use ratatui::{
backend::TestBackend,
buffer::Buffer,
layout::Alignment,
text::{Line, Span, Text},
widgets::{Block, Borders, Padding, Paragraph, Wrap},
Terminal,
};
#[allow(clippy::needless_pass_by_value)]
fn test_case(paragraph: Paragraph, expected: Buffer) {
let backend = TestBackend::new(expected.area.width, expected.area.height);
let mut terminal = Terminal::new(backend).unwrap();
terminal
.draw(|f| {
let size = f.size();
f.render_widget(paragraph, size);
})
.unwrap();
terminal.backend().assert_buffer(&expected);
}
#[test]
fn widgets_paragraph_renders_double_width_graphemes() {
let s = "コンピュータ上で文字を扱う場合、典型的には文字による通信を行う場合にその両端点では、";
let text = vec![Line::from(s)];
let paragraph = Paragraph::new(text)
.block(Block::default().borders(Borders::ALL))
.wrap(Wrap { trim: true });
test_case(
paragraph,
Buffer::with_lines(vec![
"┌────────┐",
"│コンピュ│",
"│ータ上で│",
"│文字を扱│",
"│う場合、│",
"│典型的に│",
"│は文字に│",
"│よる通信│",
"│を行う場│",
"└────────┘",
]),
);
}
#[test]
fn widgets_paragraph_renders_mixed_width_graphemes() {
let backend = TestBackend::new(10, 7);
let mut terminal = Terminal::new(backend).unwrap();
let s = "aコンピュータ上で文字を扱う場合、";
terminal
.draw(|f| {
let size = f.size();
let text = vec![Line::from(s)];
let paragraph = Paragraph::new(text)
.block(Block::default().borders(Borders::ALL))
.wrap(Wrap { trim: true });
f.render_widget(paragraph, size);
})
.unwrap();
let expected = Buffer::with_lines(vec![
"┌────────┐",
"│aコンピ │", "│ュータ上│",
"│で文字を│",
"│扱う場合│",
"│、 │",
"└────────┘",
]);
terminal.backend().assert_buffer(&expected);
}
#[test]
fn widgets_paragraph_can_wrap_with_a_trailing_nbsp() {
let nbsp = "\u{00a0}";
let line = Line::from(vec![Span::raw("NBSP"), Span::raw(nbsp)]);
let paragraph = Paragraph::new(line).block(Block::default().borders(Borders::ALL));
test_case(
paragraph,
Buffer::with_lines(vec![
"┌──────────────────┐",
"│NBSP\u{00a0} │",
"└──────────────────┘",
]),
);
}
#[test]
fn widgets_paragraph_can_scroll_horizontally() {
let text =
Text::from("段落现在可以水平滚动了！\nParagraph can scroll horizontally!\nLittle line");
let paragraph = Paragraph::new(text).block(Block::default().borders(Borders::ALL));
test_case(
paragraph.clone().alignment(Alignment::Left).scroll((0, 7)),
Buffer::with_lines(vec![
"┌──────────────────┐",
"│在可以水平滚动了！│",
"│ph can scroll hori│",
"│line │",
"│ │",
"│ │",
"│ │",
"│ │",
"│ │",
"└──────────────────┘",
]),
);
test_case(
paragraph.clone().alignment(Alignment::Right).scroll((0, 7)),
Buffer::with_lines(vec![
"┌──────────────────┐",
"│段落现在可以水平滚│",
"│Paragraph can scro│",
"│ Little line│",
"│ │",
"│ │",
"│ │",
"│ │",
"│ │",
"└──────────────────┘",
]),
);
}
const SAMPLE_STRING: &str = "The library is based on the principle of immediate rendering with \
intermediate buffers. This means that at each new frame you should build all widgets that are \
supposed to be part of the UI. While providing a great flexibility for rich and \
interactive UI, this may introduce overhead for highly dynamic content.";
#[test]
fn widgets_paragraph_can_wrap_its_content() {
let text = vec![Line::from(SAMPLE_STRING)];
let paragraph = Paragraph::new(text)
.block(Block::default().borders(Borders::ALL))
.wrap(Wrap { trim: true });
test_case(
paragraph.clone().alignment(Alignment::Left),
Buffer::with_lines(vec![
"┌──────────────────┐",
"│The library is │",
"│based on the │",
"│principle of │",
"│immediate │",
"│rendering with │",
"│intermediate │",
"│buffers. This │",
"│means that at each│",
"└──────────────────┘",
]),
);
test_case(
paragraph.clone().alignment(Alignment::Center),
Buffer::with_lines(vec![
"┌──────────────────┐",
"│ The library is │",
"│ based on the │",
"│ principle of │",
