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|
mod rope;
mod term;
use rope::Rope;
use std::ffi::{OsStr, OsString};
use std::io::{stdout, stdin, Write, Read};
use std::error::Error;
use std::path::Path;
use term::Key;
struct State {
buf: Rope,
row_start: usize,
cursor_row: usize,
cursor_col: usize,
line_offset: usize,
line_cols: usize,
}
fn parse_status_report(buf: &[u8]) -> Result<(usize, usize), Box<dyn Error>> {
let mut semicolon = 0;
for (i, &c) in buf.iter().enumerate() {
if c == b';' {
semicolon = i;
break;
}
}
if semicolon < 2 || semicolon == buf.len()-1 {
return Err(Box::from("invalid response"));
}
let row_str = std::str::from_utf8(&buf[2..semicolon])?;
let col_str = std::str::from_utf8(&buf[semicolon+1..buf.len()-1])?;
let row = row_str.parse::<usize>()?;
let col = col_str.parse::<usize>()?;
// Yuck... 1 indexing
return Ok((row-1, col-1));
}
impl State {
fn cursor_pos(&mut self) -> Result<(usize, usize), Box<dyn Error>> {
write!(stdout(), "\x1b[6n").map_err(|err| format!("cursor position: status report: {}", err))?;
stdout().flush().map_err(|err| format!("cursor position: status report: {}", err))?;
let mut buf = vec![0; 20];
let n = stdin().read(&mut buf).map_err(|err| format!("cursor position: read status report: {}", err))?;
buf.truncate(n);
let pos = parse_status_report(&buf).map_err(|_| format!("cursor position: invalid response: {}", String::from_utf8_lossy(&buf)))?;
return Ok(pos);
}
fn repaint_all(&mut self) -> Result<(), Box<dyn Error>> {
let size = term::size()?;
write!(stdout(), "\x1b[H\x1b[J")?;
for i in self.row_start..self.row_start+usize::from(size.ws_row) {
if i > 0 {
write!(stdout(), "\r\n")?;
}
if i > self.buf.lines() {
break;
}
let line = self.buf.line(i);
let max_len = line.char(usize::from(size.ws_col-1));
line.slice(0, max_len).print(&mut stdout())?;
if max_len < line.len() {
write!(stdout(), "\x1b[30m\x1b[47m>\x1b[m")?;
}
}
return Ok(());
}
fn repaint_line_full(&mut self) -> Result<(), Box<dyn Error>> {
let term_size = term::size()?;
write!(stdout(), "\x1b[{}H\x1b[K", self.cursor_row+1)?;
let mut line = self.buf.line(self.row_start+self.cursor_row);
let max_len = line.char(usize::from(term_size.ws_col-1));
let mut truncated = false;
if max_len < line.len() {
line = line.slice(0, max_len);
truncated = true;
}
line.print(&mut stdout())?;
let (_, col) = self.cursor_pos()?;
self.line_cols = col;
if self.cursor_col >= self.line_cols {
self.line_offset = line.len();
if truncated {
write!(stdout(), "\x1b[30m\x1b[47m>\x1b[m\x1b[{}G", self.cursor_col+1)?;
}
return Ok(());
}
let mut lo = line.char(self.cursor_col);
let mut hi = line.len();
// Binary search :D
while hi > lo {
let x = line.floor_char_boundary(lo + (hi - lo) / 2);
write!(stdout(), "\x1b[G")?;
line.slice(0, x).print(&mut stdout())?;
let (_, col) = self.cursor_pos()?;
if col <= self.cursor_col {
lo = line.ceil_char_boundary(x+1);
} else {
hi = x;
}
}
self.line_offset = line.floor_char_boundary(lo-1);
write!(stdout(), "\x1b[G")?;
line.print(&mut stdout())?;
if truncated {
write!(stdout(), "\x1b[30m\x1b[47m>\x1b[m")?;
}
write!(stdout(), "\x1b[{}G", self.cursor_col+1)?;
return Ok(());
