Initial commit: niri workspaces waybar module in Rust

Fast workspace visualization for waybar with:
- Color-coded windows by app (Chrome, Discord, Firefox, etc.)
- Terminal detection (Claude, Codex, nvim) via /proc
- Dimmed colors for unfocused workspaces
- Active window indicator (▌) for would-be-focused windows
- Parallel niri IPC calls for ~12ms execution time

1 files changed, 248 insertions, 0 deletions

diff --git a/src/main.rs b/src/main.rs
new file mode 100644
index 0000000..eb420de
--- /dev/null
+++ b/src/main.rs
@@ -0,0 +1,248 @@
+use serde::Deserialize;
+use std::collections::HashMap;
+use std::fs;
+use std::process::Command;
+
+#[derive(Deserialize)]
+struct Workspace {
+    id: i64,
+    idx: i32,
+    is_focused: bool,
+    active_window_id: Option<i64>,
+}
+
+#[derive(Deserialize)]
+struct Window {
+    id: i64,
+    workspace_id: i64,
+    app_id: String,
+    title: String,
+    is_focused: bool,
+    pid: Option<u32>,
+}
+
+fn main() {
+    // Get data from niri in parallel
+    let ws_handle = std::thread::spawn(|| {
+        Command::new("niri")
+            .args(["msg", "-j", "workspaces"])
+            .output()
+            .ok()
+            .and_then(|o| String::from_utf8(o.stdout).ok())
+    });
+
+    let win_handle = std::thread::spawn(|| {
+        Command::new("niri")
+            .args(["msg", "-j", "windows"])
+            .output()
+            .ok()
+            .and_then(|o| String::from_utf8(o.stdout).ok())
+    });
+
+    let (workspaces_json, windows_json) = match (ws_handle.join().ok().flatten(), win_handle.join().ok().flatten()) {
+        (Some(w), Some(win)) => (w, win),
+        _ => {
+            println!(r#"{{"text": "", "tooltip": "niri not running"}}"#);
+            return;
+        }
+    };
+
+    let mut workspaces: Vec<Workspace> = serde_json::from_str(&workspaces_json).unwrap_or_default();
+    let windows: Vec<Window> = serde_json::from_str(&windows_json).unwrap_or_default();
+
+    workspaces.sort_by_key(|w| w.idx);
+
+    // Pre-compute terminal apps by checking /proc
+    let terminal_apps: HashMap<u32, &str> = windows
+        .iter()
+        .filter(|w| is_terminal(&w.app_id))
+        .filter_map(|w| w.pid)
+        .map(|pid| (pid, detect_terminal_app(pid)))
+        .filter(|(_, app)| !app.is_empty())
+        .collect();
+
+    let mut before_focused: Vec<String> = Vec::new();
+    let mut after_focused: Vec<String> = Vec::new();
+    let mut focused_output = String::new();
+    let mut current_section = "before";
+    let mut chrome_idx = 0;
+    let mut tooltip = String::new();
+
+    for ws in &workspaces {
+        let mut ws_windows: Vec<&Window> = windows
+            .iter()
+            .filter(|w| w.workspace_id == ws.id)
+            .collect();
+
+        ws_windows.sort_by_key(|w| w.id);
+
+        let win_count = ws_windows.len();
+        tooltip.push_str(&format!("ws{}: {} windows\\n", ws.idx, win_count));
+
+        let ws_output = if win_count == 0 {
+            if ws.is_focused {
+                "<span color='#888888'>█</span>".to_string()
+            } else {
+                "<span color='#444444'>·</span>".to_string()
+            }
+        } else {
+            let mut output = String::new();
+            for win in &ws_windows {
+                let mut color = get_color(&win.app_id, &win.title, win.pid, &terminal_apps);
+
+                if color == "chrome" {
+                    const CHROME_COLORS: [&str; 4] = ["#ea4335", "#fbbc05", "#34a853", "#4285f4"];
+                    color = CHROME_COLORS[chrome_idx % 4].to_string();
+                    chrome_idx += 1;
+                }
+
+                if !ws.is_focused {
+                    color = dim_color(&color);
+                }
+
+                let bar = if win.is_focused {
+                    "█"
+                } else if !ws.is_focused && Some(win.id) == ws.active_window_id {
+                    "▌"
+                } else {
+                    "|"
+                };
+
+                output.push_str(&format!("<span color='{}'>{}</span>", color, bar));
+            }
+            output
+        };
+
+        if ws.is_focused {
