Show filename and dir in header bar

src/main.rs

@@ -48,6 +48,7 @@ mod popup_menu;
 mod project;
 mod tabline;
 mod error;
+mod subscriptions;
 
 use std::env;
 use std::time::Duration;

src/nvim/handler.rs

@@ -83,6 +83,12 @@ impl NvimHandler {
                     error!("Unsupported event {:?}", params);
                 }
             }
+            "subscription" => {
+                self.safe_call(move |ui| {
+                    let ui = &ui.borrow();
+                    ui.notify(params)
+                });
+            }
             _ => {
                 error!("Notification {}({:?})", method, params);
             }

src/project.rs

@@ -59,7 +59,7 @@ pub struct Projects {
 }
 
 impl Projects {
-    pub fn new(ref_widget: &gtk::ToolButton, shell: Rc<RefCell<Shell>>) -> Rc<RefCell<Projects>> {
+    pub fn new(ref_widget: &gtk::Button, shell: Rc<RefCell<Shell>>) -> Rc<RefCell<Projects>> {
         let projects = Projects {
             shell,
             popup: Popover::new(Some(ref_widget)),

src/shell.rs

@@ -33,6 +33,7 @@ use error;
 use mode;
 use render;
 use render::CellMetrics;
+use subscriptions::{Subscriptions, SubscriptionHandle};
 
 const DEFAULT_FONT_NAME: &str = "DejaVu Sans Mono 12";
 pub const MINIMUM_SUPPORTED_NVIM_VERSION: &str = "0.2.2";
@@ -78,6 +79,8 @@ pub struct State {
 
     detach_cb: Option<Box<RefCell<FnMut() + Send + 'static>>>,
     nvim_started_cb: Option<Box<RefCell<FnMut() + Send + 'static>>>,
+
+    subscriptions: RefCell<Subscriptions>,
 }
 
 impl State {
@@ -116,6 +119,8 @@ impl State {
 
             detach_cb: None,
             nvim_started_cb: None,
+
+            subscriptions: RefCell::new(Subscriptions::new()),
         }
     }
 
@@ -328,6 +333,25 @@ impl State {
             };
         }
     }
+
+    pub fn subscribe<F>(&self, event_name: &str, args: &[&str], cb: F) -> SubscriptionHandle
+    where
+        F: Fn(Vec<String>) + 'static,
+    {
+        self.subscriptions.borrow_mut().subscribe(event_name, args, cb)
+    }
+
+    pub fn set_autocmds(&self) {
+        self.subscriptions.borrow().set_autocmds(&mut self.nvim().unwrap());
+    }
+
+    pub fn notify(&self, params: Vec<Value>) -> Result<(), String> {
+        self.subscriptions.borrow().notify(params)
+    }
+
+    pub fn run_now(&self, handle: &SubscriptionHandle) {
+        self.subscriptions.borrow().run_now(handle, &mut self.nvim().unwrap());
+    }
 }
 
 pub struct UiState {
@@ -574,6 +598,15 @@ impl Shell {
         }
     }
 
+    pub fn new_tab(&self) {
+        let state = self.state.borrow();
+
+        let nvim = state.nvim();
+        if let Some(mut nvim) = nvim {
+            nvim.command(":tabe").report_err();
+        }
+    }
+
     pub fn set_detach_cb<F>(&self, cb: Option<F>)
     where
         F: FnMut() + Send + 'static,

