added --style-mode, now captures colors and such

Author: MatrixManAtYrService

README.md

@@ -65,6 +65,19 @@ Default size of the virtual terminal window is 120x40 (cols by rows), which can
 be changed with `--size` argument. For example: `ht --size 80x24`. The window
 size can also be dynamically changed - see [resize command](#resize) below.
 
+### Style Support
+
+ht supports capturing and returning terminal styling information (colors, bold, italic, etc.). Use the
+`--style-mode` option to enable styled output:
+
+- `--style-mode plain` (default) - Returns only plain text in snapshots
+- `--style-mode styled` - Includes styling information in snapshots
+
+Example:
+```sh
+ht --style-mode styled --subscribe snapshot
+```
+
 Run `ht -h` or `ht --help` to see all available options.
 
 ## Live terminal preview
@@ -205,6 +218,18 @@ specifying new width (`cols`) and height (`rows`).
 
 This command triggers `resize` event.
 
+#### setStyleMode
+
+`setStyleMode` command allows changing the style mode during runtime to enable or
+disable styled output in snapshots.
+
+```json
+{ "type": "setStyleMode", "mode": "styled" }
+{ "type": "setStyleMode", "mode": "plain" }
+```
+
+This command doesn't trigger any event but affects subsequent snapshots.
+
 ### WebSocket API
 
 The WebSocket API currently provides 2 endpoints:
@@ -280,6 +305,36 @@ Event data is an object with the following fields:
 - `text` - plain text snapshot as multi-line string, where each line represents a terminal row
 - `seq` - a raw sequence of characters, which when printed to a blank terminal puts it in the same state as [ht's virtual terminal](https://github.com/asciinema/avt)
 
+When color mode is set to `styled`, additional fields are included:
+
+- `charMap` - 2D array of characters, where `charMap[row][col]` gives the character at that position
+- `styleMap` - 2D array of style IDs, where `styleMap[row][col]` gives the style ID for the character at that position
+- `styles` - object mapping style IDs to style definitions with `fg`, `bg`, and `attrs` fields
+
+Example styled snapshot for `$ ls foo/b*` where `baz.sh` is styled differently than `bar.txt`:
+```json
+{
+  "type": "snapshot",
+  "data": {
+    "cols": 15, "rows": 2,
+    "text": "$ ls foo/b*\nbar.txt  baz.sh",
+    "charMap": [
+      ["$", " ", "l", "s", " ", "f", "o", "o", "/", "b", "*", " ", " ", " ", " "],
+      ["b", "a", "r", ".", "t", "x", "t", " ", " ", "b", "a", "z", ".", "s", "h"]
+    ],
+    "styleMap": [
+      [1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
+      [0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 2, 2, 2, 2, 2]
+    ],
+    "styles": {
+      "0": {},
+      "1": {"fg": {"indexed": 2}},
+      "2": {"fg": {"rgb": [0, 255, 127]}, "attrs": ["bold"]}
+    }
+  }
+}
+```
+
 ## Testing on command line
 
 ht is aimed at programmatic use given its JSON-based API, however one can play
@@ -303,7 +358,6 @@ TODO: either pull those into this repo or fork them into their own `htlib` repo.
 
 ## Possible future work
 
-* update the interface to return the view with additional color and style information (text color, background, bold/italic/etc) also in a simple JSON format (so no dealing with color-related escape sequence either), and the frontend could render this using HTML (e.g. with styled pre/span tags, similar to how asciinema-player does it) or with SVG.
 * support subscribing to view updates, to avoid needing to poll (see [issue #9](https://github.com/andyk/ht/issues/9))
 * native integration with asciinema for recording terminal sessions (see [issue #8](https://github.com/andyk/ht/issues/8))
 

src/api/http.rs

@@ -86,7 +86,7 @@ async fn alis_message(
     use session::Event::*;
 
     match event {
-        Ok(Init(time, cols, rows, _pid, seq, _text)) => Some(Ok(json_message(json!({
+        Ok(Init(time, cols, rows, _pid, seq, _text, _)) => Some(Ok(json_message(json!({
             "time": time,
             "cols": cols,
             "rows": rows,
@@ -101,7 +101,7 @@ async fn alis_message(
             format!("{cols}x{rows}")
         ])))),
 
