use std::{
fmt,
io::{self, Write},
};
use crossterm::{
execute, queue, terminal, Clear, ClearType, Crossterm, ErrorKind, Goto, Hide, SetAttr, SetBg,
SetFg, Show,
};
use crate::{
backend::Backend,
buffer::Cell,
layout::Rect,
style::{Color, Modifier, Style},
};
pub struct CrosstermBackend<W: Write> {
alternate_screen: Option<crossterm::AlternateScreen>,
stdout: W,
}
impl<W> CrosstermBackend<W>
where
W: Write,
{
pub fn new(stdout: W) -> CrosstermBackend<W> {
CrosstermBackend {
alternate_screen: None,
stdout,
}
}
pub fn with_alternate_screen(
stdout: W,
alternate_screen: crossterm::AlternateScreen,
) -> Result<CrosstermBackend<W>, io::Error> {
Ok(CrosstermBackend {
alternate_screen: Some(alternate_screen),
stdout,
})
}
pub fn alternate_screen(&self) -> Option<&crossterm::AlternateScreen> {
match &self.alternate_screen {
Some(alt_screen) => Some(&alt_screen),
None => None,
}
}
pub fn crossterm(&self) -> crossterm::Crossterm {
Crossterm::new()
}
}
fn convert_error(error: ErrorKind) -> io::Error {
match error {
ErrorKind::IoError(err) => err,
ErrorKind::FmtError(err) => {
io::Error::new(io::ErrorKind::Other, format!("Invalid formatting: {}", err))
}
ErrorKind::ResizingTerminalFailure(err) => io::Error::new(
io::ErrorKind::Other,
format!("Failed to resize terminal: {}", err),
),
_ => io::Error::new(io::ErrorKind::Other, "Unknown crossterm error"),
}
}
impl<W> Write for CrosstermBackend<W>
where
W: Write,
{
fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
self.stdout.write(buf)
}
fn flush(&mut self) -> io::Result<()> {
self.stdout.flush()
}
}
impl<W> Backend for CrosstermBackend<W>
where
W: Write,
{
fn clear(&mut self) -> io::Result<()> {
execute!(self.stdout, Clear(ClearType::All)).map_err(convert_error)
}
fn hide_cursor(&mut self) -> io::Result<()> {
execute!(self.stdout, Hide).map_err(convert_error)
}
fn show_cursor(&mut self) -> io::Result<()> {
execute!(self.stdout, Show).map_err(convert_error)
}
fn get_cursor(&mut self) -> io::Result<(u16, u16)> {
let cursor = crossterm::cursor();
Ok(cursor.pos())
}
fn set_cursor(&mut self, x: u16, y: u16) -> io::Result<()> {
execute!(self.stdout, Goto(x, y)).map_err(convert_error)
}
fn size(&self) -> io::Result<Rect> {
let terminal = terminal();
let (width, height) = terminal.terminal_size(); Ok(Rect::new(0, 0, width, height))
}
fn flush(&mut self) -> io::Result<()> {
self.stdout.flush()
}
fn draw<'a, I>(&mut self, content: I) -> io::Result<()>
where
I: Iterator<Item = (u16, u16, &'a Cell)>,
{
use std::fmt::Write;
let mut string = String::with_capacity(content.size_hint().0 * 3);
let mut style = Style::default();
let mut last_y = 0;
let mut last_x = 0;
let mut inst = 0;
for (x, y, cell) in content {
if y != last_y || x != last_x + 1 || inst == 0 {
queue!(string, Goto(x, y)).unwrap();
}
last_x = x;
last_y = y;
if cell.style.modifier != style.modifier {
let diff = ModifierDiff {
from: style.modifier,
to: cell.style.modifier,
};
diff.queue(&mut string)?;
inst += 1;
style.modifier = cell.style.modifier;
}
if cell.style.fg != style.fg {
let color = to_crossterm_color(cell.style.fg);
queue!(string, SetFg(color))?;
style.fg = cell.style.fg;
inst += 1;
}
if cell.style.bg != style.bg {
let color = to_crossterm_color(cell.style.bg);
queue!(string, SetBg(color))?;
style.bg = cell.style.bg;
inst += 1;
}
string.push_str(&cell.symbol);
inst += 1;
}
write!(
self.stdout,