src/subscriptions.rs

@@ -0,0 +1,158 @@
+use std::collections::HashMap;
+
+use neovim_lib::{NeovimApi, Value};
+
+use nvim::NeovimRef;
+
+/// A subscription to a Neovim autocmd event.
+struct Subscription {
+    /// A callback to be executed each time the event triggers.
+    cb: Box<Fn(Vec<String>) + 'static>,
+    /// A list of expressions which will be evaluated when the event triggers. The result is passed
+    /// to the callback.
+    args: Vec<String>,
+}
+
+/// A map of all registered subscriptions.
+pub struct Subscriptions(HashMap<String, Vec<Subscription>>);
+
+/// A handle to identify a `Subscription` within the `Subscriptions` map.
+///
+/// Can be used to trigger the subscription manually even when the event was not triggered.
+///
+/// Could be used in the future to suspend individual subscriptions.
+#[derive(Debug)]
+pub struct SubscriptionHandle {
+    event_name: String,
+    index: usize,
+}
+
+impl Subscriptions {
+    pub fn new() -> Self {
+        Subscriptions(HashMap::new())
+    }
+
+    /// Subscribe to a Neovim autocmd event.
+    ///
+    /// Subscriptions are not active immediately but only after `set_autocmds` is called. At the
+    /// moment, all calls to `subscribe` must be made before calling `set_autocmds`.
+    ///
+    /// This function is wrapped by `shell::State`.
+    ///
+    /// # Arguments:
+    ///
+    /// - `event_name`: The event to register.
+    ///   See `:help autocmd-events` for a list of supported event names. Event names can be
+    ///   comma-separated.
+    ///
+    /// - `args`: A list of expressions to be evaluated when the event triggers.
+    ///   Expressions are evaluated using Vimscript. The results are passed to the callback as a
+    ///   list of Strings.
+    ///   This is especially useful as `Neovim::eval` is synchronous and might block if called from
+    ///   the callback function; so always use the `args` mechanism instead.
+    ///
+    /// - `cb`: The callback function.
+    ///   This will be called each time the event triggers or when `run_now` is called.
+    ///   It is passed a vector with the results of the evaluated expressions given with `args`.
+    ///
+    /// # Example
+    ///
+    /// Call a function each time a buffer is entered or the current working directory is changed.
+    /// Pass the current buffer name and directory to the callback.
+    /// ```
+    /// let my_subscription = shell.state.borrow()
+    ///     .subscribe("BufEnter,DirChanged", &["expand(@%)", "getcwd()"], move |args| {
+    ///         let filename = &args[0];
+    ///         let dir = &args[1];
+    ///         // do stuff
+    ///     });
+    /// ```
+    pub fn subscribe<F>(&mut self, event_name: &str, args: &[&str], cb: F) -> SubscriptionHandle
+    where
+        F: Fn(Vec<String>) + 'static,
+    {
+        let entry = self.0.entry(event_name.to_owned()).or_insert(Vec::new());
+        let index = entry.len();
+        entry.push(Subscription {
+            cb: Box::new(cb),
+            args: args.into_iter().map(|&s| s.to_owned()).collect(),
+        });
+        SubscriptionHandle {
+            event_name: event_name.to_owned(),
+            index,
+        }
+    }
+
+    /// Register all subscriptions with Neovim.
+    ///
+    /// This function is wrapped by `shell::State`.
+    pub fn set_autocmds(&self, nvim: &mut NeovimRef) {
+        for (event_name, subscriptions) in &self.0 {
+            for (i, subscription) in subscriptions.iter().enumerate() {
+                let args = subscription.args
+                    .iter()
+                    .fold("".to_owned(), |acc, arg| acc + ", " + &arg);
+                nvim.command(&format!(
+                    "au {} * call rpcnotify(1, 'subscription', '{}', {} {})",
+                    event_name,
+                    event_name,
+                    i,
+                    args,
+                )).expect("Could not set autocmd");
+            }
+        }
+    }
+
+    /// Trigger given event.
+    fn on_notify(&self, event_name: &str, index: usize, args: Vec<String>) {
+        if let Some(subscription) = self.0.get(event_name).and_then(|v| v.get(index)) {
+            (*subscription.cb)(args);
+        }
+    }
+
+    /// Wrapper around `on_notify` for easy calling with a `neovim_lib::Handler` implementation.
+    ///
+    /// This function is wrapped by `shell::State`.
+    pub fn notify(&self, params: Vec<Value>) -> Result<(), String> {
+        let mut params_iter = params.into_iter();
+        let ev_name = params_iter.next();
+        let ev_name = ev_name
+            .as_ref()
+            .and_then(Value::as_str)
+            .ok_or("Error reading event name")?;
+        let index = params_iter
+            .next()
+            .and_then(|i| i.as_u64())
+            .ok_or("Error reading index")? as usize;
+        let args = params_iter
+            .map(|arg| arg.as_str().map(|s| s.to_owned()))
+            .collect::<Option<Vec<String>>>()
+            .ok_or("Error reading args")?;
+        self.on_notify(ev_name, index, args);
+        Ok(())
+    }
+
+    /// Manually trigger the given subscription.
+    ///
+    /// The `nvim` instance is needed to evaluate the `args` expressions.
+    ///
+    /// This function is wrapped by `shell::State`.
+    pub fn run_now(&self, handle: &SubscriptionHandle, nvim: &mut NeovimRef) {
+        let subscription = &self.0.get(&handle.event_name).unwrap()[handle.index];
+        let args = subscription.args
+            .iter()
+            .map(|arg| nvim.eval(arg))
+            .map(|res| {
+                res.ok()
+                    .and_then(|val| {
+                        val.as_str().map(|s: &str| s.to_owned())
+                    })
+            })
+            .collect::<Option<Vec<String>>>();
+        if let Some(args) = args {
+            self.on_notify(&handle.event_name, handle.index, args);
+        } else {
+            error!("Error manually running {:?}", handle);
+        }
+    }
+}

