Add option parsing and exit code

Cargo.lock

@@ -4,6 +4,7 @@ version = "0.1.0"
 dependencies = [
  "chan 0.1.18 (registry+https://github.com/rust-lang/crates.io-index)",
  "chan-signal 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "getopts 0.2.14 (registry+https://github.com/rust-lang/crates.io-index)",
  "xcb 0.7.5 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
@@ -39,6 +40,11 @@ dependencies = [
  "libc 0.2.15 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "getopts"
+version = "0.2.14"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
 [[package]]
 name = "lazy_static"
 version = "0.1.16"

Cargo.toml

@@ -6,6 +6,7 @@ authors = ["Thomas Dy <thatsmydoing@gmail.com>"]
 [dependencies]
 chan = "0.1.18"
 chan-signal = "0.1.6"
+getopts = "0.2"
 
 [dependencies.xcb]
 version = "0.7.5"

src/main.rs

@@ -1,35 +1,77 @@
 #[macro_use]
 extern crate chan;
 extern crate chan_signal;
+extern crate getopts;
 extern crate xcb;
 
 mod atom;
 mod event;
 mod tray;
 
+use std::env;
+use std::process;
 use std::thread;
 use std::sync::Arc;
 
+const PROGRAM: &'static str = "rustray";
+const EXIT_WRONG_ARGS: i32 = 1;
+const EXIT_FAILED_CONNECT: i32 = 10;
+const EXIT_FAILED_SELECT: i32 = 11;
+
 fn main() {
+    process::exit(real_main());
+}
+
+fn real_main() -> i32 {
     let signal = chan_signal::notify(&[chan_signal::Signal::INT, chan_signal::Signal::TERM]);
+    let args: Vec<String> = env::args().collect();
+
+    let mut opts = getopts::Options::new();
+    opts.optopt("i", "icon-size", "size of the tray icons, default 20", "<size>");
+    opts.optopt("p", "position", "position of the tray, one of: top-left, top-right, bottom-left, bottom-right", "<pos>");
+    opts.optflag("h", "help", "print this help menu");
+    let matches = match opts.parse(&args[1..]) {
+        Ok(m) => m,
+        Err(f) => panic!(f.to_string())
+    };
+
+    if matches.opt_present("h") {
+        let brief = format!("Usage: {} [options]", PROGRAM);
+        print!("{}", opts.usage(&brief));
+        return 0
+    }
+    let pos = matches.opt_str("p").unwrap_or("top-left".to_string());
+    let pos = match pos.as_ref() {
+        "top-left" => tray::TOP_LEFT,
+        "top-right" => tray::TOP_RIGHT,
+        "bottom-left" => tray::BOTTOM_LEFT,
+        "bottom-right" => tray::BOTTOM_RIGHT,
+        _ => {
+            println!("Invalid position specified.");
+            return EXIT_WRONG_ARGS
+        }
+    };
+    let size = matches.opt_str("i");
+    let size = match size {
+        Some(string) => match string.parse::<u16>() {
+            Ok(size) => size,
+            Err(e) => {
+                println!("Invalid size specified, {}.", e.to_string());
+                return EXIT_WRONG_ARGS
+            }
+        },
+        None => 20
+    };
 
     if let Ok((conn, preferred)) = xcb::Connection::connect(None) {
         let conn = Arc::new(conn);
         let atoms = atom::Atoms::new(&conn);
 
-        let dir = "top-right";
-        let dir = match dir {
-            "top-right" => tray::TOP_RIGHT,
-            "bottom-left" => tray::BOTTOM_LEFT,
-            "bottom-right" => tray::BOTTOM_RIGHT,
-            _ => tray::TOP_LEFT
-        };
-
-        let mut tray = tray::Tray::new(&conn, &atoms, preferred as usize, 20, dir);
+        let mut tray = tray::Tray::new(&conn, &atoms, preferred as usize, size, pos);
 
         if !tray.is_selection_available() {
             println!("Another system tray is already running");
-            return
+            return EXIT_FAILED_SELECT
         }
 
         let (tx, rx) = chan::sync::<event::Event>(0);
@@ -49,7 +91,7 @@ fn main() {
                     Ready(timestamp) => {
                         if !tray.take_selection(timestamp) {
                             println!("Could not take ownership of tray selection. Maybe another tray is also running?");
-                            return
+                            return EXIT_FAILED_SELECT
                         }
                     },
                     ChildRequest(window) => {
@@ -70,8 +112,10 @@ fn main() {
 
         // cleanup code
         tray.cleanup();
+        return 0
     }
     else {
         println!("Could not connect to X server!");
+        return EXIT_FAILED_CONNECT
     }
 }