stdio.rs

  1use crate::outputs::{ExecutionView, LineHeight};
  2use alacritty_terminal::vte::{
  3    ansi::{Attr, Color, NamedColor, Rgb},
  4    Params, ParamsIter, Parser, Perform,
  5};
  6use core::iter;
  7use gpui::{font, prelude::*, AnyElement, StyledText, TextRun};
  8use settings::Settings as _;
  9use theme::ThemeSettings;
 10use ui::{div, prelude::*, IntoElement, ViewContext, WindowContext};
 11
 12/// Implements the most basic of terminal output for use by Jupyter outputs
 13/// whether:
 14///
 15/// * stdout
 16/// * stderr
 17/// * text/plain
 18/// * traceback from an error output
 19///
 20/// Ideally, we would instead use alacritty::vte::Processor to collect the
 21/// output and then render up to u8::MAX lines of text. However, it's likely
 22/// overkill for 95% of outputs.
 23///
 24/// Instead, this implementation handles:
 25///
 26/// * ANSI color codes (background, foreground), including 256 color
 27/// * Carriage returns/line feeds
 28///
 29/// There is no support for cursor movement, clearing the screen, and other text styles
 30pub struct TerminalOutput {
 31    parser: Parser,
 32    handler: TerminalHandler,
 33}
 34
 35impl TerminalOutput {
 36    pub fn new() -> Self {
 37        Self {
 38            parser: Parser::new(),
 39            handler: TerminalHandler::new(),
 40        }
 41    }
 42
 43    pub fn from(text: &str) -> Self {
 44        let mut output = Self::new();
 45        output.append_text(text);
 46        output
 47    }
 48
 49    pub fn append_text(&mut self, text: &str) {
 50        for byte in text.as_bytes() {
 51            self.parser.advance(&mut self.handler, *byte);
 52        }
 53    }
 54
 55    pub fn render(&self, cx: &ViewContext<ExecutionView>) -> AnyElement {
 56        let theme = cx.theme();
 57        let buffer_font = ThemeSettings::get_global(cx).buffer_font.family.clone();
 58        let runs = self
 59            .handler
 60            .text_runs
 61            .iter()
 62            .chain(Some(&self.handler.current_text_run))
 63            .map(|ansi_run| {
 64                let color = terminal_view::terminal_element::convert_color(&ansi_run.fg, theme);
 65                let background_color = Some(terminal_view::terminal_element::convert_color(
 66                    &ansi_run.bg,
 67                    theme,
 68                ));
 69
 70                TextRun {
 71                    len: ansi_run.len,
 72                    color,
 73                    background_color,
 74                    underline: Default::default(),
 75                    font: font(buffer_font.clone()),
 76                    strikethrough: None,
 77                }
 78            })
 79            .collect::<Vec<TextRun>>();
 80
 81        // Trim the last trailing newline for visual appeal
 82        let trimmed = self
 83            .handler
 84            .buffer
 85            .strip_suffix('\n')
 86            .unwrap_or(&self.handler.buffer);
 87
 88        let text = StyledText::new(trimmed.to_string()).with_runs(runs);
 89        div()
 90            .font_family(buffer_font)
 91            .child(text)
 92            .into_any_element()
 93    }
 94}
 95
 96impl LineHeight for TerminalOutput {
 97    fn num_lines(&self, _cx: &mut WindowContext) -> u8 {
 98        self.handler.buffer.lines().count().max(1) as u8
 99    }
100}
101
102#[derive(Clone)]
103struct AnsiTextRun {
104    len: usize,
105    fg: alacritty_terminal::vte::ansi::Color,
106    bg: alacritty_terminal::vte::ansi::Color,
107}
108
109impl AnsiTextRun {
110    fn default() -> Self {
111        Self {
112            len: 0,
113            fg: Color::Named(NamedColor::Foreground),
114            bg: Color::Named(NamedColor::Background),
115        }
116    }
117}
118
119struct TerminalHandler {
