feat: minimal app setup

Cargo.toml

@@ -1,5 +1,8 @@
 [package]
 name = "tlock"
-version = "0.0.1"
+version = "0.1.0"
 edition = "2021"
 
+[dependencies]
+crossterm = "0.27.0"
+

src/main.rs

@@ -1,5 +1,77 @@
-use std::time::SystemTime;
+use std::{
+    io::{self, Write},
+    thread,
+    time::Duration,
+};
 
-fn main() {
-    println!("{:?}", SystemTime::now());
+use crossterm::{
+    cursor,
+    event::{self, Event, KeyCode, KeyModifiers},
+    execute, queue,
+    style::{self, Color},
+    terminal::{self, ClearType},
+};
+
+fn main() -> io::Result<()> {
+    let mut stdout = io::stdout();
+
+    // Switch to alternate screen, hide the cursor and enable raw mode
+    execute!(stdout, terminal::EnterAlternateScreen, cursor::Hide)?;
+    let _ = terminal::enable_raw_mode()?;
+
+    // Main loop
+    let mut quit = false;
+    while !quit {
+        // Handle events
+        while event::poll(Duration::ZERO)? {
+            match event::read()? {
+                Event::Key(e) => match e.code {
+                    KeyCode::Char(x) => {
+                        // Handle CTRL-C
+                        if x == 'c' && e.modifiers.contains(KeyModifiers::CONTROL) {
+                            quit = true;
+                        }
+                    }
+                    _ => {}
+                },
+                _ => {}
+            }
+        }
+
+        // Clear frame
+        queue!(stdout, terminal::Clear(ClearType::All))?;
+
+        // Render
+        render_frame()?;
+
+        stdout.flush()?;
+
+        // 30fps
+        thread::sleep(Duration::from_millis(33));
+    }
+
+    // Disale raw mode, leave the alternate screen and show the cursor back
+    let _ = terminal::disable_raw_mode().unwrap();
+    execute!(stdout, terminal::LeaveAlternateScreen, cursor::Show)?;
+
+    // Be polite
+    println!("CTRL-C pressed, bye!\n");
+
+    return Ok(());
+}
+
+fn render_frame() -> io::Result<()> {
+    let mut stdout = io::stdout();
+    let (width, height) = terminal::size()?;
+
+    // Render red X at middle of screen
+    queue!(
+        stdout,
+        cursor::MoveTo(width / 2, height / 2),
+        style::SetForegroundColor(Color::Red)
+    )?;
+
+    write!(stdout, "X")?;
+
+    return Ok(());
 }