ratatui/examples/layout.rs
Josh McKinney fb93db0730
docs(examples): simplify docs using new layout methods (#731)
Use the new `Layout::horizontal` and `vertical` constructors and
`Rect::split_array` through all the examples.
2024-01-05 07:45:14 -08:00

208 lines
5.9 KiB
Rust

use std::{error::Error, io};
use crossterm::{
event::{self, DisableMouseCapture, EnableMouseCapture, Event, KeyCode},
execute,
terminal::{disable_raw_mode, enable_raw_mode, EnterAlternateScreen, LeaveAlternateScreen},
};
use itertools::Itertools;
use ratatui::{layout::Constraint::*, prelude::*, widgets::*};
fn main() -> Result<(), Box<dyn Error>> {
// setup terminal
enable_raw_mode()?;
let mut stdout = io::stdout();
execute!(stdout, EnterAlternateScreen, EnableMouseCapture)?;
let backend = CrosstermBackend::new(stdout);
let mut terminal = Terminal::new(backend)?;
// create app and run it
let res = run_app(&mut terminal);
// restore terminal
disable_raw_mode()?;
execute!(
terminal.backend_mut(),
LeaveAlternateScreen,
DisableMouseCapture
)?;
terminal.show_cursor()?;
if let Err(err) = res {
println!("{err:?}");
}
Ok(())
}
fn run_app<B: Backend>(terminal: &mut Terminal<B>) -> io::Result<()> {
loop {
terminal.draw(ui)?;
if let Event::Key(key) = event::read()? {
if let KeyCode::Char('q') = key.code {
return Ok(());
}
}
}
}
fn ui(frame: &mut Frame) {
let vertical = Layout::vertical([
Length(4), // text
Length(50), // examples
Min(0), // fills remaining space
]);
let [text_area, examples_area, _] = frame.size().split(&vertical);
// title
frame.render_widget(
Paragraph::new(vec![
Line::from("Horizontal Layout Example. Press q to quit".dark_gray())
.alignment(Alignment::Center),
Line::from("Each line has 2 constraints, plus Min(0) to fill the remaining space."),
Line::from("E.g. the second line of the Len/Min box is [Length(2), Min(2), Min(0)]"),
Line::from("Note: constraint labels that don't fit are truncated"),
]),
text_area,
);
let example_rows = Layout::vertical([
Length(9),
Length(9),
Length(9),
Length(9),
Length(9),
Min(0), // fills remaining space
])
.split(examples_area);
let example_areas = example_rows
.iter()
.flat_map(|area| {
Layout::horizontal([
Constraint::Length(14),
Constraint::Length(14),
Constraint::Length(14),
Constraint::Length(14),
Constraint::Length(14),
Constraint::Min(0), // fills remaining space
])
.split(*area)
.iter()
.copied()
.take(5) // ignore Min(0)
.collect_vec()
})
.collect_vec();
// the examples are a cartesian product of the following constraints
// e.g. Len/Len, Len/Min, Len/Max, Len/Perc, Len/Ratio, Min/Len, Min/Min, ...
let examples = [
(
"Len",
vec![
Length(0),
Length(2),
Length(3),
Length(6),
Length(10),
Length(15),
],
),
(
"Min",
vec![Min(0), Min(2), Min(3), Min(6), Min(10), Min(15)],
),
(
"Max",
vec![Max(0), Max(2), Max(3), Max(6), Max(10), Max(15)],
),
(
"Perc",
vec![
Percentage(0),
Percentage(25),
Percentage(50),
Percentage(75),
Percentage(100),
Percentage(150),
],
),
(
"Ratio",
vec![
Ratio(0, 4),
Ratio(1, 4),
Ratio(2, 4),
Ratio(3, 4),
Ratio(4, 4),
Ratio(6, 4),
],
),
];
for (i, (a, b)) in examples
.iter()
.cartesian_product(examples.iter())
.enumerate()
{
let (name_a, examples_a) = a;
let (name_b, examples_b) = b;
let constraints = examples_a
.iter()
.copied()
.zip(examples_b.iter().copied())
.collect_vec();
render_example_combination(
frame,
example_areas[i],
&format!("{name_a}/{name_b}"),
constraints,
);
}
}
/// Renders a single example box
fn render_example_combination(
frame: &mut Frame,
area: Rect,
title: &str,
constraints: Vec<(Constraint, Constraint)>,
) {
let block = Block::default()
.title(title.gray())
.style(Style::reset())
.borders(Borders::ALL)
.border_style(Style::default().fg(Color::DarkGray));
let inner = block.inner(area);
frame.render_widget(block, area);
let layout = Layout::vertical(vec![Length(1); constraints.len() + 1]).split(inner);
for (i, (a, b)) in constraints.iter().enumerate() {
render_single_example(frame, layout[i], vec![*a, *b, Min(0)]);
}
// This is to make it easy to visually see the alignment of the examples
// with the constraints.
frame.render_widget(Paragraph::new("123456789012"), layout[6]);
}
/// Renders a single example line
fn render_single_example(frame: &mut Frame, area: Rect, constraints: Vec<Constraint>) {
let red = Paragraph::new(constraint_label(constraints[0])).on_red();
let blue = Paragraph::new(constraint_label(constraints[1])).on_blue();
let green = Paragraph::new("·".repeat(12)).on_green();
let horizontal = Layout::horizontal(constraints);
let [r, b, g] = area.split(&horizontal);
frame.render_widget(red, r);
frame.render_widget(blue, b);
frame.render_widget(green, g);
}
fn constraint_label(constraint: Constraint) -> String {
match constraint {
Length(n) => format!("{n}"),
Min(n) => format!("{n}"),
Max(n) => format!("{n}"),
Percentage(n) => format!("{n}"),
Ratio(a, b) => format!("{a}:{b}"),
}
}