120    text_runs: Vec<AnsiTextRun>,
121    current_text_run: AnsiTextRun,
122    buffer: String,
123}
124
125impl TerminalHandler {
126    fn new() -> Self {
127        Self {
128            text_runs: Vec::new(),
129            current_text_run: AnsiTextRun {
130                len: 0,
131                fg: Color::Named(NamedColor::Foreground),
132                bg: Color::Named(NamedColor::Background),
133            },
134            buffer: String::new(),
135        }
136    }
137
138    fn add_text(&mut self, c: char) {
139        self.buffer.push(c);
140        self.current_text_run.len += 1;
141    }
142
143    fn reset(&mut self) {
144        if self.current_text_run.len > 0 {
145            self.text_runs.push(self.current_text_run.clone());
146        }
147
148        self.current_text_run = AnsiTextRun::default();
149    }
150
151    fn terminal_attribute(&mut self, attr: Attr) {
152        // println!("[terminal_attribute] attr={:?}", attr);
153        if Attr::Reset == attr {
154            self.reset();
155            return;
156        }
157
158        if self.current_text_run.len > 0 {
159            self.text_runs.push(self.current_text_run.clone());
160        }
161
162        let mut text_run = AnsiTextRun {
163            len: 0,
164            fg: self.current_text_run.fg,
165            bg: self.current_text_run.bg,
166        };
167
168        match attr {
169            Attr::Foreground(color) => text_run.fg = color,
170            Attr::Background(color) => text_run.bg = color,
171            _ => {}
172        }
173
174        self.current_text_run = text_run;
175    }
176
177    fn process_carriage_return(&mut self) {
178        // Find last carriage return's position
179        let last_cr = self.buffer.rfind('\r').unwrap_or(0);
180        self.buffer = self.buffer.chars().take(last_cr).collect();
181
182        // First work through our current text run
183        let mut total_len = self.current_text_run.len;
184        if total_len > last_cr {
185            // We are in the current text run
186            self.current_text_run.len = self.current_text_run.len - last_cr;
187        } else {
188            let mut last_cr_run = 0;
189            // Find the last run before the last carriage return
190            for (i, run) in self.text_runs.iter().enumerate() {
191                total_len += run.len;
192                if total_len > last_cr {
193                    last_cr_run = i;
194                    break;
195                }
196            }
197            self.text_runs = self.text_runs[..last_cr_run].to_vec();
198            self.current_text_run = self.text_runs.pop().unwrap_or(AnsiTextRun::default());
199        }
200
201        self.buffer.push('\r');
202        self.current_text_run.len += 1;
203    }
204}
205
206impl Perform for TerminalHandler {
207    fn print(&mut self, c: char) {
208        // println!("[print] c={:?}", c);
209        self.add_text(c);
210    }
211
212    fn execute(&mut self, byte: u8) {
213        match byte {
214            b'\n' => {
215                self.add_text('\n');
216            }
217            b'\r' => {
218                self.process_carriage_return();
219            }
220            _ => {
221                // Format as hex
222                // println!("[execute] byte={:02x}", byte);
223            }
224        }
225    }
226
227    fn hook(&mut self, _params: &Params, _intermediates: &[u8], _ignore: bool, _c: char) {
228        // noop
229        // println!(
230        //     "[hook] params={:?}, intermediates={:?}, c={:?}",
231        //     _params, _intermediates, _c
232        // );
233    }
234
235    fn put(&mut self, _byte: u8) {
236        // noop
237        // println!("[put] byte={:02x}", _byte);
238    }
239
240    fn unhook(&mut self) {
