Fixes #1 Temproray fix that allows open single file

To make good fix wait for gtk-rs bindings udpate for optons/open support
inside GtkApplication

src/main.rs

@@ -28,7 +28,10 @@ fn main() {
     app.connect_activate(activate);
 
     let args: Vec<String> = env::args().collect();
-    let argv: Vec<&str> = args.iter().filter(|a| !a.starts_with(BIN_PATH_ARG)).map(String::as_str).collect();
+    let mut argv: Vec<&str> = args.iter().filter(|a| !a.starts_with(BIN_PATH_ARG)).map(String::as_str).collect();
+    if open_arg().is_some() {
+        argv.pop();
+    }
     app.run(argv.len() as i32, &argv);
 }
 
@@ -37,21 +40,39 @@ fn activate(app: &gtk::Application) {
         let mut ui = ui_cell.borrow_mut();
         ui.init(app);
 
-        let path = nvim_bin_path();
+        let path = nvim_bin_path(std::env::args());
-        nvim::initialize(&mut *ui, path.as_ref()).expect("Can't start nvim instance");
+        let open_arg = open_arg();
+        nvim::initialize(&mut *ui, path.as_ref(), open_arg.as_ref()).expect("Can't start nvim instance");
 
         guard_dispatch_thread(&mut *ui);
     });
 }
 
-fn nvim_bin_path() -> Option<String> {
+fn nvim_bin_path<I>(args: I) -> Option<String> 
-    std::env::args()
+    where I: Iterator<Item=String>
-        .skip_while(|a| !a.starts_with(BIN_PATH_ARG))
+{
+    args.skip_while(|a| !a.starts_with(BIN_PATH_ARG))
         .map(|p| p.split('=').nth(1).map(str::to_owned))
         .nth(0)
         .unwrap_or(None)
 }
 
+fn open_arg() -> Option<String> {
+   open_arg_impl(std::env::args())
+}
+
+fn open_arg_impl<I>(args: I) -> Option<String> 
+    where I: Iterator<Item=String>
+{
+    args.last().map(|a| {
+        if !a.starts_with("-") {
+            Some(a.to_owned())
+        } else {
+            None
+        }
+    }).unwrap_or(None)
+}
+
 fn guard_dispatch_thread(ui: &mut ui::Ui) {
     let guard = ui.nvim().session.take_dispatch_guard();
     thread::spawn(move || {
@@ -64,3 +85,20 @@ fn guard_dispatch_thread(ui: &mut ui::Ui) {
         });
     });
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_bin_path_arg() {
+        assert_eq!(Some("/test_path".to_string()), 
+                   nvim_bin_path(vec!["neovim-gtk", "--nvim-bin-path=/test_path"].iter().map(|s| s.to_string())));
+    }
+
+    #[test]
+    fn test_open_arg() {
+        assert_eq!(Some("some_file.txt".to_string()), 
+                   open_arg_impl(vec!["neovim-gtk", "--nvim-bin-path=/test_path", "some_file.txt"].iter().map(|s| s.to_string())));
+    }
+}

src/nvim.rs

@@ -64,7 +64,7 @@ macro_rules! try_uint {
     })
 }
 
-pub fn initialize(ui: &mut Ui, nvim_bin_path: Option<&String>) -> Result<()> {
+pub fn initialize(ui: &mut Ui, nvim_bin_path: Option<&String>, open_arg: Option<&String>) -> Result<()> {
     let session = if let Some(path) = nvim_bin_path {
         Session::new_child_path(path)?
     } else {
@@ -81,6 +81,10 @@ pub fn initialize(ui: &mut Ui, nvim_bin_path: Option<&String>) -> Result<()> {
     nvim.ui_attach(80, 24, UiAttachOptions::new()).map_err(|e| Error::new(ErrorKind::Other, e))?;
     nvim.command("runtime! ginit.vim").map_err(|e| Error::new(ErrorKind::Other, e))?;
 
+    if let Some(ref file) = open_arg {
+        nvim.command(&format!("e {}", file)).report_err(nvim);
+    }
+
     Ok(())
 }