2));
buf.set_string(0, 0, "foo", Style::new().red());
buf.set_string(0, 1, "bar", Style::new().blue());
assert_eq!(buf, Buffer::with_lines(["foo".red(), "bar".blue()]));
}
}