-        Ok(Snapshot(_, _, _, _)) => None,
+        Ok(Snapshot(_, _, _, _, _)) => None,
 
         Err(e) => Some(Err(axum::Error::new(e))),
     }
@@ -158,10 +158,10 @@ async fn event_stream_message(
     use session::Event::*;
 
     match event {
-        Ok(e @ Init(_, _, _, _, _, _)) if sub.init => Some(Ok(json_message(e.to_json()))),
+        Ok(e @ Init(_, _, _, _, _, _, _)) if sub.init => Some(Ok(json_message(e.to_json()))),
         Ok(e @ Output(_, _)) if sub.output => Some(Ok(json_message(e.to_json()))),
         Ok(e @ Resize(_, _, _)) if sub.resize => Some(Ok(json_message(e.to_json()))),
-        Ok(e @ Snapshot(_, _, _, _)) if sub.snapshot => Some(Ok(json_message(e.to_json()))),
+        Ok(e @ Snapshot(_, _, _, _, _)) if sub.snapshot => Some(Ok(json_message(e.to_json()))),
         Ok(_) => None,
         Err(e) => Some(Err(axum::Error::new(e))),
     }

src/api/stdio.rs

@@ -1,4 +1,5 @@
 use super::Subscription;
+use crate::cli::StyleMode;
 use crate::command::{self, Command, InputSeq};
 use crate::session;
 use anyhow::Result;
@@ -24,10 +25,16 @@ struct ResizeArgs {
     rows: usize,
 }
 
+#[derive(Debug, Deserialize)]
+struct SetStyleModeArgs {
+    mode: String,
+}
+
 pub async fn start(
     command_tx: mpsc::Sender<Command>,
     clients_tx: mpsc::Sender<session::Client>,
     sub: Subscription,
+    _color_mode: StyleMode,
 ) -> Result<()> {
     let (input_tx, mut input_rx) = mpsc::unbounded_channel();
     thread::spawn(|| read_stdin(input_tx));
@@ -52,7 +59,7 @@ pub async fn start(
                 use session::Event::*;
 
                 match event {
-                    Some(Ok(e @ Init(_, _, _, _, _, _))) if sub.init => {
+                    Some(Ok(e @ Init(_, _, _, _, _, _, _))) if sub.init => {
                         println!("{}", e.to_json());
                     }
 
@@ -64,7 +71,7 @@ pub async fn start(
                         println!("{}", e.to_json());
                     }
 
-                    Some(Ok(e @ Snapshot(_, _, _, _))) if sub.snapshot => {
+                    Some(Ok(e @ Snapshot(_, _, _, _, _))) if sub.snapshot => {
                         println!("{}", e.to_json());
                     }
 
@@ -113,6 +120,13 @@ fn build_command(value: serde_json::Value) -> Result<Command, String> {
 
         Some("takeSnapshot") => Ok(Command::Snapshot),
 
+        Some("setStyleMode") => {
+            let args: SetStyleModeArgs = args_from_json_value(value)?;
+            let style_mode = args.mode.parse::<StyleMode>()
+                .map_err(|e| format!("invalid style mode: {}", e))?;
+            Ok(Command::SetStyleMode(style_mode))
+        }
+
         other => Err(format!("invalid command type: {other:?}")),
     }
 }
@@ -282,6 +296,7 @@ fn parse_key(key: String) -> InputSeq {
 mod test {
     use super::{cursor_key, parse_line, standard_key, Command};
     use crate::command::InputSeq;
+    use crate::cli::StyleMode;
 
     #[test]
     fn parse_input() {
@@ -483,6 +498,21 @@ mod test {
         assert!(matches!(command, Command::Snapshot));
     }
 