241        // noop
242    }
243
244    fn osc_dispatch(&mut self, _params: &[&[u8]], _bell_terminated: bool) {
245        // noop
246        // println!("[osc_dispatch] params={:?}", _params);
247    }
248
249    fn csi_dispatch(
250        &mut self,
251        params: &alacritty_terminal::vte::Params,
252        intermediates: &[u8],
253        _ignore: bool,
254        action: char,
255    ) {
256        // println!(
257        //     "[csi_dispatch] action={:?}, params={:?}, intermediates={:?}",
258        //     action, params, intermediates
259        // );
260
261        let mut params_iter = params.iter();
262        // Collect colors
263        match (action, intermediates) {
264            ('m', []) => {
265                if params.is_empty() {
266                    self.terminal_attribute(Attr::Reset);
267                } else {
268                    for attr in attrs_from_sgr_parameters(&mut params_iter) {
269                        match attr {
270                            Some(attr) => self.terminal_attribute(attr),
271                            None => return,
272                        }
273                    }
274                }
275            }
276            _ => {}
277        }
278    }
279
280    fn esc_dispatch(&mut self, _intermediates: &[u8], _ignore: bool, _byte: u8) {
281        // noop
282        // println!(
283        //     "[esc_dispatch] intermediates={:?}, byte={:?}",
284        //     _intermediates, _byte
285        // );
286    }
287}
288
289// The following was pulled from vte::ansi
290#[inline]
291fn attrs_from_sgr_parameters(params: &mut ParamsIter<'_>) -> Vec<Option<Attr>> {
292    let mut attrs = Vec::with_capacity(params.size_hint().0);
293
294    while let Some(param) = params.next() {
295        let attr = match param {
296            [0] => Some(Attr::Reset),
297            [1] => Some(Attr::Bold),
298            [2] => Some(Attr::Dim),
299            [3] => Some(Attr::Italic),
300            [4, 0] => Some(Attr::CancelUnderline),
301            [4, 2] => Some(Attr::DoubleUnderline),
302            [4, 3] => Some(Attr::Undercurl),
303            [4, 4] => Some(Attr::DottedUnderline),
304            [4, 5] => Some(Attr::DashedUnderline),
305            [4, ..] => Some(Attr::Underline),
306            [5] => Some(Attr::BlinkSlow),
307            [6] => Some(Attr::BlinkFast),
308            [7] => Some(Attr::Reverse),
309            [8] => Some(Attr::Hidden),
310            [9] => Some(Attr::Strike),
311            [21] => Some(Attr::CancelBold),
312            [22] => Some(Attr::CancelBoldDim),
313            [23] => Some(Attr::CancelItalic),
314            [24] => Some(Attr::CancelUnderline),
315            [25] => Some(Attr::CancelBlink),
316            [27] => Some(Attr::CancelReverse),
317            [28] => Some(Attr::CancelHidden),
318            [29] => Some(Attr::CancelStrike),
319            [30] => Some(Attr::Foreground(Color::Named(NamedColor::Black))),
320            [31] => Some(Attr::Foreground(Color::Named(NamedColor::Red))),
321            [32] => Some(Attr::Foreground(Color::Named(NamedColor::Green))),
322            [33] => Some(Attr::Foreground(Color::Named(NamedColor::Yellow))),
323            [34] => Some(Attr::Foreground(Color::Named(NamedColor::Blue))),
324            [35] => Some(Attr::Foreground(Color::Named(NamedColor::Magenta))),
325            [36] => Some(Attr::Foreground(Color::Named(NamedColor::Cyan))),
326            [37] => Some(Attr::Foreground(Color::Named(NamedColor::White))),
327            [38] => {
328                let mut iter = params.map(|param| param[0]);
329                parse_sgr_color(&mut iter).map(Attr::Foreground)
330            }
331            [38, params @ ..] => handle_colon_rgb(params).map(Attr::Foreground),
