use crate::Document;
use crate::Row;
use crate::Terminal;
use std::env;
use std::time::Duration;
use std::time::Instant;
use termion::color;
use termion::event::Key;
const STATUS_FG_COLOR: color::Rgb = color::Rgb(63, 63, 63);
const STATUS_BG_COLOR: color::Rgb = color::Rgb(239, 239, 239);
const VERSION: &str = env!("CARGO_PKG_VERSION");
const QUIT_TIMES: u8 = 3;
#[derive(PartialEq, Copy, Clone)]
pub enum SearchDirection {
Forward,
Backward,
}
#[derive(Default, Clone)]
pub struct Position {
pub x: usize,
pub y: usize,
}
struct StatusMessage {
text: String,
time: Instant,
}
impl StatusMessage {
fn from(message: String) -> Self {
Self {
time: Instant::now(),
text: message,
}
}
}
pub struct Editor {
should_quit: bool,
terminal: Terminal,
cursor_position: Position,
offset: Position,
document: Document,
status_message: StatusMessage,
quit_times: u8,
highlighted_word: Option<String>,
}
impl Editor {
pub fn run(&mut self) {
loop {
if let Err(error) = self.refresh_screen() {
die(error);
}
if self.should_quit {
break;
}
if let Err(error) = self.process_keypress() {
die(error);
}
}
}
pub fn default() -> Self {
let args: Vec<String> = env::args().collect();
let mut initial_status =
String::from("HELP: Ctrl-F = find | Ctrl-S = save | Ctrl-Q = quit");
let document = if let Some(file_name) = args.get(1) {
let doc = Document::open(file_name);
if let Ok(doc) = doc {
doc
} else {
initial_status = format!("ERR: Could not open file: {}", file_name);
Document::default()
}
} else {
Document::default()
};
Self {
should_quit: false,
terminal: Terminal::default().expect("Failed to initialize terminal"),
document,
cursor_position: Position::default(),
offset: Position::default(),
status_message: StatusMessage::from(initial_status),
quit_times: QUIT_TIMES,
highlighted_word: None,
}
}
fn refresh_screen(&mut self) -> Result<(), std::io::Error> {
Terminal::cursor_hide();
Terminal::cursor_position(&Position::default());
if self.should_quit {
Terminal::clear_screen();
println!("Goodbye.\r");
} else {
self.document.highlight(
&self.highlighted_word,
Some(
self.offset
.y
.saturating_add(self.terminal.size().height as usize),
),
);
self.draw_rows();
self.draw_status_bar();
self.draw_message_bar();
Terminal::cursor_position(&Position {
x: self.cursor_position.x.saturating_sub(self.offset.x),
y: self.cursor_position.y.saturating_sub(self.offset.y),
});
}
Terminal::cursor_show();
Terminal::flush()
}
fn save(&mut self) {
if self.document.file_name.is_none() {
let new_name = self.prompt("Save as: ", |_, _, _| {}).unwrap_or(None);
if new_name.is_none() {
self.status_message = StatusMessage::from("Save aborted.".to_string());
return;
}
self.document.file_name = new_name;
}
if self.document.save().is_ok() {
self.status_message = StatusMessage::from("File saved successfully.".to_string());
} else {
self.status_message = StatusMessage::from("Error writing file!".to_string());
}
}
fn search(&mut self) {
let old_position = self.cursor_position.clone();
let mut direction = SearchDirection::Forward;
let query = self
.prompt(
"Search (ESC to cancel, Arrows to navigate): ",
|editor, key, query| {
let mut moved = false;
match key {
Key::Right | Key::Down => {
direction = SearchDirection::Forward;
editor.move_cursor(Key::Right);
moved = true;
}
Key::Left | Key::Up => direction = SearchDirection::Backward,
_ => direction = SearchDirection::Forward,
}
if let Some(position) =
editor
.document
.find(&query, &editor.cursor_position, direction)
{
editor.cursor_position = position;
editor.scroll();
} else if moved {
editor.move_cursor(Key::Left);
}
editor.highlighted_word = Some(query.to_string());
},
)
.unwrap_or(None);
if query.is_none() {
self.cursor_position = old_position;
self.scroll();
}
self.highlighted_word = None;
}
fn process_keypress(&mut self) -> Result<(), std::io::Error> {
let pressed_key = Terminal::read_key()?;
match pressed_key {
Key::Ctrl('q') => {
if self.quit_times > 0 && self.document.is_dirty() {
self.status_message = StatusMessage::from(format!(
"WARNING! File has unsaved changes. Press Ctrl-Q {} more times to quit.",
self.quit_times
));
self.quit_times -= 1;
return Ok(());
}
self.should_quit = true
}
Key::Ctrl('s') => self.save(),
Key::Ctrl('f') => self.search(),
Key::Char(c) => {
self.document.insert(&self.cursor_position, c);
self.move_cursor(Key::Right);
}
Key::Delete => self.document.delete(&self.cursor_position),
Key::Backspace => {
if self.cursor_position.x > 0 || self.cursor_position.y > 0 {
self.move_cursor(Key::Left);
self.document.delete(&self.cursor_position);
}
}
Key::Up
| Key::Down
| Key::Left
| Key::Right
| Key::PageUp
| Key::PageDown
| Key::End
| Key::Home => self.move_cursor(pressed_key),
_ => (),
}
self.scroll();
