1//! # Plain Text Output
2//!
3//! This module provides functionality for rendering plain text output in a terminal-like format.
4//! It uses the Alacritty terminal emulator backend to process and display text, supporting
5//! ANSI escape sequences for formatting, colors, and other terminal features.
6//!
7//! The main component of this module is the `TerminalOutput` struct, which handles the parsing
8//! and rendering of text input, simulating a basic terminal environment within REPL output.
9//!
10//! This module is used for displaying:
11//!
12//! - Standard output (stdout)
13//! - Standard error (stderr)
14//! - Plain text content
15//! - Error tracebacks
16//!
17
18use alacritty_terminal::{
19 event::VoidListener,
20 grid::Dimensions as _,
21 index::{Column, Line, Point},
22 term::Config,
23 vte::ansi::Processor,
24};
25use gpui::{canvas, size, ClipboardItem, Entity, FontStyle, TextStyle, WhiteSpace};
26use language::Buffer;
27use settings::Settings as _;
28use terminal_view::terminal_element::TerminalElement;
29use theme::ThemeSettings;
30use ui::{prelude::*, IntoElement};
31
32use crate::outputs::OutputContent;
33
34/// The `TerminalOutput` struct handles the parsing and rendering of text input,
35/// simulating a basic terminal environment within REPL output.
36///
37/// `TerminalOutput` is designed to handle various types of text-based output, including:
38///
39/// * stdout (standard output)
40/// * stderr (standard error)
41/// * text/plain content
42/// * error tracebacks
43///
44/// It uses the Alacritty terminal emulator backend to process and render text,
45/// supporting ANSI escape sequences for text formatting and colors.
46///
47pub struct TerminalOutput {
48 full_buffer: Option<Entity<Buffer>>,
49 /// ANSI escape sequence processor for parsing input text.
50 parser: Processor,
51 /// Alacritty terminal instance that manages the terminal state and content.
52 handler: alacritty_terminal::Term<VoidListener>,
53}
54
55const DEFAULT_NUM_LINES: usize = 32;
56const DEFAULT_NUM_COLUMNS: usize = 128;
57
58/// Returns the default text style for the terminal output.
59pub fn text_style(window: &mut Window, cx: &mut App) -> TextStyle {
60 let settings = ThemeSettings::get_global(cx).clone();
61
62 let font_size = settings.buffer_font_size().into();
63 let font_family = settings.buffer_font.family;
64 let font_features = settings.buffer_font.features;
65 let font_weight = settings.buffer_font.weight;
66 let font_fallbacks = settings.buffer_font.fallbacks;
67
68 let theme = cx.theme();
69
70 let text_style = TextStyle {
71 font_family,
72 font_features,
73 font_weight,
74 font_fallbacks,
75 font_size,
76 font_style: FontStyle::Normal,
77 line_height: window.line_height().into(),
78 background_color: Some(theme.colors().terminal_ansi_background),
79 white_space: WhiteSpace::Normal,
80 // These are going to be overridden per-cell
81 color: theme.colors().terminal_foreground,
82 ..Default::default()
83 };
84
85 text_style
86}
87
88/// Returns the default terminal size for the terminal output.
89pub fn terminal_size(window: &mut Window, cx: &mut App) -> terminal::TerminalSize {
90 let text_style = text_style(window, cx);
91 let text_system = window.text_system();
92
93 let line_height = window.line_height();
94
95 let font_pixels = text_style.font_size.to_pixels(window.rem_size());
96 let font_id = text_system.resolve_font(&text_style.font());
97
98 let cell_width = text_system
99 .advance(font_id, font_pixels, 'w')
100 .unwrap()
101 .width;
102
103 let num_lines = DEFAULT_NUM_LINES;
104 let columns = DEFAULT_NUM_COLUMNS;
105
106 // Reversed math from terminal::TerminalSize to get pixel width according to terminal width
107 let width = columns as f32 * cell_width;
108 let height = num_lines as f32 * window.line_height();
109
110 terminal::TerminalSize {
111 cell_width,
112 line_height,
113 size: size(width, height),
114 }
115}
116
117impl TerminalOutput {
118 /// Creates a new `TerminalOutput` instance.
119 ///
120 /// This method initializes a new terminal emulator with default configuration
121 /// and sets up the necessary components for handling terminal events and rendering.
122 ///
123 pub fn new(window: &mut Window, cx: &mut App) -> Self {
124 let term = alacritty_terminal::Term::new(
125 Config::default(),
126 &terminal_size(window, cx),
127 VoidListener,
128 );
129
130 Self {
131 parser: Processor::new(),
132 handler: term,
133 full_buffer: None,
134 }
135 }
136
137 /// Creates a new `TerminalOutput` instance with initial content.
138 ///
139 /// Initializes a new terminal output and populates it with the provided text.
140 ///
141 /// # Arguments
142 ///
143 /// * `text` - A string slice containing the initial text for the terminal output.
144 /// * `cx` - A mutable reference to the `WindowContext` for initialization.
145 ///
146 /// # Returns
147 ///
148 /// A new instance of `TerminalOutput` containing the provided text.
149 pub fn from(text: &str, window: &mut Window, cx: &mut App) -> Self {
150 let mut output = Self::new(window, cx);
151 output.append_text(text, cx);
152 output
153 }
154
155 /// Appends text to the terminal output.
156 ///
157 /// Processes each byte of the input text, handling newline characters specially
158 /// to ensure proper cursor movement. Uses the ANSI parser to process the input
159 /// and update the terminal state.
160 ///
161 /// As an example, if the user runs the following Python code in this REPL:
162 ///
163 /// ```python
164 /// import time
165 /// print("Hello,", end="")
166 /// time.sleep(1)
167 /// print(" world!")
