Honor bread.command.shot.region via breadshot listen

Pin bread-utils to bread-ecosystem v0.7.2. breadshot listen
subscribes to bread.command.shot.**, runs the same region capture
as the CLI (clipboard-only), and emits bread.shot.region.done /
.failed.

src/capture.rs

@@ -1,5 +1,4 @@
 use anyhow::{bail, Context, Result};
-use clap::ValueEnum;
 use serde_json::Value;
 use std::{
     io::Write,
@@ -12,9 +11,9 @@ use crate::config::Config;
 
 /// Sibling-app id in bread's `KNOWN_APPS` registry. Events publish as
 /// `bread.shot.*`. See `EVENTS.md`.
-const APP_ID: &str = "shot";
+pub(crate) const APP_ID: &str = "shot";
 
-#[derive(Debug, Clone, ValueEnum)]
+#[derive(Debug, Clone)]
 pub enum Mode {
     /// Select a region interactively
     Region,
@@ -23,10 +22,8 @@ pub enum Mode {
     /// Click to select a monitor
     Output,
     /// Capture the active window
-    #[value(name = "active-window")]
     ActiveWindow,
     /// Capture the active monitor
-    #[value(name = "active-output")]
     ActiveOutput,
 }
 
@@ -353,8 +350,12 @@ fn send_notification(title: &str, msg: &str, timeout: u32, path: &Path) {
 
 fn hyprctl_json(subcmd: &str) -> Result<Value> {
     // Was a bare Command::new("hyprctl").output() with no timeout.
-    bread_utils::proc::run_json("hyprctl", &["-j", subcmd], std::time::Duration::from_secs(3))
-        .with_context(|| format!("running/parsing hyprctl {subcmd}"))
+    bread_utils::proc::run_json(
+        "hyprctl",
+        &["-j", subcmd],
+        std::time::Duration::from_secs(3),
+    )
+    .with_context(|| format!("running/parsing hyprctl {subcmd}"))
 }
 
 fn slurp(args: &[&str]) -> Result<String> {

src/listen.rs

@@ -0,0 +1,110 @@
+//! Long-running command subscription for `bread.command.shot.*`.
+//!
+//! `breadshot` is still a one-shot CLI by default. `breadshot listen` is the
+//! optional persistent process that can honor bus commands. See `EVENTS.md`.
+
+use anyhow::Result;
+use bread_utils::bread_client::{BreadClient, BreadEvent};
+
+use crate::capture::{self, Mode, Overrides, APP_ID};
+use crate::config::Config;
+
+/// Subscribe to `bread.command.shot.**` and block until the process is killed.
+///
+/// breadd being absent is not an error: [`BreadClient::subscribe`] reconnects
+/// with backoff, and `on_event` simply isn't called until the daemon is up.
+pub fn run(config: &Config) -> Result<()> {
+    let client = BreadClient::connect(APP_ID);
+    if client.health().is_none() {
+        tracing::warn!("breadd unreachable; command subscription will connect when it comes back");
+    }
+
+    let config = config.clone();
+    let _commands = client.subscribe("bread.command.shot.**", move |event| {
+        handle_command(&event, &config);
+    });
+
+    tracing::info!("listening for bread.command.shot.**");
+    loop {
+        std::thread::park();
+    }
+}
+
+/// Reacts to `bread.command.shot.*` verbs. Only `region` is honored today —
+/// other verbs are ignored, not stubbed as no-ops that pretend to succeed.
+///
+/// Emits `bread.shot.region.done` / `.failed` per the confirmation convention
+/// in bread's Documentation.md.
+fn handle_command(event: &BreadEvent, config: &Config) {
+    let Some(verb) = command_verb(&event.event) else {
+        return;
+    };
+    match verb {
+        "region" => handle_region(config),
+        other => {
+            tracing::debug!("ignoring unrecognized command verb '{other}'");
+        }
+    }
+}
+
+fn handle_region(config: &Config) {
+    // Clipboard-only matches the default region *bus* path: a Lua workflow
+    // that wants a file on disk can still `bread.exec("breadshot region")`.
+    let result = capture::run(
+        &Mode::Region,
+        config,
+        Overrides {
+            clipboard_only: true,
+            silent: false,
+            freeze: false,
+            output_dir: None,
+            filename: None,
+        },
+    );
+    let client = BreadClient::connect(APP_ID);
+    match result {
+        Ok(()) => client.emit("bread.shot.region.done", region_done_payload()),
+        Err(e) => {
+            tracing::warn!("bread.command.shot.region failed: {e}");
+            client.emit("bread.shot.region.failed", region_failed_payload(&e));
+        }
+    }
+}
+
+fn command_verb(event_name: &str) -> Option<&str> {
+    event_name.strip_prefix("bread.command.shot.")
+}
+
+fn region_done_payload() -> serde_json::Value {
+    serde_json::json!({ "clipboard": true, "path": serde_json::Value::Null })
+}
+
+fn region_failed_payload(error: &impl ToString) -> serde_json::Value {
+    serde_json::json!({ "error": error.to_string() })
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn command_verb_strips_shot_prefix() {
+        assert_eq!(command_verb("bread.command.shot.region"), Some("region"));
+        assert_eq!(command_verb("bread.command.shot.window"), Some("window"));
+        assert_eq!(command_verb("bread.command.clip.clear"), None);
+        assert_eq!(command_verb("bread.shot.captured"), None);
+    }
+
+    #[test]
+    fn region_done_payload_is_clipboard_only() {
+        let v = region_done_payload();
+        assert_eq!(v["clipboard"], true);
+        assert!(v["path"].is_null());
+    }
+
+    #[test]
+    fn region_failed_payload_includes_error() {
+        let v = region_failed_payload(&"selection cancelled");
+        assert_eq!(v["error"], "selection cancelled");
+    }
+}