if self.quit_times < QUIT_TIMES {
self.quit_times = QUIT_TIMES;
self.status_message = StatusMessage::from(String::new());
}
Ok(())
}
fn scroll(&mut self) {
let Position { x, y } = self.cursor_position;
let width = self.terminal.size().width as usize;
let height = self.terminal.size().height as usize;
let mut offset = &mut self.offset;
if y < offset.y {
offset.y = y;
} else if y >= offset.y.saturating_add(height) {
offset.y = y.saturating_sub(height).saturating_add(1);
}
if x < offset.x {
offset.x = x;
} else if x >= offset.x.saturating_add(width) {
offset.x = x.saturating_sub(width).saturating_add(1);
}
}
fn move_cursor(&mut self, key: Key) {
let terminal_height = self.terminal.size().height as usize;
let Position { mut y, mut x } = self.cursor_position;
let height = self.document.len();
let mut width = if let Some(row) = self.document.row(y) {
row.len()
} else {
0
};
match key {
Key::Up => y = y.saturating_sub(1),
Key::Down => {
if y < height {
y = y.saturating_add(1);
}
}
Key::Left => {
if x > 0 {
x -= 1;
} else if y > 0 {
y -= 1;
if let Some(row) = self.document.row(y) {
x = row.len();
} else {
x = 0;
}
}
}
Key::Right => {
if x < width {
x += 1;
} else if y < height {
y += 1;
x = 0;
}
}
Key::PageUp => {
y = if y > terminal_height {
y.saturating_sub(terminal_height)
} else {
0
}
}
Key::PageDown => {
y = if y.saturating_add(terminal_height) < height {
y.saturating_add(terminal_height)
} else {
height
}
}
Key::Home => x = 0,
Key::End => x = width,
_ => (),
}
width = if let Some(row) = self.document.row(y) {
row.len()
} else {
0
};
if x > width {
x = width;
}
self.cursor_position = Position { x, y }
}
fn draw_welcome_message(&self) {
let mut welcome_message = format!("Hecto editor -- version {}", VERSION);
let width = self.terminal.size().width as usize;
let len = welcome_message.len();
#[allow(clippy::integer_arithmetic, clippy::integer_division)]
let padding = width.saturating_sub(len) / 2;
let spaces = " ".repeat(padding.saturating_sub(1));
welcome_message = format!("~{}{}", spaces, welcome_message);
welcome_message.truncate(width);
println!("{}\r", welcome_message);
}
pub fn draw_row(&self, row: &Row) {
let width = self.terminal.size().width as usize;
let start = self.offset.x;
let end = self.offset.x.saturating_add(width);
let row = row.render(start, end);
println!("{}\r", row)
}
#[allow(clippy::integer_division, clippy::integer_arithmetic)]
fn draw_rows(&self) {
let height = self.terminal.size().height;
for terminal_row in 0..height {
Terminal::clear_current_line();
if let Some(row) = self
.document
.row(self.offset.y.saturating_add(terminal_row as usize))
{
self.draw_row(row);
} else if self.document.is_empty() && terminal_row == height / 3 {
self.draw_welcome_message();
} else {
println!("~\r");
}
}
}
fn draw_status_bar(&self) {
let mut status;
let width = self.terminal.size().width as usize;
let modified_indicator = if self.document.is_dirty() {
" (modified)"
} else {
""
};
let mut file_name = "[No Name]".to_string();
if let Some(name) = &self.document.file_name {
file_name = name.clone();
file_name.truncate(20);
}
status = format!(
"{} - {} lines{}",
file_name,
self.document.len(),
modified_indicator
);
let line_indicator = format!(
"{} | {}/{}",
self.document.file_type(),
self.cursor_position.y.saturating_add(1),
self.document.len()
);
#[allow(clippy::integer_arithmetic)]
let len = status.len() + line_indicator.len();
status.push_str(&" ".repeat(width.saturating_sub(len)));
status = format!("{}{}", status, line_indicator);
status.truncate(width);
Terminal::set_bg_color(STATUS_BG_COLOR);
Terminal::set_fg_color(STATUS_FG_COLOR);
println!("{}\r", status);
Terminal::reset_fg_color();
Terminal::reset_bg_color();
}
fn draw_message_bar(&self) {
Terminal::clear_current_line();
let message = &self.status_message;
if Instant::now() - message.time < Duration::new(5, 0) {
let mut text = message.text.clone();
text.truncate(self.terminal.size().width as usize);
print!("{}", text);
}
}
fn prompt<C>(&mut self, prompt: &str, mut callback: C) -> Result<Option<String>, std::io::Error>
where
C: FnMut(&mut Self, Key, &String),
{
let mut result = String::new();
loop {
self.status_message = StatusMessage::from(format!("{}{}", prompt, result));
self.refresh_screen()?;
let key = Terminal::read_key()?;
match key {
Key::Backspace => result.truncate(result.len().saturating_sub(1)),
Key::Char('\n') => break,
Key::Char(c) => {
if !c.is_control() {
result.push(c);
}
}
Key::Esc => {
result.truncate(0);
break;
}
_ => (),
}
callback(self, key, &result);
}
self.status_message = StatusMessage::from(String::new());
if result.is_empty() {
return Ok(None);
}
Ok(Some(result))
}
}
fn die(e: std::io::Error) {
Terminal::clear_screen();
panic!(e);
}