}
fn up(&mut self) -> Result<(), Box<dyn Error>> {
if self.cursor_row == 0 && self.row_start == 0 {
return Ok(());
}
if self.cursor_row == 0 {
self.row_start -= 1;
self.repaint_all()?;
} else {
self.cursor_row -= 1;
}
return Ok(());
}
fn down(&mut self) -> Result<(), Box<dyn Error>> {
if self.row_start+self.cursor_row == self.buf.lines() {
return Ok(());
}
let size = term::size()?;
if self.cursor_row == usize::from(size.ws_row - 1) {
self.row_start += 1;
self.repaint_all()?;
} else {
self.cursor_row += 1;
}
return Ok(());
}
fn left(&mut self) -> Result<(), Box<dyn Error>> {
if self.cursor_col > self.line_cols {
self.cursor_col = self.line_cols;
}
if self.cursor_col == 0 && self.cursor_row == 0 {
return Ok(());
}
if self.cursor_col == 0 {
self.up()?;
self.repaint_line_full()?;
self.cursor_col = self.line_cols;
} else {
self.cursor_col -= 1;
}
return Ok(());
}
fn right(&mut self) -> Result<(), Box<dyn Error>> {
let size = term::size()?;
if self.cursor_col >= self.line_cols && self.cursor_row == usize::from(size.ws_row-1) {
return Ok(());
}
if self.cursor_col >= self.line_cols {
self.down()?;
self.cursor_col = 0;
} else {
self.cursor_col += 1;
}
return Ok(());
}
}
fn edit(file: &OsStr) -> Result<(), Box<dyn Error>> {
let _raw_handle = term::raw().map_err(|err| format!("cannot put terminal in raw mode: {}", err))?;
let r = Rope::open(Path::new(file))?;
let size = term::size()?;
let mut state = State{
buf: r,
row_start: 0,
cursor_row: 0,
cursor_col: 0,
line_offset: 0,
line_cols: 0,
};
let _ = state.repaint_all();
let _ = write!(stdout(), "\x1b[H");
let _ = stdout().flush();
loop {
let c = term::read_key(&mut stdin()).map_err(|err| format!("read key: {}", err))?;
match c {
Key::CtrlQ => {
break;
}
Key::CtrlS => {
let _ = state.buf.save(Path::new(file));
}
Key::Up => {
let _ = state.up();
let _ = state.repaint_line_full();
let _ = stdout().flush();
}
Key::Down => {
let _ = state.down();
let _ = state.repaint_line_full();
let _ = stdout().flush();
}
Key::Left => {
let _ = state.left();
let _ = state.repaint_line_full();
let _ = stdout().flush();
}
Key::Right => {
let _ = state.right();
let _ = state.repaint_line_full();
let _ = stdout().flush();
}
Key::Char(b'\r') => {
state.buf = state.buf.insert(state.buf.line_idx(state.row_start+state.cursor_row)+state.line_offset, b'\n');
if state.cursor_row == usize::from(size.ws_row - 1) {
state.row_start += 1;
} else {
state.cursor_row += 1;
}
state.cursor_col = 0;
let _ = state.repaint_all();
let _ = state.repaint_line_full();
let _ = stdout().flush();
}
Key::Char(c) => {
state.cursor_col = std::cmp::min(state.cursor_col, state.line_cols);
state.buf = state.buf.insert(state.buf.line_idx(state.row_start+state.cursor_row)+state.line_offset, c);
state.cursor_col += 1;
let _ = state.repaint_line_full();
let _ = stdout().flush();
}
}
}
return Ok(());
}
fn main() {
let args: Vec<OsString> = std::env::args_os().collect();
if args.len() != 2 {
println!("Usage: edit <filename>");
std::process::exit(1);
}
if let Err(err) = edit(&args[1]) {
println!("FAIL: {}", err);
std::process::exit(1);
}
}
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