Move config path into Config type

This cleans up the Config::load API significantly. Several miscellaneous
comments were also added.

src/config.rs

@@ -194,6 +194,9 @@ pub struct Config {
     /// Bindings for the mouse
     #[serde(default)]
     mouse_bindings: Vec<MouseBinding>,
+
+    /// Path where config was loaded from
+    config_path: Option<PathBuf>,
 }
 
 impl Default for Config {
@@ -206,6 +209,7 @@ impl Default for Config {
             colors: Default::default(),
             key_bindings: Vec::new(),
             mouse_bindings: Vec::new(),
+            config_path: None,
         }
     }
 }
@@ -785,7 +789,7 @@ impl Config {
     ///
     /// 1. `$HOME/.config/alacritty.yml`
     /// 2. `$HOME/.alacritty.yml`
-    pub fn load() -> Result<(Config, PathBuf)> {
+    pub fn load() -> Result<Config> {
         let home = env::var("HOME")?;
 
         // First path
@@ -849,10 +853,19 @@ impl Config {
         self.render_timer
     }
 
-    fn load_from<P: Into<PathBuf>>(path: P) -> Result<(Config, PathBuf)> {
+    pub fn path(&self) -> Option<&Path> {
+        self.config_path
+            .as_ref()
+            .map(|p| p.as_path())
+    }
+
+    fn load_from<P: Into<PathBuf>>(path: P) -> Result<Config> {
         let path = path.into();
         let raw = Config::read_file(path.as_path())?;
-        Ok((serde_yaml::from_str(&raw[..])?, path))
+        let mut config: Config = serde_yaml::from_str(&raw)?;
+        config.config_path = Some(path);
+
+        Ok(config)
     }
 
     fn read_file<P: AsRef<Path>>(path: P) -> Result<String> {
@@ -1068,7 +1081,12 @@ pub trait OnConfigReload {
 }
 
 impl Watcher {
-    pub fn new<H: OnConfigReload + Send + 'static>(path: PathBuf, mut handler: H) -> Watcher {
+    pub fn new<H, P>(path: P, mut handler: H) -> Watcher
+        where H: OnConfigReload + Send + 'static,
+              P: Into<PathBuf>
+    {
+        let path = path.into();
+
         Watcher(::util::thread::spawn_named("config watcher", move || {
             let (tx, rx) = mpsc::channel();
             let mut watcher = FileWatcher::new(tx).unwrap();
@@ -1099,7 +1117,7 @@ impl Watcher {
                     path.map(|path| {
                         if path == config_path {
                             match Config::load() {
-                                Ok((config, _)) => handler.on_config_reload(config),
+                                Ok(config) => handler.on_config_reload(config),
                                 Err(err) => err_println!("Ignoring invalid config: {}", err),
                             }
                         }

src/main.rs

@@ -74,13 +74,13 @@ mod cli;
 
 fn main() {
     // Load configuration
-    let (config, config_path) = match Config::load() {
+    let config = match Config::load() {
         // Error loading config
         Err(err) => match err {
             // Use default config when not found
             config::Error::NotFound => {
                 err_println!("Config file not found; using defaults");
-                (Config::default(), None)
+                Config::default()
             },
 
             // If there's a problem with the config file, print an error
@@ -89,23 +89,29 @@ fn main() {
         },
 
         // Successfully loaded config from file
-        Ok((config, path)) => (config, Some(path)),
+        Ok(config) => config
     };
 
+    // Load command line options
     let options = cli::Options::load();
 
+    // Extract some properties from config
     let font = config.font();
     let dpi = config.dpi();
     let render_timer = config.render_timer();
 
+    // Create glutin window
     let mut window = glutin::WindowBuilder::new()
                                            .with_vsync()
                                            .with_title("Alacritty")
                                            .build().unwrap();
 
+    // Set the glutin window resize callback for this one window.
     window.set_window_resize_callback(Some(window_resize_handler as fn(u32, u32)));
 
+    // load gl symbols
     gl::load_with(|symbol| window.get_proc_address(symbol) as *const _);
+    // get window properties for initializing the other subsytems
     let (width, height) = window.get_inner_size_pixels().unwrap();
     let dpr = window.hidpi_factor();
 
@@ -140,11 +146,14 @@ fn main() {
         cache
     };
 
+    // Need font metrics to resize the window properly. This suggests to me the
+    // font metrics should be computed before creating the window in the first
+    // place so that a resize is not needed.
     let metrics = glyph_cache.font_metrics();
     let cell_width = (metrics.average_advance + font.offset().x() as f64) as u32;
     let cell_height = (metrics.line_height + font.offset().y() as f64) as u32;
 
-    // Resize window to be 80 col x 24 lines
+    // Resize window to specified dimensions
     let width = cell_width * options.columns_u32() + 4;
     let height = cell_height * options.lines_u32() + 4;
     println!("set_inner_size: {} x {}", width, height);
@@ -225,8 +234,8 @@ fn main() {
     let (config_tx, config_rx) = mpsc::channel();
 
     // create a config watcher when config is loaded from disk
-    let _config_reloader = config_path.map(|config_path| {
-        config::Watcher::new(config_path, ConfigHandler {
+    let _config_reloader = config.path().map(|path| {
+        config::Watcher::new(path, ConfigHandler {
             tx: config_tx,
             window: window.create_window_proxy(),
         })
@@ -273,7 +282,6 @@ struct ConfigHandler {
     window: ::glutin::WindowProxy,
 }
 
-// TODO FIXME
 impl config::OnConfigReload for ConfigHandler {
     fn on_config_reload(&mut self, config: Config) {
         if let Err(..) = self.tx.send(config) {