+            focused_output = ws_output;
+            current_section = "after";
+        } else if current_section == "before" {
+            before_focused.push(ws_output);
+        } else {
+            after_focused.push(ws_output);
+        }
+    }
+
+    let mut output = String::new();
+    for ws in &before_focused {
+        output.push_str(ws);
+        output.push_str("  ");
+    }
+    output.push_str(&focused_output);
+    for ws in &after_focused {
+        output.push_str("  ");
+        output.push_str(ws);
+    }
+
+    if tooltip.ends_with("\\n") {
+        tooltip.truncate(tooltip.len() - 2);
+    }
+
+    println!(r#"{{"text": "{}", "tooltip": "{}"}}"#, output, tooltip);
+}
+
+fn is_terminal(app_id: &str) -> bool {
+    app_id == "Alacritty" || app_id == "kitty" || app_id == "com.mitchellh.ghostty"
+}
+
+fn detect_terminal_app(pid: u32) -> &'static str {
+    if let Ok(children) = get_all_descendants(pid) {
+        for child_pid in children {
+            if let Ok(cmdline) = fs::read_to_string(format!("/proc/{}/cmdline", child_pid)) {
+                let cmdline = cmdline.to_lowercase();
+                if cmdline.contains("claude") {
+                    return "claude";
+                } else if cmdline.contains("codex") {
+                    return "codex";
+                } else if cmdline.contains("nvim") || cmdline.contains("vim") {
+                    return "nvim";
+                }
+            }
+        }
+    }
+    ""
+}
+
+fn get_all_descendants(pid: u32) -> std::io::Result<Vec<u32>> {
+    let mut descendants = Vec::new();
+    let mut to_check = vec![pid];
+
+    while let Some(current) = to_check.pop() {
+        let children_path = format!("/proc/{}/task/{}/children", current, current);
+        if let Ok(children_str) = fs::read_to_string(&children_path) {
+            for child in children_str.split_whitespace() {
+                if let Ok(child_pid) = child.parse::<u32>() {
+                    descendants.push(child_pid);
+                    to_check.push(child_pid);
+                }
+            }
+        }
+    }
+
+    Ok(descendants)
+}
+
+fn get_color(app_id: &str, title: &str, pid: Option<u32>, terminal_apps: &HashMap<u32, &str>) -> String {
+    if is_terminal(app_id) {
+        let title_lower = title.to_lowercase();
+
+        if title_lower.contains("claude") {
+            return "#f5a623".to_string();
+        } else if title_lower.contains("codex") {
+            return "#56b6c2".to_string();
+        } else if title_lower.contains("nvim") || title_lower.contains("vim") {
+            return "#98c379".to_string();
+        }
+
+        if let Some(pid) = pid {
+            if let Some(&app) = terminal_apps.get(&pid) {
+                return match app {
+                    "claude" => "#f5a623",
+                    "codex" => "#56b6c2",
+                    "nvim" => "#98c379",
+                    _ => "#888888",
+                }.to_string();
+            }
+        }
+
+        return "#888888".to_string();
+    }
+
+    if app_id.contains("nvim") {
+        return "#98c379".to_string();
+    }
+    if app_id == "google-chrome" || app_id.contains("chrome") {
+        return "chrome".to_string();
+    }
+    if app_id == "firefox" {
+        return "#ff7139".to_string();
+    }
+    if app_id == "vesktop" || app_id == "discord" {
+        return "#c678dd".to_string();
+    }
+    if app_id.contains("todoist") {
+        return "#e06c75".to_string();
+    }
+    if app_id.contains("mail.google") {
+        return "#e5c07b".to_string();
+    }
+
+    "#666666".to_string()
+}
+
+fn dim_color(hex: &str) -> String {
+    let hex = hex.trim_start_matches('#');
+    if hex.len() != 6 {
+        return format!("#{}", hex);
+    }
+
+    let r = u8::from_str_radix(&hex[0..2], 16).unwrap_or(0);
+    let g = u8::from_str_radix(&hex[2..4], 16).unwrap_or(0);
+    let b = u8::from_str_radix(&hex[4..6], 16).unwrap_or(0);
+
+    let r = ((r as u32 * 6 / 10) + 30).min(255) as u8;
+    let g = ((g as u32 * 6 / 10) + 30).min(255) as u8;
+    let b = ((b as u32 * 6 / 10) + 30).min(255) as u8;
+
+    format!("#{:02x}{:02x}{:02x}", r, g, b)
+}