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.

Cargo.lock

@@ -95,8 +95,8 @@ dependencies = [
 
 [[package]]
 name = "bread-utils"
-version = "0.3.1"
+version = "0.7.2"
-source = "git+https://git.breadway.dev/Breadway/bread-ecosystem?tag=v0.7.1#db2fa3c4b4c1e6933bc5cf62a236d05972fdc886"
+source = "git+https://git.breadway.dev/Breadway/bread-ecosystem?tag=v0.7.2#30517f161724132cdeb658c04cf5e490be07ee73"
 dependencies = [
  "bread-shared",
  "dirs",

Cargo.toml

@@ -16,7 +16,7 @@ serde_json = "1"
 toml = "0.8"
 tracing = "0.1"
 tracing-subscriber = { version = "0.3", features = ["env-filter"] }
-bread-utils = { git = "https://git.breadway.dev/Breadway/bread-ecosystem", tag = "v0.7.1", features = ["bread-client"] }
+bread-utils = { git = "https://git.breadway.dev/Breadway/bread-ecosystem", tag = "v0.7.2", features = ["bread-client"] }
 
 [profile.release]
 lto = "thin"

EVENTS.md

@@ -1,33 +1,37 @@
 # breadshot — bread event integration
 
-breadshot is a standalone, one-shot Wayland screenshot orchestrator: it
+breadshot is a standalone Wayland screenshot orchestrator: it works
-works exactly the same with or without `breadd` running. When breadd *is*
+exactly the same with or without `breadd` running. When breadd *is*
-present, a successful capture publishes one event into the shared bread
+present, a successful capture publishes into the shared bread automation
-automation fabric. See the parent `bread` repo's `Documentation.md` —
+fabric. See the parent `bread` repo's `Documentation.md` — specifically
-specifically its "Namespaces" and "Integrating a bread\* app" sections —
+its "Namespaces" and "Integrating a bread\* app" sections — for the
-for the general convention this follows.
+general convention this follows.
 
 This is a different job from `bread-screenshots` (the crate in
 `bread-ecosystem`): that one is a capture harness for screenshotting
 sibling apps in CI. Do not merge the two.
 
 App id: **`shot`**. Transport: `bread-utils`'s `bread_client` module
-(feature `bread-client`). breadshot is a short-lived CLI, not a daemon —
+(feature `bread-client`). One-shot CLI invocations (`breadshot region`,
-each `emit` is its own fire-and-forget connection (the same stance
+…) each `emit` on their own fire-and-forget connection (the same stance
-`bread-emit` takes for occasional callers). There is no process to hold a
+`bread-emit` takes for occasional callers). Command verbs are only
-command subscription open.
+received while `breadshot listen` is running — that process holds the
+`bread.command.shot.**` subscription open.
 
 ## Events published (`bread.shot.*`)
 
 | Event | Data | When |
 |-------|------|------|
-| `bread.shot.captured` | `{ "mode": "region" \| "window" \| "output" \| "active-window" \| "active-output", "clipboard": bool, "path": <string or null> }` | A capture completed successfully (grim + clipboard write both returned). Not emitted on a cancelled slurp selection, a missing dependency, or a grim/wl-copy failure. |
+| `bread.shot.captured` | `{ "mode": "region" \| "window" \| "output" \| "active-window" \| "active-output", "clipboard": bool, "path": <string or null> }` | A capture completed successfully (grim + clipboard write both returned), whether triggered by the CLI or by `bread.command.shot.region`. Not emitted on a cancelled slurp selection, a missing dependency, or a grim/wl-copy failure. |
+| `bread.shot.region.done` | `{ "clipboard": true, "path": null }` | `bread.command.shot.region` was received and the region capture succeeded. |
+| `bread.shot.region.failed` | `{ "error": "<message>" }` | `bread.command.shot.region` was received but the capture failed (cancelled slurp, missing dependency, grim/wl-copy error). |
 
 `mode` is the CLI mode name (same strings `breadshot <mode>` accepts).
 `clipboard` is whether the PNG was written to the clipboard — both current
 capture paths do this (`save_and_copy` and `--clipboard-only`). `path` is
 the saved file, or `null` when `--clipboard-only` was used (no file on
-disk).
+disk). The listen-triggered region path is clipboard-only, so `path` is
+always `null` on `bread.shot.region.done`.
 
