tui client wip

client_tui/src/app.rs

@@ -0,0 +1,53 @@
+// Application.
+#[derive(Debug, Default)]
+pub struct App {
+    // should the application exit?
+    pub should_quit: bool,
+    // counter
+    pub counter: u8,
+}
+
+impl App {
+    // Constructs a new instance of [`App`].
+    pub fn new() -> Self {
+        Self::default()
+    }
+
+    // Handles the tick event of the terminal.
+    pub fn tick(&self) {}
+
+    // Set running to false to quit the application.
+    pub fn quit(&mut self) {
+        self.should_quit = true;
+    }
+
+    pub fn increment_counter(&mut self) {
+        if let Some(res) = self.counter.checked_add(1) {
+            self.counter = res;
+        }
+    }
+
+    pub fn decrement_counter(&mut self) {
+        if let Some(res) = self.counter.checked_sub(1) {
+            self.counter = res;
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    #[test]
+    fn test_app_increment_counter() {
+        let mut app = App::default();
+        app.increment_counter();
+        assert_eq!(app.counter, 1);
+    }
+
+    #[test]
+    fn test_app_decrement_counter() {
+        let mut app = App::default();
+        app.decrement_counter();
+        assert_eq!(app.counter, 0);
+    }
+}

client_tui/src/event.rs

@@ -0,0 +1,87 @@
+use std::{
+    sync::mpsc,
+    thread,
+    time::{Duration, Instant},
+};
+
+use anyhow::Result;
+use crossterm::event::{self, Event as CrosstermEvent, KeyEvent, MouseEvent};
+
+// Terminal events.
+#[derive(Clone, Copy, Debug)]
+pub enum Event {
+    // Terminal tick.
+    Tick,
+    // Key press.
+    Key(KeyEvent),
+    // Mouse click/scroll.
+    Mouse(MouseEvent),
+    // Terminal resize.
+    Resize(u16, u16),
+}
+
+// Terminal event handler.
+#[derive(Debug)]
+pub struct EventHandler {
+    // Event sender channel.
+    #[allow(dead_code)]
+    sender: mpsc::Sender<Event>,
+    // Event receiver channel.
+    receiver: mpsc::Receiver<Event>,
+    // Event handler thread.
+    #[allow(dead_code)]
+    handler: thread::JoinHandle<()>,
+}
+
+impl EventHandler {
+    // Constructs a new instance of [`EventHandler`].
+    pub fn new(tick_rate: u64) -> Self {
+        let tick_rate = Duration::from_millis(tick_rate);
+        let (sender, receiver) = mpsc::channel();
+        let handler = {
+            let sender = sender.clone();
+            thread::spawn(move || {
+                let mut last_tick = Instant::now();
+                loop {
+                    let timeout = tick_rate
+                        .checked_sub(last_tick.elapsed())
+                        .unwrap_or(tick_rate);
+
+                    if event::poll(timeout).expect("no events available") {
+                        match event::read().expect("unable to read event") {
+                            CrosstermEvent::Key(e) => {
+                                if e.kind == event::KeyEventKind::Press {
+                                    sender.send(Event::Key(e))
+                                } else {
+                                    Ok(()) // ignore KeyEventKind::Release on windows
+                                }
+                            }
+                            CrosstermEvent::Mouse(e) => sender.send(Event::Mouse(e)),
+                            CrosstermEvent::Resize(w, h) => sender.send(Event::Resize(w, h)),
+                            _ => unimplemented!(),
+                        }
+                        .expect("failed to send terminal event")
+                    }
+
+                    if last_tick.elapsed() >= tick_rate {
+                        sender.send(Event::Tick).expect("failed to send tick event");
+                        last_tick = Instant::now();
+                    }
+                }
+            })
+        };
+        Self {
+            sender,
+            receiver,
+            handler,
+        }
+    }
+
+    // Receive the next event from the handler thread.
+    //
+    // This function will always block the current thread if
+    // there is no data available and it's possible for more data to be sent.
+    pub fn next(&self) -> Result<Event> {
+        Ok(self.receiver.recv()?)
+    }
+}

client_tui/src/main.rs

@@ -1,41 +1,50 @@
-use crossterm::{
-    event::{self, KeyCode, KeyEventKind},
-    terminal::{disable_raw_mode, enable_raw_mode, EnterAlternateScreen, LeaveAlternateScreen},
-    ExecutableCommand,
-};
-use ratatui::{
-    prelude::{CrosstermBackend, Stylize, Terminal},
-    widgets::Paragraph,
-};
-use std::io::{stdout, Result};
+// Application.
+pub mod app;
+
+// Terminal events handler.
+pub mod event;
+
+// Widget renderer.
+pub mod ui;
+
+// Terminal user interface.
+pub mod tui;
+
+// Application updater.
+pub mod update;
+
+use anyhow::Result;
+use app::App;
+use event::{Event, EventHandler};
+use ratatui::{backend::CrosstermBackend, Terminal};
+use tui::Tui;
+use update::update;
 
 fn main() -> Result<()> {
-    stdout().execute(EnterAlternateScreen)?;
-    enable_raw_mode()?;
-    let mut terminal = Terminal::new(CrosstermBackend::new(stdout()))?;
-    terminal.clear()?;
+    // Create an application.
+    let mut app = App::new();
 
-    loop {
-        terminal.draw(|frame| {
-            let area = frame.size();
-            frame.render_widget(
-                Paragraph::new("Hello Ratatui! (press 'q' to quit)")
-                .white()
-                .on_blue(),
-                area,
-                );
-        })?;
+    // Initialize the terminal user interface.
+    let backend = CrosstermBackend::new(std::io::stderr());
+    let terminal = Terminal::new(backend)?;
+    let events = EventHandler::new(250);
+    let mut tui = Tui::new(terminal, events);
+    tui.enter()?;
 
