[tui] Set tab title to file name.

Also update to use anyhow::Result in some places.

src/gui.rs

@@ -1,10 +1,10 @@
+use anyhow::Result;
 use cxx_qt_lib::QString;
-use std::error::Error;
 
 pub mod colors;
 pub mod filesystem;
 
-pub fn run(root_path: std::path::PathBuf) -> Result<(), Box<dyn Error>> {
+pub fn run(root_path: std::path::PathBuf) -> Result<()> {
     println!("Starting the GUI editor at {:?}", root_path);
 
     use cxx_qt_lib::{QGuiApplication, QQmlApplicationEngine, QUrl};

src/main.rs

@@ -1,6 +1,4 @@
-// TODO: Header
+use anyhow::Result;
-
-use std::error::Error;
 use std::process::{Command, Stdio};
 use structopt::StructOpt;
 
@@ -25,7 +23,7 @@ struct Cli {
     pub gui: bool,
 }
 
-fn main() -> Result<(), Box<dyn Error>> {
+fn main() -> Result<()> {
     let args = Cli::from_args();
 
     let root_path = match args.path {

src/tui/app.rs

@@ -65,8 +65,16 @@ impl<'a> App<'a> {
     }
 
     fn draw_tabs(&self, area: Rect, buf: &mut Buffer) {
-        // TODO: Tabs should be opened from file explorer
+        // Determine the tab title from the current file (or use a fallback).
-        Tabs::new(["file.md", "file.cpp"])
+        let title = self
+            .editor
+            .file_path
+            .as_ref()
+            .and_then(|p| p.file_name())
+            .and_then(|s| s.to_str())
+            .unwrap_or("Untitled");
+
+        Tabs::new(vec![title])
             .divider(symbols::DOT)
             .block(
                 Block::default()