Add spawn-at-startup config option

Fixes https://github.com/YaLTeR/niri/issues/12

resources/default-config.kdl

@@ -35,6 +35,11 @@ input {
     scale 2.0
 }
 
+// Add lines like this to spawn processes at startup.
+// Note that running niri as a session supports xdg-desktop-autostart,
+// which may be more convenient to use.
+// spawn-at-startup "alacritty" "-e" "fish"
+
 binds {
     // Keys consist of modifiers separated by + signs, followed by an XKB key name
     // in the end. To find an XKB name for a particular key, you may use a program

src/config.rs

@@ -13,6 +13,8 @@ pub struct Config {
     pub input: Input,
     #[knuffel(children(name = "output"))]
     pub outputs: Vec<Output>,
+    #[knuffel(children(name = "spawn-at-startup"))]
+    pub spawn_at_startup: Vec<SpawnAtStartup>,
     #[knuffel(child, default)]
     pub binds: Binds,
     #[knuffel(child, default)]
@@ -81,6 +83,12 @@ impl Default for Output {
     }
 }
 
+#[derive(knuffel::Decode, Debug, Clone, PartialEq, Eq)]
+pub struct SpawnAtStartup {
+    #[knuffel(arguments)]
+    pub command: Vec<String>,
+}
+
 #[derive(knuffel::Decode, Debug, Default, PartialEq, Eq)]
 pub struct Binds(#[knuffel(children)] pub Vec<Bind>);
 
@@ -286,6 +294,8 @@ mod tests {
                 scale 2.0
             }
 
+            spawn-at-startup "alacritty" "-e" "fish"
+
             binds {
                 Mod+T { spawn "alacritty"; }
                 Mod+Q { close-window; }
@@ -320,6 +330,9 @@ mod tests {
                     name: "eDP-1".to_owned(),
                     scale: 2.,
                 }],
+                spawn_at_startup: vec![SpawnAtStartup {
+                    command: vec!["alacritty".to_owned(), "-e".to_owned(), "fish".to_owned()],
+                }],
                 binds: Binds(vec![
                     Bind {
                         key: Key {

src/main.rs

@@ -13,9 +13,9 @@ mod niri;
 mod pw_utils;
 mod utils;
 
-use std::env;
 use std::ffi::OsString;
 use std::path::PathBuf;
+use std::{env, mem};
 
 use clap::Parser;
 use config::Config;
@@ -57,7 +57,7 @@ fn main() {
 
     let _client = tracy_client::Client::start();
 
-    let config = match Config::load(cli.config).context("error loading config") {
+    let mut config = match Config::load(cli.config).context("error loading config") {
         Ok(config) => config,
         Err(err) => {
             warn!("{err:?}");
@@ -65,6 +65,7 @@ fn main() {
         }
     };
     animation::ANIMATION_SLOWDOWN.store(config.debug.animation_slowdown, Ordering::Relaxed);
+    let spawn_at_startup = mem::take(&mut config.spawn_at_startup);
 
     let mut event_loop = EventLoop::try_new().unwrap();
     let mut display = Display::new().unwrap();
@@ -76,10 +77,17 @@ fn main() {
     );
     let mut data = LoopData { display, state };
 
+    // Spawn commands from cli and auto-start.
     if let Some((command, args)) = cli.command.split_first() {
         spawn(command, args);
     }
 
+    for elem in spawn_at_startup {
+        if let Some((command, args)) = elem.command.split_first() {
+            spawn(command, args);
+        }
+    }
+
     event_loop
         .run(None, &mut data, move |data| {
             let _span = tracy_client::span!("loop callback");