use clap::ArgMatches as Args; use helix_core::{indent::TAB_WIDTH, state::Mode, syntax::HighlightEvent, Position, Range, State}; use helix_view::{commands, keymap, prompt::Prompt, Editor, View}; use std::{ borrow::Cow, io::{self, stdout, Stdout, Write}, path::PathBuf, time::Duration, }; use smol::prelude::*; use anyhow::Error; use crossterm::{ cursor, cursor::position, event::{self, read, Event, EventStream, KeyCode, KeyEvent}, execute, queue, terminal::{self, disable_raw_mode, enable_raw_mode}, }; use tui::{ backend::CrosstermBackend, buffer::Buffer as Surface, layout::Rect, style::{Color, Style}, }; const OFFSET: u16 = 6; // 5 linenr + 1 gutter type Terminal = tui::Terminal>; static EX: smol::Executor = smol::Executor::new(); pub struct Application { editor: Editor, prompt: Option, terminal: Renderer, } struct Renderer { size: (u16, u16), terminal: Terminal, surface: Surface, cache: Surface, text_color: Style, } impl Renderer { pub fn new() -> Result { let backend = CrosstermBackend::new(stdout()); let mut terminal = Terminal::new(backend)?; let size = terminal::size().unwrap(); let text_color: Style = Style::default().fg(Color::Rgb(219, 191, 239)); // lilac let area = Rect::new(0, 0, size.0, size.1); Ok(Self { size, terminal, surface: Surface::empty(area), cache: Surface::empty(area), text_color, }) } pub fn resize(&mut self, width: u16, height: u16) { self.size = (width, height); let area = Rect::new(0, 0, width, height); self.surface = Surface::empty(area); self.cache = Surface::empty(area); } pub fn render_view(&mut self, view: &mut View, viewport: Rect) { self.render_buffer(view, viewport); self.render_statusline(view); } // TODO: ideally not &mut View but highlights require it because of cursor cache pub fn render_buffer(&mut self, view: &mut View, viewport: Rect) { let area = Rect::new(0, 0, self.size.0, self.size.1); self.surface.reset(); // reset is faster than allocating new empty surface // clear with background color self.surface .set_style(area, view.theme.get("ui.background")); // TODO: inefficient, should feed chunks.iter() to tree_sitter.parse_with(|offset, pos|) let source_code = view.state.doc().to_string(); let last_line = view.last_line(); let range = { // calculate viewport byte ranges let start = view.state.doc().line_to_byte(view.first_line); let end = view.state.doc().line_to_byte(last_line) + view.state.doc().line(last_line).len_bytes(); start..end }; // TODO: range doesn't actually restrict source, just highlight range // TODO: cache highlight results // TODO: only recalculate when state.doc is actually modified let highlights: Vec<_> = match view.state.syntax.as_mut() { Some(syntax) => { syntax .highlight_iter(source_code.as_bytes(), Some(range), None, |_| None) .unwrap() .collect() // TODO: we collect here to avoid double borrow, fix later } None => vec![Ok(HighlightEvent::Source { start: range.start, end: range.end, })], }; let mut spans = Vec::new(); let mut visual_x = 0; let mut line = 0u16; let visible_selections: Vec = view .state .selection() .ranges() .iter() // TODO: limit selection to one in viewport // .filter(|range| !range.is_empty()) // && range.overlaps(&Range::new(start, end + 1)) .copied() .collect(); 'outer: for event in highlights { match event.unwrap() { HighlightEvent::HighlightStart(span) => { spans.push(span); } HighlightEvent::HighlightEnd => { spans.pop(); } HighlightEvent::Source { start, end } => { // TODO: filter out spans out of viewport for now.. let start = view.state.doc().byte_to_char(start); let end = view.state.doc().byte_to_char(end); // <-- index 744, len 743 let text = view.state.doc().slice(start..end); use helix_core::graphemes::{grapheme_width, RopeGraphemes}; let style = match spans.first() { Some(span) => view.theme.get(view.theme.scopes()[span.0].as_str()), None => Style::default().fg(Color::Rgb(164, 160, 232)), // lavender }; // TODO: we could render the text to a surface, then cache that, that // way if only the selection/cursor changes we can copy from cache // and paint the new cursor. let mut char_index = start; // iterate over range char by char for grapheme in RopeGraphemes::new(&text) { // TODO: track current char_index if grapheme == "\n" { visual_x = 0; line += 1; // TODO: with proper iter this shouldn't be necessary if line >= viewport.height { break 'outer; } } else if grapheme == "\t" { visual_x += (TAB_WIDTH as u16); } else { // Cow will prevent allocations if span contained in a single slice // which should really be the majority case let grapheme = Cow::from(grapheme); let width = grapheme_width(&grapheme) as u16; // TODO: this should really happen as an after pass let style = if visible_selections .iter() .any(|range| range.contains(char_index)) { // cedar style.clone().bg(Color::Rgb(128, 47, 0)) } else { style }; let style = if visible_selections .iter() .any(|range| range.head == char_index) { style.clone().bg(Color::Rgb(255, 255, 255)) } else { style }; // TODO: paint cursor heads except primary self.surface .set_string(OFFSET + visual_x, line, grapheme, style); visual_x += width; } // if grapheme == "\t" char_index += 1; } } } } let style: Style = view.theme.get("ui.linenr"); let last_line = view.last_line(); for (i, line) in (view.first_line..last_line).enumerate() { self.surface .set_stringn(0, i as u16, format!