+    #[test]
+    fn parse_set_style_mode() {
+        let command = parse_line(r#"{ "type": "setStyleMode", "mode": "styled" }"#).unwrap();
+        assert!(matches!(command, Command::SetStyleMode(StyleMode::Styled)));
+
+        let command = parse_line(r#"{ "type": "setStyleMode", "mode": "plain" }"#).unwrap();
+        assert!(matches!(command, Command::SetStyleMode(StyleMode::Plain)));
+    }
+
+    #[test]
+    fn parse_set_style_mode_invalid() {
+        parse_line(r#"{ "type": "setStyleMode", "mode": "invalid" }"#).expect_err("should fail");
+        parse_line(r#"{ "type": "setStyleMode" }"#).expect_err("should fail");
+    }
+
     #[test]
     fn parse_invalid_json() {
         parse_line("{").expect_err("should fail");

src/cli.rs

@@ -4,6 +4,25 @@ use clap::Parser;
 use nix::pty;
 use std::{fmt::Display, net::SocketAddr, ops::Deref, str::FromStr};
 
+#[derive(Debug, Clone, Copy, Default)]
+pub enum StyleMode {
+    #[default]
+    Plain,
+    Styled,
+}
+
+impl FromStr for StyleMode {
+    type Err = String;
+
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        match s.to_lowercase().as_str() {
+            "plain" => Ok(StyleMode::Plain),
+            "styled" => Ok(StyleMode::Styled),
+            _ => Err(format!("invalid style mode: {s}. Valid options: plain, styled")),
+        }
+    }
+}
+
 #[derive(Debug, Parser)]
 #[clap(version, about)]
 #[command(name = "ht")]
@@ -23,6 +42,10 @@ pub struct Cli {
     /// Subscribe to events
     #[arg(long, value_name = "EVENTS")]
     pub subscribe: Option<Subscription>,
+
+    /// Style mode for snapshots
+    #[arg(short = 's', long = "style-mode", value_name = "MODE", default_value = "plain")]
+    pub style_mode: StyleMode,
 }
 
 impl Cli {

src/command.rs

@@ -1,8 +1,11 @@
+use crate::cli::StyleMode;
+
 #[derive(Debug)]
 pub enum Command {
     Input(Vec<InputSeq>),
     Snapshot,
     Resize(usize, usize),
+    SetStyleMode(StyleMode),
 }
 
 #[derive(Debug, PartialEq)]

src/main.rs

@@ -22,23 +22,24 @@ async fn main() -> Result<()> {
     let (clients_tx, clients_rx) = mpsc::channel(1);
 
     start_http_api(cli.listen, clients_tx.clone()).await?;
-    let api = start_stdio_api(command_tx, clients_tx, cli.subscribe.unwrap_or_default());
+    let api = start_stdio_api(command_tx, clients_tx, cli.subscribe.unwrap_or_default(), cli.style_mode);
     let (pid, pty) = start_pty(cli.command, &cli.size, input_rx, output_tx)?;
-    let session = build_session(&cli.size, pid);
+    let session = build_session(&cli.size, pid, cli.style_mode);
     run_event_loop(output_rx, input_tx, command_rx, clients_rx, session, api).await?;
     pty.await?
 }
 
-fn build_session(size: &cli::Size, pid: i32) -> Session {
-    Session::new(size.cols(), size.rows(), pid)
+fn build_session(size: &cli::Size, pid: i32, style_mode: cli::StyleMode) -> Session {
+    Session::new(size.cols(), size.rows(), pid, style_mode)
 }
 
 fn start_stdio_api(
     command_tx: mpsc::Sender<Command>,
     clients_tx: mpsc::Sender<session::Client>,
     sub: api::Subscription,
+    style_mode: cli::StyleMode,
 ) -> JoinHandle<Result<()>> {
-    tokio::spawn(api::stdio::start(command_tx, clients_tx, sub))
+    tokio::spawn(api::stdio::start(command_tx, clients_tx, sub, style_mode))
 }
 
 fn start_pty(
@@ -106,6 +107,10 @@ async fn run_event_loop(
                         session.resize(cols, rows);
                     }
 
+                    Some(Command::SetStyleMode(style_mode)) => {
+                        session.set_style_mode(style_mode);
+                    }
+
                     None => {
                         eprintln!("stdin closed, shutting down...");
                         break;