Improve event handling and the main loop

editor-challenge/src/main.rs

@@ -1,11 +1,23 @@
-use crossterm::{event::{self, KeyCode, KeyEvent}, terminal::{disable_raw_mode, enable_raw_mode}};
-use std::{io::{self, Read}, sync::mpsc, thread, time::{Duration, Instant}};
+use crossterm::{
+    event::{self, KeyCode, KeyEvent, KeyModifiers},
+    terminal::{disable_raw_mode, enable_raw_mode},
+};
+use std::{
+    io::{self, Read},
+    sync::mpsc,
+    thread,
+    time::{Duration, Instant},
+};
 use tui::{
-    backend::CrosstermBackend, layout::{Alignment, Constraint, Direction, Layout}, style::{Color, Style}, widgets::{Block, BorderType, Borders, Paragraph}, Terminal
+    backend::CrosstermBackend,
+    layout::{Alignment, Constraint, Direction, Layout},
+    style::{Color, Style},
+    widgets::{Block, BorderType, Borders, Paragraph},
+    Terminal,
 };
 
-const TITLE: &str = "Editor Challenge";
-const COPYRIGHT: &str = "Editor Challenge, (c) Savanni D'Gerinel - all rights reserved";
+const TITLE: &str = "Text Editor Challenge";
+const COPYRIGHT: &str = "(c) Savanni D'Gerinel - all rights reserved";
 const TICK_RATE_MS: u64 = 200;
 
 fn render<T>(terminal: &mut Terminal<T>) -> Result<(), anyhow::Error>
@@ -54,6 +66,7 @@ where
     Ok(())
 }
 
+#[derive(Debug)]
 enum Event<I> {
     Input(I),
     Tick,
@@ -62,7 +75,8 @@ enum Event<I> {
 fn handle_input(tx: mpsc::Sender<Event<KeyEvent>>, tick_rate: Duration) {
     let mut last_tick = Instant::now();
     loop {
-            let timeout = tick_rate.checked_sub(last_tick.elapsed())
+        let timeout = tick_rate
+            .checked_sub(last_tick.elapsed())
             .unwrap_or_else(|| Duration::from_secs(0));
 
         if event::poll(timeout).expect("poll works") {
@@ -79,6 +93,30 @@ fn handle_input(tx: mpsc::Sender<Event<KeyEvent>>, tick_rate: Duration) {
     }
 }
 
+fn app_loop<T>(
+    terminal: &mut Terminal<T>,
+    rx: mpsc::Receiver<Event<KeyEvent>>,
+) -> Result<(), anyhow::Error>
+where
+    T: tui::backend::Backend,
+{
+    loop {
+        render(terminal)?;
+
+        let event = rx.recv()?;
+
+        match event {
+            Event::Input(KeyEvent { code, modifiers })
+                if code == KeyCode::Char('x') && modifiers == KeyModifiers::CONTROL =>
+            {
+                break;
+            }
+            _ => {}
+        }
+    }
+    Ok(())
+}
+
 fn main() -> Result<(), anyhow::Error> {
     let (tx, rx) = mpsc::channel();
 
@@ -94,17 +132,12 @@ fn main() -> Result<(), anyhow::Error> {
     let mut terminal = Terminal::new(backend)?;
     let _ = terminal.clear()?;
 
-    loop {
-        render(&mut terminal)?;
+    let result = app_loop(&mut terminal, rx);
 
-        let event = rx.recv()?;
-
-        match event {
-            Event::Input(KeyEvent{ code, .. }) if code == KeyCode::Char('q') => {
     disable_raw_mode()?;
-                return Ok(());
-            }
-            _ => {},
-        }
-    }
+    terminal.show_cursor()?;
+
+    result?;
+
+    Ok(())
 }