src/ui.rs

@@ -1,13 +1,13 @@
 use std::cell::{Ref, RefCell, RefMut};
 use std::{env, thread};
+use std::path::Path;
 use std::rc::Rc;
 use std::sync::Arc;
 
 use gdk;
 use gtk;
-use gtk_sys;
 use gtk::prelude::*;
-use gtk::{AboutDialog, ApplicationWindow, HeaderBar, Image, SettingsExt, ToolButton};
+use gtk::{AboutDialog, ApplicationWindow, Button, HeaderBar, SettingsExt};
 use gio::prelude::*;
 use gio::{Menu, MenuExt, MenuItem, SimpleAction};
 use toml;
@@ -17,6 +17,7 @@ use shell::{self, Shell, ShellOptions};
 use shell_dlg;
 use project::Projects;
 use plug_manager;
+use subscriptions::SubscriptionHandle;
 
 macro_rules! clone {
     (@param _) => ( _ );
@@ -50,16 +51,22 @@ pub struct Ui {
 pub struct Components {
     window: Option<ApplicationWindow>,
     window_state: WindowState,
-    open_btn: ToolButton,
+    open_btn: Button,
 }
 
 impl Components {
     fn new() -> Components {
-        let save_image =
+        let open_btn = Button::new();
-            Image::new_from_icon_name("document-open", gtk_sys::GTK_ICON_SIZE_SMALL_TOOLBAR as i32);
+        let open_btn_box = gtk::Box::new(gtk::Orientation::Horizontal, 3);
-
+        open_btn_box.pack_start(&gtk::Label::new("Open"), false, false, 3);
+        open_btn_box.pack_start(
+            &gtk::Image::new_from_icon_name("pan-down-symbolic", gtk::IconSize::Menu.into()),
+            false, false, 3
+        );
+        open_btn.add(&open_btn_box);
+        open_btn.set_can_focus(false);
         Components {
-            open_btn: ToolButton::new(Some(&save_image), "Open"),
+            open_btn,
             window: None,
             window_state: WindowState::load(),
         }
@@ -126,48 +133,6 @@ impl Ui {
                 }
             }
 
-            // Client side decorations including the toolbar are disabled via NVIM_GTK_NO_HEADERBAR=1
-            let use_header_bar = env::var("NVIM_GTK_NO_HEADERBAR")
-                .map(|opt| opt.trim() != "1")
-                .unwrap_or(true);
-
-            if app.prefers_app_menu() || use_header_bar {
-                self.create_main_menu(app, &window);
-            }
-
-            if use_header_bar {
-                let header_bar = HeaderBar::new();
-
-                let projects = self.projects.clone();
-                header_bar.pack_start(&comps.open_btn);
-                comps
-                    .open_btn
-                    .connect_clicked(move |_| projects.borrow_mut().show());
-
-                let save_image = Image::new_from_icon_name(
-                    "document-save",
-                    gtk_sys::GTK_ICON_SIZE_SMALL_TOOLBAR as i32,
-                );
-                let save_btn = ToolButton::new(Some(&save_image), "Save");
-
-                let shell = self.shell.clone();
-                save_btn.connect_clicked(move |_| shell.borrow_mut().edit_save_all());
-                header_bar.pack_start(&save_btn);
-
-                let paste_image = Image::new_from_icon_name(
-                    "edit-paste",
-                    gtk_sys::GTK_ICON_SIZE_SMALL_TOOLBAR as i32,
-                );
-                let paste_btn = ToolButton::new(Some(&paste_image), "Paste");
-                let shell = self.shell.clone();
-                paste_btn.connect_clicked(move |_| shell.borrow_mut().edit_paste());
-                header_bar.pack_start(&paste_btn);
-
-                header_bar.set_show_close_button(true);
-
-                window.set_titlebar(Some(&header_bar));
-            }
-
             if restore_win_state {
                 if comps.window_state.is_maximized {
                     window.maximize();
@@ -182,6 +147,21 @@ impl Ui {
             }
         }
 
