ratatui/examples/block.rs
Josh McKinney fbf1a451c8
chore: simplify constraints (#556)
Use bare arrays rather than array refs / Vecs for all constraint
examples.

Ref: https://github.com/ratatui-org/ratatui-book/issues/94
2023-10-03 16:50:14 -07:00

252 lines
8.5 KiB
Rust

use std::{
error::Error,
io::{stdout, Stdout},
ops::ControlFlow,
time::Duration,
};
use crossterm::{
event::{self, Event, KeyCode},
execute,
terminal::{disable_raw_mode, enable_raw_mode, EnterAlternateScreen, LeaveAlternateScreen},
};
use itertools::Itertools;
use ratatui::{
prelude::*,
widgets::{
block::{Position, Title},
Block, BorderType, Borders, Padding, Paragraph, Wrap,
},
};
// These type aliases are used to make the code more readable by reducing repetition of the generic
// types. They are not necessary for the functionality of the code.
type Terminal = ratatui::Terminal<CrosstermBackend<Stdout>>;
type Result<T> = std::result::Result<T, Box<dyn Error>>;
fn main() -> Result<()> {
let mut terminal = setup_terminal()?;
let result = run(&mut terminal);
restore_terminal(terminal)?;
if let Err(err) = result {
eprintln!("{err:?}");
}
Ok(())
}
fn setup_terminal() -> Result<Terminal> {
enable_raw_mode()?;
let mut stdout = stdout();
execute!(stdout, EnterAlternateScreen)?;
let backend = CrosstermBackend::new(stdout);
let terminal = Terminal::new(backend)?;
Ok(terminal)
}
fn restore_terminal(mut terminal: Terminal) -> Result<()> {
disable_raw_mode()?;
execute!(terminal.backend_mut(), LeaveAlternateScreen)?;
Ok(())
}
fn run(terminal: &mut Terminal) -> Result<()> {
loop {
terminal.draw(ui)?;
if handle_events()?.is_break() {
return Ok(());
}
}
}
fn handle_events() -> Result<ControlFlow<()>> {
if event::poll(Duration::from_millis(100))? {
if let Event::Key(key) = event::read()? {
if let KeyCode::Char('q') = key.code {
return Ok(ControlFlow::Break(()));
}
}
}
Ok(ControlFlow::Continue(()))
}
fn ui(frame: &mut Frame) {
let (title_area, layout) = calculate_layout(frame.size());
render_title(frame, title_area);
let paragraph = placeholder_paragraph();
render_borders(&paragraph, Borders::ALL, frame, layout[0][0]);
render_borders(&paragraph, Borders::NONE, frame, layout[0][1]);
render_borders(&paragraph, Borders::LEFT, frame, layout[1][0]);
render_borders(&paragraph, Borders::RIGHT, frame, layout[1][1]);
render_borders(&paragraph, Borders::TOP, frame, layout[2][0]);
render_borders(&paragraph, Borders::BOTTOM, frame, layout[2][1]);
render_border_type(&paragraph, BorderType::Plain, frame, layout[3][0]);
render_border_type(&paragraph, BorderType::Rounded, frame, layout[3][1]);
render_border_type(&paragraph, BorderType::Double, frame, layout[4][0]);
render_border_type(&paragraph, BorderType::Thick, frame, layout[4][1]);
render_styled_block(&paragraph, frame, layout[5][0]);
render_styled_borders(&paragraph, frame, layout[5][1]);
render_styled_title(&paragraph, frame, layout[6][0]);
render_styled_title_content(&paragraph, frame, layout[6][1]);
render_multiple_titles(&paragraph, frame, layout[7][0]);
render_multiple_title_positions(&paragraph, frame, layout[7][1]);
render_padding(&paragraph, frame, layout[8][0]);
render_nested_blocks(&paragraph, frame, layout[8][1]);
}
/// Calculate the layout of the UI elements.
///
/// Returns a tuple of the title area and the main areas.
fn calculate_layout(area: Rect) -> (Rect, Vec<Vec<Rect>>) {
let layout = Layout::default()
.direction(Direction::Vertical)
.constraints([Constraint::Length(1), Constraint::Min(0)])
.split(area);
let title_area = layout[0];
let main_areas = Layout::default()
.direction(Direction::Vertical)
.constraints([Constraint::Max(4); 9])
.split(layout[1])
.iter()
.map(|&area| {
Layout::default()
.direction(Direction::Horizontal)
.constraints([Constraint::Percentage(50), Constraint::Percentage(50)])
.split(area)
.to_vec()
})
.collect_vec();
(title_area, main_areas)