 The image bytes themselves are never included in the payload. The event
 bus is a notification that a capture happened, not a channel for the
@@ -35,32 +39,47 @@ screenshot.
 
 ## Commands honored (`bread.command.shot.*`)
 
-None. breadshot is a one-shot CLI with no persistent process to subscribe
+These are only received while `breadshot listen` is running. Publishing a
-to `bread.command.shot.*`. A Lua workflow that wants a screenshot should
+command with no subscriber is a silent no-op — that is the documented
-shell out:
+bread convention, not a breadshot bug.
+
+| Verb | Data | Effect |
+|------|------|--------|
+| `region` | none | Same interactive region capture as `breadshot region --clipboard-only`. Emits `bread.shot.region.done`/`.failed`. A successful capture also publishes `bread.shot.captured` the same way the CLI path does. |
+
+```lua
+bread.spawn(function()
+    bread.emit("bread.command.shot.region")
+    bread.wait("bread.shot.region.done", { timeout = 30000 })
+end)
+```
+
+A workflow that wants a file on disk (not just the clipboard) should
+still shell out:
 
 ```lua
 bread.exec("breadshot region")
--- or
-bread.exec("breadshot region --clipboard-only")
 bread.exec("breadshot active-output")
 ```
 
-The outcome of that exec is the same `bread.shot.captured` event the
+### Not implemented: extra verbs
-keybind path already publishes — `bread.wait("bread.shot.captured")`
-inside a spawned coroutine if the workflow needs to react to the file.
 
-There is no `pin`, `select`, `edit`, or other command verb. breadshot has
+There is no `window`, `output`, `active-window`, `active-output`, `pin`,
-no editor, no history, and no concept those verbs could hang on.
+`select`, or `edit` command verb. The CLI already covers the other
-`bread.exec("breadshot …")` is the whole command surface. If/when a
+capture modes as synchronous one-shots, and breadshot has no editor, no
-long-running piece exists, verbs should be added then, not stubbed as
+history, and no concept those other verbs could hang on. If/when that
-no-ops ahead of it.
+changes, the corresponding `bread.command.shot.*` verb should be added
+at the same time, not stubbed as a no-op ahead of it.
 
 ## Fail-safe behavior
 
 - If breadd isn't installed or isn't running, `emit` is a silent no-op
-  (`BreadClient::emit` never blocks or errors the caller) — breadshot's
+  (`BreadClient::emit` never blocks or errors the caller) and the
+  command subscription simply never receives anything — breadshot's
   actual grim/slurp/wl-copy path is entirely unaffected either way.
-- There is no command subscription, so a breadd restart cannot drop one.
+- If breadd restarts, the command subscription reconnects automatically
-  The next `breadshot` invocation emits (or silently doesn't) on its own
+  (`BreadClient::subscribe`'s background thread has its own backoff
-  short-lived connection.
+  loop); no restart of `breadshot listen` is needed.
+- If `breadshot listen` is not running, commands are a graceful no-op at
+  the bus (no subscriber). The CLI still works, and one-shot invocations
+  still emit `bread.shot.captured` on their own short-lived connection.

README.md

@@ -47,8 +47,14 @@ make install PREFIX=/usr
 
 ```
 breadshot <mode> [options]
+breadshot listen
 ```
 
+`breadshot listen` is the long-running process that honors
+`bread.command.shot.region` on the bread event bus (clipboard-only
+region capture). See [EVENTS.md](EVENTS.md). Without it, the CLI still
+works; bus commands are a silent no-op.
+
 ### Modes
 
 | Mode | Description |

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,
 }
 
@@ -353,7 +350,11 @@ 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))
+    bread_utils::proc::run_json(
+        "hyprctl",
+        &["-j", subcmd],
+        std::time::Duration::from_secs(3),
+    )
     .with_context(|| format!("running/parsing hyprctl {subcmd}"))
 }
 

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
+    #[command(subcommand)]
-    mode: Mode,
+    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
+#[derive(Subcommand)]
-    #[arg(long, value_name = "FILE")]
+enum Command {
-    config: Option<PathBuf>,
+    /// 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,
+            clipboard_only: opts.clipboard_only,
-            silent: cli.silent,
+            silent: opts.silent,
-            freeze: cli.freeze,
+            freeze: opts.freeze,
-            output_dir: cli.output_dir,
+            output_dir: opts.output_dir,
-            filename: cli.filename,
+            filename: opts.filename,
         },
     )
 }