("{:>5}", line + 1), 5, style); } } pub fn render_statusline(&mut self, view: &View) { let mode = match view.state.mode() { Mode::Insert => "INS", Mode::Normal => "NOR", Mode::Goto => "GOTO", Mode::Command => "COM", // command? }; // statusline self.surface.set_style( Rect::new(0, self.size.1 - 2, self.size.0, 1), view.theme.get("ui.statusline"), ); self.surface .set_string(1, self.size.1 - 2, mode, self.text_color); } pub fn render_prompt(&mut self, prompt: &Prompt) { use tui::backend::Backend; // render buffer text self.surface .set_string(1, self.size.1 - 1, String::from(":"), self.text_color); self.surface .set_string(2, self.size.1 - 1, &prompt.buffer, self.text_color); // TODO: theres probably a better place for this self.terminal .backend_mut() .draw(self.cache.diff(&self.surface).into_iter()); // swap the buffer std::mem::swap(&mut self.surface, &mut self.cache); } pub fn render_cursor(&mut self, view: &View, prompt: Option<&Prompt>, viewport: Rect) { let mut stdout = stdout(); match view.state.mode() { Mode::Insert => write!(stdout, "\x1B[6 q"), mode => write!(stdout, "\x1B[2 q"), }; let pos = if let Some(prompt) = prompt { Position::new(self.size.0 as usize, 2 + prompt.cursor_loc) } else { if let Some(path) = view.state.path() { self.surface.set_string( 6, self.size.1 - 1, path.to_string_lossy(), self.text_color, ); } let cursor = view.state.selection().cursor(); let mut pos = view .screen_coords_at_pos(&view.state.doc().slice(..), cursor) .expect("Cursor is out of bounds."); pos.col += viewport.x as usize; pos.row += viewport.y as usize; pos }; execute!(stdout, cursor::MoveTo(pos.col as u16, pos.row as u16)); } } impl Application { pub fn new(mut args: Args) -> Result { let terminal = Renderer::new()?; let mut editor = Editor::new(); if let Some(file) = args.values_of_t::("files").unwrap().pop() { editor.open(file, terminal.size)?; } let mut app = Self { editor, terminal, // TODO; move to state prompt: None, }; Ok(app) } pub fn set_prompt(&mut self) { let commands = |editor: &mut Editor, input: &str| match input { "q" => editor.should_close = true, _ => (), }; let prompt = Prompt::new(|input| None, commands); self.prompt = Some(prompt); } fn render(&mut self) { let viewport = Rect::new(OFFSET, 0, self.terminal.size.0, self.terminal.size.1 - 2); // - 2 for statusline and prompt if let Some(view) = &mut self.editor.view { self.terminal.render_view(view, viewport); } if let Some(prompt) = &self.prompt { self.terminal.render_prompt(prompt); } // TODO: drop unwrap self.terminal.render_cursor( self.editor.view.as_ref().unwrap(), self.prompt.as_ref(), viewport, ); } pub async fn event_loop(&mut self) { let mut reader = EventStream::new(); let keymap = keymap::default(); self.set_prompt(); self.render(); loop { if self.editor.should_close { break; } // Handle key events match reader.next().await { Some(Ok(Event::Resize(width, height))) => { self.terminal.resize(width, height); // TODO: simplistic ensure cursor in view for now if let Some(view) = &mut self.editor.view { view.size = self.terminal.size; view.ensure_cursor_in_view() }; self.render(); } Some(Ok(Event::Key(event))) => { // if there's a prompt, it takes priority if let Some(prompt) = &mut self.prompt { self.prompt .as_mut() .unwrap() .handle_input(event, &mut self.editor); } else if let Some(view) = &mut self.editor.view { let keys = vec![event]; // TODO: sequences (`gg`) // TODO: handle count other than 1 match view.state.mode() { Mode::Insert => { if let Some(command) = keymap[&Mode::Insert].get(&keys) { command(view, 1); } else if let KeyEvent { code: KeyCode::Char(c), .. } = event { commands::insert::insert_char(view, c); } view.ensure_cursor_in_view(); } Mode::Command => unreachable!(), mode => { if let Some(command) = keymap[&mode].get(&keys) { command(view, 1); // TODO: simplistic ensure cursor in view for now view.ensure_cursor_in_view(); } } } self.render(); } } Some(Ok(Event::Mouse(_))) => (), // unhandled Some(Err(x)) => panic!(x), None => break, } } } pub async fn run(&mut self) -> Result<(), Error> { enable_raw_mode()?; let mut stdout = stdout(); execute!(stdout, terminal::EnterAlternateScreen)?; // Exit the alternate screen and disable raw mode before panicking let hook = std::panic::take_hook(); std::panic::set_hook(Box::new(move |info| { execute!(std::io::stdout(), terminal::LeaveAlternateScreen); disable_raw_mode(); hook(info); })); self.event_loop().await; // reset cursor shape write!(stdout, "\x1B[2 q"); execute!(stdout, terminal::LeaveAlternateScreen)?; disable_raw_mode()?; Ok(()) } } // TODO: language configs: // tabSize, fileExtension etc, mapping to tree sitter parser // themes: // map tree sitter highlights to color values // // TODO: expand highlight thing so we're able to render only viewport range // TODO: async: maybe pre-cache scopes as empty so we render all graphemes initially as regular ////text until calc finishes // TODO: scope matching: biggest union match? [string] & [html, string], [string, html] & [ string, html] // can do this by sorting our theme matches based on array len (longest first) then stopping at the // first rule that matches (rule.all(|scope| scopes.contains(scope)))