}
fn render_title(frame: &mut Frame, area: Rect) {
frame.render_widget(
Paragraph::new("Block example. Press q to quit")
.dark_gray()
.alignment(Alignment::Center),
area,
);
}
fn placeholder_paragraph() -> Paragraph<'static> {
let text = "Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.";
Paragraph::new(text.dark_gray()).wrap(Wrap { trim: true })
}
fn render_borders(paragraph: &Paragraph, border: Borders, frame: &mut Frame, area: Rect) {
let block = Block::new()
.borders(border)
.title(format!("Borders::{border:#?}", border = border));
frame.render_widget(paragraph.clone().block(block), area);
}
fn render_border_type(
paragraph: &Paragraph,
border_type: BorderType,
frame: &mut Frame,
area: Rect,
) {
let block = Block::new()
.borders(Borders::ALL)
.border_type(border_type)
.title(format!("BorderType::{border_type:#?}"));
frame.render_widget(paragraph.clone().block(block), area);
}
fn render_styled_borders(paragraph: &Paragraph, frame: &mut Frame, area: Rect) {
let block = Block::new()
.borders(Borders::ALL)
.border_style(Style::new().blue().on_white().bold().italic())
.title("Styled borders");
frame.render_widget(paragraph.clone().block(block), area);
}
fn render_styled_block(paragraph: &Paragraph, frame: &mut Frame, area: Rect) {
let block = Block::new()
.borders(Borders::ALL)
.style(Style::new().blue().on_white().bold().italic())
.title("Styled block");
frame.render_widget(paragraph.clone().block(block), area);
}
// Note: this currently renders incorrectly, see https://github.com/ratatui-org/ratatui/issues/349
fn render_styled_title(paragraph: &Paragraph, frame: &mut Frame, area: Rect) {
let block = Block::new()
.borders(Borders::ALL)
.title("Styled title")
.title_style(Style::new().blue().on_white().bold().italic());
frame.render_widget(paragraph.clone().block(block), area);
}
fn render_styled_title_content(paragraph: &Paragraph, frame: &mut Frame, area: Rect) {
let title = Line::from(vec![
"Styled ".blue().on_white().bold().italic(),
"title content".red().on_white().bold().italic(),
]);
let block = Block::new().borders(Borders::ALL).title(title);
frame.render_widget(paragraph.clone().block(block), area);
}
fn render_multiple_titles(paragraph: &Paragraph, frame: &mut Frame, area: Rect) {
let block = Block::new()
.borders(Borders::ALL)
.title("Multiple".blue().on_white().bold().italic())
.title("Titles".red().on_white().bold().italic());
frame.render_widget(paragraph.clone().block(block), area);
}
fn render_multiple_title_positions(paragraph: &Paragraph, frame: &mut Frame, area: Rect) {
let block = Block::new()
.borders(Borders::ALL)
.title(
Title::from("top left")
.position(Position::Top)
.alignment(Alignment::Left),
)
.title(
Title::from("top center")
.position(Position::Top)
.alignment(Alignment::Center),
)
.title(
Title::from("top right")
.position(Position::Top)
.alignment(Alignment::Right),
)
.title(
Title::from("bottom left")
.position(Position::Bottom)
.alignment(Alignment::Left),
)
.title(
Title::from("bottom center")
.position(Position::Bottom)
.alignment(Alignment::Center),
)
.title(
Title::from("bottom right")
.position(Position::Bottom)
.alignment(Alignment::Right),
);
frame.render_widget(paragraph.clone().block(block), area);
}
fn render_padding(paragraph: &Paragraph, frame: &mut Frame, area: Rect) {
let block = Block::new()
.borders(Borders::ALL)
.title("Padding")
.padding(Padding::new(5, 10, 1, 2));
frame.render_widget(paragraph.clone().block(block), area);
}
fn render_nested_blocks(paragraph: &Paragraph, frame: &mut Frame, area: Rect) {
let outer_block = Block::new().borders(Borders::ALL).title("Outer block");
let inner_block = Block::new().borders(Borders::ALL).title("Inner block");
let inner = outer_block.inner(area);
frame.render_widget(outer_block, area);
frame.render_widget(paragraph.clone().block(inner_block), inner);
}