Create App struct for TUI.

src/tui/app.rs

@@ -0,0 +1,146 @@
+use anyhow::Context;
+use ratatui::buffer::Buffer;
+use ratatui::crossterm::event;
+use ratatui::crossterm::event::{Event, KeyCode};
+use ratatui::layout::{Constraint, Direction, Layout, Rect};
+use ratatui::prelude::{Color, Style, Widget};
+use ratatui::widgets::{Block, Borders, Padding, Paragraph, Tabs, Wrap};
+use ratatui::{DefaultTerminal, symbols};
+use std::time::Duration;
+
+#[derive(Debug, Clone, Copy)]
+pub struct App<'a> {
+    root_path: &'a std::path::Path,
+}
+
+impl<'a> App<'a> {
+    pub(crate) fn new(root_path: &'a std::path::Path) -> Self {
+        Self { root_path }
+    }
+
+    pub fn run(mut self, mut terminal: DefaultTerminal) -> anyhow::Result<()> {
+        loop {
+            terminal.draw(|f| f.render_widget(self, f.area()))?;
+            if self.should_quit()? {
+                break;
+            }
+            self.handle_events()?;
+        }
+        Ok(())
+    }
+
+    fn handle_events(&mut self) -> anyhow::Result<()> {
+        // Handle other keyboard events here, aside from quitting.
+        Ok(())
+    }
+
+    fn should_quit(self) -> anyhow::Result<bool> {
+        if event::poll(Duration::from_millis(250)).context("event poll failed")? {
+            if let Event::Key(key) = event::read().context("event read failed")? {
+                return Ok(KeyCode::Char('q') == key.code);
+            }
+        }
+        Ok(false)
+    }
+
+    fn draw_status(self, area: Rect, buf: &mut Buffer) {
+        Tabs::new(["File", "Edit", "View", "Help"])
+            .style(Style::default())
+            .block(Block::default().borders(Borders::ALL))
+            .render(area, buf);
+    }
+
+    fn draw_tabs(self, area: Rect, buf: &mut Buffer) {
+        // TODO: Tabs should be opened from file explorer
+        Tabs::new(["file.md", "file.cpp"])
+            .divider(symbols::DOT)
+            .block(
+                Block::default()
+                    .borders(Borders::NONE)
+                    .padding(Padding::new(0, 0, 0, 0)),
+            )
+            .highlight_style(Style::default().fg(Color::LightRed))
+            .render(area, buf);
+    }
+
+    fn draw_editor(self, area: Rect, buf: &mut Buffer) {
+        // TODO: Title should be detected programming language name
+        // TODO: Content should be file contents
+        // TODO: Contents should use vim in rendered TTY
+        // TODO: Vimrc should be used
+        Paragraph::new("This is an example of the TUI interface (press 'q' to quit)")
+            .style(Style::default())
+            .block(
+                Block::default()
+                    .title("Rust")
+                    .title_style(Style::default().fg(Color::Yellow))
+                    .borders(Borders::ALL)
+                    .padding(Padding::new(0, 0, 0, 1)),
+            )
+            .wrap(Wrap { trim: false })
+            .render(area, buf);
+    }
+
+    fn draw_terminal(self, area: Rect, buf: &mut Buffer) {
+        // TODO: Title should be detected shell name
+        // TODO: Contents should be shell output
+        Paragraph::new("Terminal placeholder")
+            .style(Style::default())
+            .block(
+                Block::default()
+                    .title("Bash")
+                    .title_style(Style::default().fg(Color::DarkGray))
+                    .borders(Borders::ALL),
+            )
+            .wrap(Wrap { trim: false })
+            .render(area, buf);
+    }
+
+    fn draw_file_explorer(self, area: Rect, buf: &mut Buffer) {
+        Paragraph::new("File explorer placeholder")
+            .style(Style::default())
+            .block(Block::default().borders(Borders::ALL))
+            .render(area, buf);
+    }
+}
+
+// TODO: Separate complex components into their own widgets.
+impl<'a> Widget for App<'a> {
+    fn render(self, area: Rect, buf: &mut Buffer)
+    where
+        Self: Sized,
+    {
+        let vertical = Layout::default()
+            .direction(Direction::Vertical)
+            .constraints([
+                Constraint::Length(3),      // status bar
+                Constraint::Percentage(70), // horizontal layout
+                Constraint::Percentage(30), // terminal
+            ])
+            .split(area);
+
+        let horizontal = Layout::default()
+            .direction(Direction::Horizontal)
+            .constraints([
+                Constraint::Max(30), // File explorer with a max width of 30 characters.
+                Constraint::Fill(1), // Editor fills the remaining space.
+            ])
+            .split(vertical[1]);
+
+        let editor_layout = Layout::default()
+            .direction(Direction::Vertical)
+            .constraints([
+                Constraint::Length(1), // Editor tabs.
+                Constraint::Fill(1),
+            ])
+            .split(horizontal[1]);
+
+        self.draw_status(vertical[0], buf);
+        self.draw_terminal(vertical[2], buf);
+
+        self.draw_file_explorer(horizontal[0], buf);
+
+        self.draw_tabs(editor_layout[0], buf);
+        self.draw_editor(editor_layout[1], buf);
+    }
+}