168 /// ```
169 ///
170 /// Then append_text will be called twice, with the following arguments:
171 ///
172 /// ```rust
173 /// terminal_output.append_text("Hello,")
174 /// terminal_output.append_text(" world!")
175 /// ```
176 /// Resulting in a single output of "Hello, world!".
177 ///
178 /// # Arguments
179 ///
180 /// * `text` - A string slice containing the text to be appended.
181 pub fn append_text(&mut self, text: &str, cx: &mut App) {
182 for byte in text.as_bytes() {
183 if *byte == b'\n' {
184 // Dirty (?) hack to move the cursor down
185 self.parser.advance(&mut self.handler, &[b'\r']);
186 self.parser.advance(&mut self.handler, &[b'\n']);
187 } else {
188 self.parser.advance(&mut self.handler, &[*byte]);
189 }
190 }
191
192 // This will keep the buffer up to date, though with some terminal codes it won't be perfect
193 if let Some(buffer) = self.full_buffer.as_ref() {
194 buffer.update(cx, |buffer, cx| {
195 buffer.edit([(buffer.len()..buffer.len(), text)], None, cx);
196 });
197 }
198 }
199
200 fn full_text(&self) -> String {
201 let mut full_text = String::new();
202
203 // Get the total number of lines, including history
204 let total_lines = self.handler.grid().total_lines();
205 let visible_lines = self.handler.screen_lines();
206 let history_lines = total_lines - visible_lines;
207
208 // Capture history lines in correct order (oldest to newest)
209 for line in (0..history_lines).rev() {
210 let line_index = Line(-(line as i32) - 1);
211 let start = Point::new(line_index, Column(0));
212 let end = Point::new(line_index, Column(self.handler.columns() - 1));
213 let line_content = self.handler.bounds_to_string(start, end);
214
215 if !line_content.trim().is_empty() {
216 full_text.push_str(&line_content);
217 full_text.push('\n');
218 }
219 }
220
221 // Capture visible lines
222 for line in 0..visible_lines {
223 let line_index = Line(line as i32);
224 let start = Point::new(line_index, Column(0));
225 let end = Point::new(line_index, Column(self.handler.columns() - 1));
226 let line_content = self.handler.bounds_to_string(start, end);
227
228 if !line_content.trim().is_empty() {
229 full_text.push_str(&line_content);
230 full_text.push('\n');
231 }
232 }
233
234 // Trim any trailing newlines
235 full_text.trim_end().to_string()
236 }
237}
238
239impl Render for TerminalOutput {
240 /// Renders the terminal output as a GPUI element.
241 ///
242 /// Converts the current terminal state into a renderable GPUI element. It handles
243 /// the layout of the terminal grid, calculates the dimensions of the output, and
244 /// creates a canvas element that paints the terminal cells and background rectangles.
245 fn render(&mut self, window: &mut Window, cx: &mut Context<Self>) -> impl IntoElement {
246 let text_style = text_style(window, cx);
247 let text_system = window.text_system();
248
249 let grid = self
250 .handler
251 .renderable_content()
252 .display_iter
253 .map(|ic| terminal::IndexedCell {
254 point: ic.point,
255 cell: ic.cell.clone(),
256 });
257 let (cells, rects) =
258 TerminalElement::layout_grid(grid, &text_style, text_system, None, window, cx);
259
260 // lines are 0-indexed, so we must add 1 to get the number of lines
261 let text_line_height = text_style.line_height_in_pixels(window.rem_size());
262 let num_lines = cells.iter().map(|c| c.point.line).max().unwrap_or(0) + 1;
263 let height = num_lines as f32 * text_line_height;
264
265 let font_pixels = text_style.font_size.to_pixels(window.rem_size());
266 let font_id = text_system.resolve_font(&text_style.font());
267
268 let cell_width = text_system
269 .advance(font_id, font_pixels, 'w')
270 .map(|advance| advance.width)
271 .unwrap_or(Pixels(0.0));
272
273 canvas(
274 // prepaint
275 move |_bounds, _, _| {},
276 // paint
277 move |bounds, _, window, cx| {
278 for rect in rects {
279 rect.paint(
280 bounds.origin,
281 &terminal::TerminalSize {
282 cell_width,
283 line_height: text_line_height,
284 size: bounds.size,
285 },
286 window,
287 );
288 }
289
290 for cell in cells {
291 cell.paint(
292 bounds.origin,
293 &terminal::TerminalSize {
294 cell_width,
295 line_height: text_line_height,
296 size: bounds.size,
297 },
298 bounds,
299 window,
300 cx,
301 );
302 }
303 },
304 )
305 // We must set the height explicitly for the editor block to size itself correctly
306 .h(height)
307 }
308}
309
310impl OutputContent for TerminalOutput {
311 fn clipboard_content(&self, _window: &Window, _cx: &App) -> Option<ClipboardItem> {
312 Some(ClipboardItem::new_string(self.full_text()))
313 }
314
315 fn has_clipboard_content(&self, _window: &Window, _cx: &App) -> bool {
316 true
317 }
318
319 fn has_buffer_content(&self, _window: &Window, _cx: &App) -> bool {
320 true
321 }
322
323 fn buffer_content(&mut self, _: &mut Window, cx: &mut App) -> Option<Entity<Buffer>> {
324 if self.full_buffer.as_ref().is_some() {
325 return self.full_buffer.clone();
326 }
327
328 let buffer = cx.new(|cx| {
329 let mut buffer =
330 Buffer::local(self.full_text(), cx).with_language(language::PLAIN_TEXT.clone(), cx);
331 buffer.set_capability(language::Capability::ReadOnly, cx);
332 buffer
333 });
334
335 self.full_buffer = Some(buffer.clone());
336 Some(buffer)
337 }
338}