src/main.rs

@@ -1,8 +1,9 @@
 mod capture;
 mod config;
+mod listen;
 
 use anyhow::Result;
-use clap::Parser;
+use clap::{Args, Parser, Subcommand};
 use std::path::PathBuf;
 use tracing_subscriber::EnvFilter;
 
@@ -14,12 +15,19 @@ use config::Config;
     name = "breadshot",
     version,
     about = "Screenshot utility for the bread ecosystem",
-    disable_help_subcommand = true,
+    disable_help_subcommand = true
 )]
 struct Cli {
-    /// Capture mode
-    mode: Mode,
+    #[command(subcommand)]
+    command: Command,
 
+    /// Path to config file
+    #[arg(long, value_name = "FILE", global = true)]
+    config: Option<PathBuf>,
+}
+
+#[derive(Args)]
+struct CaptureOpts {
     /// Copy to clipboard only, don't save to disk
     #[arg(long, short = 'c')]
     clipboard_only: bool,
@@ -39,10 +47,37 @@ struct Cli {
     /// Override output filename (without path)
     #[arg(long, short = 'f', value_name = "NAME")]
     filename: Option<String>,
+}
 
-    /// Path to config file
-    #[arg(long, value_name = "FILE")]
-    config: Option<PathBuf>,
+#[derive(Subcommand)]
+enum Command {
+    /// Select a region interactively
+    Region(CaptureOpts),
+    /// Click to select a window
+    Window(CaptureOpts),
+    /// Click to select a monitor
+    Output(CaptureOpts),
+    /// Capture the active window
+    #[command(name = "active-window")]
+    ActiveWindow(CaptureOpts),
+    /// Capture the active monitor
+    #[command(name = "active-output")]
+    ActiveOutput(CaptureOpts),
+    /// Subscribe to bread.command.shot.** and honor region captures
+    Listen,
+}
+
+impl Command {
+    fn into_capture(self) -> Option<(Mode, CaptureOpts)> {
+        match self {
+            Self::Region(opts) => Some((Mode::Region, opts)),
+            Self::Window(opts) => Some((Mode::Window, opts)),
+            Self::Output(opts) => Some((Mode::Output, opts)),
+            Self::ActiveWindow(opts) => Some((Mode::ActiveWindow, opts)),
+            Self::ActiveOutput(opts) => Some((Mode::ActiveOutput, opts)),
+            Self::Listen => None,
+        }
+    }
 }
 
 fn main() -> Result<()> {
@@ -58,15 +93,19 @@ fn main() -> Result<()> {
         None => Config::load()?,
     };
 
+    let Some((mode, opts)) = cli.command.into_capture() else {
+        return listen::run(&config);
+    };
+
     capture::run(
-        &cli.mode,
+        &mode,
         &config,
         Overrides {
-            clipboard_only: cli.clipboard_only,
-            silent: cli.silent,
-            freeze: cli.freeze,
-            output_dir: cli.output_dir,
-            filename: cli.filename,
+            clipboard_only: opts.clipboard_only,
+            silent: opts.silent,
+            freeze: opts.freeze,
+            output_dir: opts.output_dir,
+            filename: opts.filename,
         },
     )
 }