+        // Client side decorations including the toolbar are disabled via NVIM_GTK_NO_HEADERBAR=1
+        let use_header_bar = env::var("NVIM_GTK_NO_HEADERBAR")
+            .map(|opt| opt.trim() != "1")
+            .unwrap_or(true);
+
+        if app.prefers_app_menu() || use_header_bar {
+            self.create_main_menu(app, &window);
+        }
+
+        let update_subtitle = if use_header_bar {
+            Some(self.create_header_bar())
+        } else {
+            None
+        };
+
         let comps_ref = self.comps.clone();
         window.connect_size_allocate(move |window, _| {
             gtk_window_size_allocate(window, &mut *comps_ref.borrow_mut())
@@ -202,7 +182,27 @@ impl Ui {
         window.add(&**shell);
 
         window.show_all();
-        window.set_title("NeovimGtk");
+
+        let comps_ref = self.comps.clone();
+        let update_title = shell.state.borrow()
+            .subscribe("BufEnter,DirChanged", &["expand('%:p')", "getcwd()"], move |args| {
+                let comps = comps_ref.borrow();
+                let window = comps.window.as_ref().unwrap();
+                let file_path = &args[0];
+                let dir = Path::new(&args[1]);
+                let filename = if file_path.is_empty() {
+                    "[No Name]"
+                } else if let Some(rel_path) = Path::new(&file_path)
+                    .strip_prefix(&dir)
+                    .ok()
+                    .and_then(|p| p.to_str())
+                {
+                    rel_path
+                } else {
+                    &file_path
+                };
+                window.set_title(filename);
+            });
 
         let comps_ref = self.comps.clone();
         let shell_ref = self.shell.clone();
@@ -222,12 +222,66 @@ impl Ui {
         let state_ref = self.shell.borrow().state.clone();
         let plug_manager_ref = self.plug_manager.clone();
         shell.set_nvim_started_cb(Some(move || {
+            let state = state_ref.borrow();
             plug_manager_ref
                 .borrow_mut()
                 .init_nvim_client(state_ref.borrow().nvim_clone());
+            state.set_autocmds();
+            state.run_now(&update_title);
+            if let Some(ref update_subtitle) = update_subtitle {
+                state.run_now(&update_subtitle);
+            }
         }));
     }
 
+    fn create_header_bar(&self) -> SubscriptionHandle {
+        let header_bar = HeaderBar::new();
+        let comps = self.comps.borrow();
+        let window = comps.window.as_ref().unwrap();
+
+        let projects = self.projects.clone();
+        header_bar.pack_start(&comps.open_btn);
+        comps
+            .open_btn
+            .connect_clicked(move |_| projects.borrow_mut().show());
+
+        let new_tab_btn = Button::new_from_icon_name(
+            "tab-new-symbolic",
+            gtk::IconSize::SmallToolbar.into(),
+        );
+        let shell_ref = Rc::clone(&self.shell);
+        new_tab_btn.connect_clicked(move |_| shell_ref.borrow_mut().new_tab());
+        new_tab_btn.set_can_focus(false);
+        header_bar.pack_start(&new_tab_btn);
+
+        let paste_btn = Button::new_from_icon_name(
+            "edit-paste",
+            gtk::IconSize::SmallToolbar.into(),
+        );
+        let shell = self.shell.clone();
+        paste_btn.connect_clicked(move |_| shell.borrow_mut().edit_paste());
+        paste_btn.set_can_focus(false);
+        header_bar.pack_end(&paste_btn);
+
+        let save_btn = Button::new_with_label("Save All");
+        let shell = self.shell.clone();
+        save_btn.connect_clicked(move |_| shell.borrow_mut().edit_save_all());
+        save_btn.set_can_focus(false);
+        header_bar.pack_end(&save_btn);
+
+        header_bar.set_show_close_button(true);
+
+        window.set_titlebar(Some(&header_bar));
+
+        let shell = self.shell.borrow();
+        let update_subtitle = shell.state.borrow()
+            .subscribe("DirChanged", &["getcwd()"], move |args| {
+                header_bar.set_subtitle(&*args[0]);
+            });
+
+        update_subtitle
+    }
+
     fn create_main_menu(&self, app: &gtk::Application, window: &gtk::ApplicationWindow) {
         let plug_manager = self.plug_manager.clone();