332            [39] => Some(Attr::Foreground(Color::Named(NamedColor::Foreground))),
333            [40] => Some(Attr::Background(Color::Named(NamedColor::Black))),
334            [41] => Some(Attr::Background(Color::Named(NamedColor::Red))),
335            [42] => Some(Attr::Background(Color::Named(NamedColor::Green))),
336            [43] => Some(Attr::Background(Color::Named(NamedColor::Yellow))),
337            [44] => Some(Attr::Background(Color::Named(NamedColor::Blue))),
338            [45] => Some(Attr::Background(Color::Named(NamedColor::Magenta))),
339            [46] => Some(Attr::Background(Color::Named(NamedColor::Cyan))),
340            [47] => Some(Attr::Background(Color::Named(NamedColor::White))),
341            [48] => {
342                let mut iter = params.map(|param| param[0]);
343                parse_sgr_color(&mut iter).map(Attr::Background)
344            }
345            [48, params @ ..] => handle_colon_rgb(params).map(Attr::Background),
346            [49] => Some(Attr::Background(Color::Named(NamedColor::Background))),
347            [58] => {
348                let mut iter = params.map(|param| param[0]);
349                parse_sgr_color(&mut iter).map(|color| Attr::UnderlineColor(Some(color)))
350            }
351            [58, params @ ..] => {
352                handle_colon_rgb(params).map(|color| Attr::UnderlineColor(Some(color)))
353            }
354            [59] => Some(Attr::UnderlineColor(None)),
355            [90] => Some(Attr::Foreground(Color::Named(NamedColor::BrightBlack))),
356            [91] => Some(Attr::Foreground(Color::Named(NamedColor::BrightRed))),
357            [92] => Some(Attr::Foreground(Color::Named(NamedColor::BrightGreen))),
358            [93] => Some(Attr::Foreground(Color::Named(NamedColor::BrightYellow))),
359            [94] => Some(Attr::Foreground(Color::Named(NamedColor::BrightBlue))),
360            [95] => Some(Attr::Foreground(Color::Named(NamedColor::BrightMagenta))),
361            [96] => Some(Attr::Foreground(Color::Named(NamedColor::BrightCyan))),
362            [97] => Some(Attr::Foreground(Color::Named(NamedColor::BrightWhite))),
363            [100] => Some(Attr::Background(Color::Named(NamedColor::BrightBlack))),
364            [101] => Some(Attr::Background(Color::Named(NamedColor::BrightRed))),
365            [102] => Some(Attr::Background(Color::Named(NamedColor::BrightGreen))),
366            [103] => Some(Attr::Background(Color::Named(NamedColor::BrightYellow))),
367            [104] => Some(Attr::Background(Color::Named(NamedColor::BrightBlue))),
368            [105] => Some(Attr::Background(Color::Named(NamedColor::BrightMagenta))),
369            [106] => Some(Attr::Background(Color::Named(NamedColor::BrightCyan))),
370            [107] => Some(Attr::Background(Color::Named(NamedColor::BrightWhite))),
371            _ => None,
372        };
373        attrs.push(attr);
374    }
375
376    attrs
377}
378
379/// Handle colon separated rgb color escape sequence.
380#[inline]
381fn handle_colon_rgb(params: &[u16]) -> Option<Color> {
382    let rgb_start = if params.len() > 4 { 2 } else { 1 };
383    let rgb_iter = params[rgb_start..].iter().copied();
384    let mut iter = iter::once(params[0]).chain(rgb_iter);
385
386    parse_sgr_color(&mut iter)
387}
388
389/// Parse a color specifier from list of attributes.
390fn parse_sgr_color(params: &mut dyn Iterator<Item = u16>) -> Option<Color> {
391    match params.next() {
392        Some(2) => Some(Color::Spec(Rgb {
393            r: u8::try_from(params.next()?).ok()?,
394            g: u8::try_from(params.next()?).ok()?,
395            b: u8::try_from(params.next()?).ok()?,
396        })),
397        Some(5) => Some(Color::Indexed(u8::try_from(params.next()?).ok()?)),
398        _ => None,
399    }
400}