"{}{}{}{}",
string,
SetFg(crossterm::Color::Reset),
SetBg(crossterm::Color::Reset),
SetAttr(crossterm::Attribute::Reset)
)?;
Crossterm::new().color().reset()?;
Ok(())
}
}
#[derive(Debug)]
struct ModifierDiff {
pub from: Modifier,
pub to: Modifier,
}
#[cfg(unix)]
impl ModifierDiff {
fn queue<W>(&self, mut w: W) -> io::Result<()>
where
W: fmt::Write,
{
use crossterm::Attribute;
let removed = self.from - self.to;
if removed.contains(Modifier::REVERSED) {
queue!(w, SetAttr(Attribute::NoInverse))?;
}
if removed.contains(Modifier::BOLD) {
queue!(w, SetAttr(Attribute::NormalIntensity))?;
if self.to.contains(Modifier::DIM) {
queue!(w, SetAttr(Attribute::Dim))?;
}
}
if removed.contains(Modifier::ITALIC) {
queue!(w, SetAttr(Attribute::NoItalic))?;
}
if removed.contains(Modifier::UNDERLINED) {
queue!(w, SetAttr(Attribute::NoUnderline))?;
}
if removed.contains(Modifier::DIM) {
queue!(w, SetAttr(Attribute::NormalIntensity))?;
}
if removed.contains(Modifier::CROSSED_OUT) {
queue!(w, SetAttr(Attribute::NotCrossedOut))?;
}
if removed.contains(Modifier::SLOW_BLINK) || removed.contains(Modifier::RAPID_BLINK) {
queue!(w, SetAttr(Attribute::NoBlink))?;
}
let added = self.to - self.from;
if added.contains(Modifier::REVERSED) {
queue!(w, SetAttr(Attribute::Reverse))?;
}
if added.contains(Modifier::BOLD) {
queue!(w, SetAttr(Attribute::Bold))?;
}
if added.contains(Modifier::ITALIC) {
queue!(w, SetAttr(Attribute::Italic))?;
}
if added.contains(Modifier::UNDERLINED) {
queue!(w, SetAttr(Attribute::Underlined))?;
}
if added.contains(Modifier::DIM) {
queue!(w, SetAttr(Attribute::Dim))?;
}
if added.contains(Modifier::CROSSED_OUT) {
queue!(w, SetAttr(Attribute::CrossedOut))?;
}
if added.contains(Modifier::SLOW_BLINK) {
queue!(w, SetAttr(Attribute::SlowBlink))?;
}
if added.contains(Modifier::RAPID_BLINK) {
queue!(w, SetAttr(Attribute::RapidBlink))?;
}
Ok(())
}
}
#[cfg(windows)]
impl ModifierDiff {
fn queue<W>(&self, mut w: W) -> io::Result<()>
where
W: fmt::Write,
{
use crossterm::Attribute;
let removed = self.from - self.to;
if removed.contains(Modifier::BOLD) {
queue!(w, SetAttr(Attribute::NormalIntensity))?;
}
if removed.contains(Modifier::UNDERLINED) {
queue!(w, SetAttr(Attribute::NoUnderline))?;
}
let added = self.to - self.from;
if added.contains(Modifier::BOLD) {
queue!(w, SetAttr(Attribute::Bold))?;
}
if added.contains(Modifier::UNDERLINED) {
queue!(w, SetAttr(Attribute::Underlined))?;
}
Ok(())
}
}
fn to_crossterm_color(color: Color) -> crossterm::Color {
match color {
Color::Reset => crossterm::Color::Reset,
Color::Black => crossterm::Color::Black,
Color::Red => crossterm::Color::DarkRed,
Color::Green => crossterm::Color::DarkGreen,
Color::Yellow => crossterm::Color::DarkYellow,
Color::Blue => crossterm::Color::DarkBlue,
Color::Magenta => crossterm::Color::DarkMagenta,
Color::Cyan => crossterm::Color::DarkCyan,
Color::Gray => crossterm::Color::Grey,
Color::DarkGray => crossterm::Color::DarkGrey,
Color::LightRed => crossterm::Color::Red,
Color::LightGreen => crossterm::Color::Green,
Color::LightBlue => crossterm::Color::Blue,
Color::LightYellow => crossterm::Color::Yellow,
Color::LightMagenta => crossterm::Color::Magenta,
Color::LightCyan => crossterm::Color::Cyan,
Color::White => crossterm::Color::White,
Color::Indexed(i) => crossterm::Color::AnsiValue(i),
Color::Rgb(r, g, b) => crossterm::Color::Rgb { r, g, b },
}
}