-        if event::poll(std::time::Duration::from_millis(16))? {
-            if let event::Event::Key(key) = event::read()? {
-                if key.kind == KeyEventKind::Press && key.code == KeyCode::Char('q') {
-                    break;
-                }
-            }
-        }
+    // Start the main loop.
+    while !app.should_quit {
+        // Render the user interface.
+        tui.draw(&mut app)?;
+        // Handle events.
+        match tui.events.next()? {
+            Event::Tick => {}
+            Event::Key(key_event) => update(&mut app, key_event),
+            Event::Mouse(_) => {}
+            Event::Resize(_, _) => {}
+        };
     }
 
-    stdout().execute(LeaveAlternateScreen)?;
-    disable_raw_mode()?;
+    // Exit the user interface.
+    tui.exit()?;
     Ok(())
 }

client_tui/src/tui.rs

@@ -0,0 +1,77 @@
+use std::{io, panic};
+
+use anyhow::Result;
+use crossterm::{
+    event::{DisableMouseCapture, EnableMouseCapture},
+    terminal::{self, EnterAlternateScreen, LeaveAlternateScreen},
+};
+
+pub type CrosstermTerminal = ratatui::Terminal<ratatui::backend::CrosstermBackend<std::io::Stderr>>;
+
+use crate::{app::App, event::EventHandler, ui};
+
+// Representation of a terminal user interface.
+//
+// It is responsible for setting up the terminal,
+// initializing the interface and handling the draw events.
+pub struct Tui {
+    // Interface to the Terminal.
+    terminal: CrosstermTerminal,
+    // Terminal event handler.
+    pub events: EventHandler,
+}
+
+impl Tui {
+    // Constructs a new instance of [`Tui`].
+    pub fn new(terminal: CrosstermTerminal, events: EventHandler) -> Self {
+        Self { terminal, events }
+    }
+
+    // Initializes the terminal interface.
+    //
+    // It enables the raw mode and sets terminal properties.
+    pub fn enter(&mut self) -> Result<()> {
+        terminal::enable_raw_mode()?;
+        crossterm::execute!(io::stderr(), EnterAlternateScreen, EnableMouseCapture)?;
+
+        // Define a custom panic hook to reset the terminal properties.
+        // This way, you won't have your terminal messed up if an unexpected error happens.
+        let panic_hook = panic::take_hook();
+        panic::set_hook(Box::new(move |panic| {
+            Self::reset().expect("failed to reset the terminal");
+            panic_hook(panic);
+        }));
+
+        self.terminal.hide_cursor()?;
+        self.terminal.clear()?;
+        Ok(())
+    }
+
+    // [`Draw`] the terminal interface by [`rendering`] the widgets.
+    //
+    // [`Draw`]: tui::Terminal::draw
+    // [`rendering`]: crate::ui:render
+    pub fn draw(&mut self, app: &mut App) -> Result<()> {
+        self.terminal.draw(|frame| ui::render(app, frame))?;
+        Ok(())
+    }
+
+    // Resets the terminal interface.
+    //
+    // This function is also used for the panic hook to revert
+    // the terminal properties if unexpected errors occur.
+    fn reset() -> Result<()> {
+        terminal::disable_raw_mode()?;
+        crossterm::execute!(io::stderr(), LeaveAlternateScreen, DisableMouseCapture)?;
+        Ok(())
+    }
+
+    // Exits the terminal interface.
+    //
+    // It disables the raw mode and reverts back the terminal properties.
+    pub fn exit(&mut self) -> Result<()> {
+        Self::reset()?;
+        self.terminal.show_cursor()?;
+        Ok(())
+    }
+}

client_tui/src/ui.rs

@@ -0,0 +1,30 @@
+use ratatui::{
+    prelude::{Alignment, Frame},
+    style::{Color, Style},
+    widgets::{Block, BorderType, Borders, Paragraph},
+};
+
+use crate::app::App;
+
+pub fn render(app: &mut App, f: &mut Frame) {
+    f.render_widget(
+        Paragraph::new(format!(
+            "
+        Press `Esc`, `Ctrl-C` or `q` to stop running.\n\
+        Press `j` and `k` to increment and decrement the counter respectively.\n\
+        Counter: {}
+      ",
+            app.counter
+        ))
+        .block(
+            Block::default()
+                .title("Counter App")
+                .title_alignment(Alignment::Center)
+                .borders(Borders::ALL)
+                .border_type(BorderType::Rounded),
+        )
+        .style(Style::default().fg(Color::Yellow))
+        .alignment(Alignment::Center),
+        f.size(),
+    )
+}

client_tui/src/update.rs

@@ -0,0 +1,17 @@
+use crossterm::event::{KeyCode, KeyEvent, KeyModifiers};
+
+use crate::app::App;
+
+pub fn update(app: &mut App, key_event: KeyEvent) {
+    match key_event.code {
+        KeyCode::Esc | KeyCode::Char('q') => app.quit(),
+        KeyCode::Char('c') | KeyCode::Char('C') => {
+            if key_event.modifiers == KeyModifiers::CONTROL {
+                app.quit()
+            }
+        }
+        KeyCode::Right | KeyCode::Char('j') => app.increment_counter(),
+        KeyCode::Left | KeyCode::Char('k') => app.decrement_counter(),
+        _ => {}
+    };
+}