"│ immediate │",
"│ rendering with │",
"│ intermediate │",
"│ buffers. This │",
"│means that at each│",
"└──────────────────┘",
]),
);
test_case(
paragraph.clone().alignment(Alignment::Right),
Buffer::with_lines(vec![
"┌──────────────────┐",
"│ The library is│",
"│ based on the│",
"│ principle of│",
"│ immediate│",
"│ rendering with│",
"│ intermediate│",
"│ buffers. This│",
"│means that at each│",
"└──────────────────┘",
]),
);
}
#[test]
fn widgets_paragraph_works_with_padding() {
let text = vec![Line::from(SAMPLE_STRING)];
let paragraph = Paragraph::new(text)
.block(Block::default().borders(Borders::ALL).padding(Padding {
left: 2,
right: 2,
top: 1,
bottom: 1,
}))
.wrap(Wrap { trim: true });
test_case(
paragraph.clone().alignment(Alignment::Left),
Buffer::with_lines(vec![
"┌────────────────────┐",
"│ │",
"│ The library is │",
"│ based on the │",
"│ principle of │",
"│ immediate │",
"│ rendering with │",
"│ intermediate │",
"│ buffers. This │",
"│ means that at │",
"│ │",
"└────────────────────┘",
]),
);
test_case(
paragraph.clone().alignment(Alignment::Right),
Buffer::with_lines(vec![
"┌────────────────────┐",
"│ │",
"│ The library is │",
"│ based on the │",
"│ principle of │",
"│ immediate │",
"│ rendering with │",
"│ intermediate │",
"│ buffers. This │",
"│ means that at │",
"│ │",
"└────────────────────┘",
]),
);
let mut text = vec![Line::from("This is always centered.").alignment(Alignment::Center)];
text.push(Line::from(SAMPLE_STRING));
let paragraph = Paragraph::new(text)
.block(Block::default().borders(Borders::ALL).padding(Padding {
left: 2,
right: 2,
top: 1,
bottom: 1,
}))
.wrap(Wrap { trim: true });
test_case(
paragraph.alignment(Alignment::Right),
Buffer::with_lines(vec![
"┌────────────────────┐",
"│ │",
"│ This is always │",
"│ centered. │",
"│ The library is │",
"│ based on the │",
"│ principle of │",
"│ immediate │",
"│ rendering with │",
"│ intermediate │",
"│ buffers. This │",
"│ means that at │",
"│ │",
"└────────────────────┘",
]),
);
}
#[test]
fn widgets_paragraph_can_align_spans() {
let right_s = "This string will override the paragraph alignment to be right aligned.";
let default_s = "This string will be aligned based on the alignment of the paragraph.";
let text = vec![
Line::from(right_s).alignment(Alignment::Right),
Line::from(default_s),
];
let paragraph = Paragraph::new(text)
.block(Block::default().borders(Borders::ALL))
.wrap(Wrap { trim: true });
test_case(
paragraph.clone().alignment(Alignment::Left),
Buffer::with_lines(vec![
"┌──────────────────┐",
"│ This string will│",
"│ override the│",
"│ paragraph│",
"│ alignment to be│",
"│ right aligned.│",
"│This string will │",
"│be aligned based │",
"│on the alignment │",
"└──────────────────┘",
]),
);
test_case(
paragraph.alignment(Alignment::Center),
Buffer::with_lines(vec![
"┌──────────────────┐",
"│ This string will│",
"│ override the│",
"│ paragraph│",
"│ alignment to be│",
"│ right aligned.│",
"│ This string will │",
"│ be aligned based │",
"│ on the alignment │",
"└──────────────────┘",
]),
);
let left_lines = vec!["This string", "will override the paragraph alignment"]
.into_iter()
.map(|s| Line::from(s).alignment(Alignment::Left))
.collect::<Vec<_>>();
let mut lines = vec![
"This",
"must be pretty long",
"in order to effectively show",
"truncation.",
]
.into_iter()
.map(Line::from)
.collect::<Vec<_>>();
let mut text = left_lines.clone();
text.append(&mut lines);
let paragraph = Paragraph::new(text).block(Block::default().borders(Borders::ALL));
test_case(
paragraph.clone().alignment(Alignment::Right),
Buffer::with_lines(vec![
"┌──────────────────┐",
"│This string │",
"│will override the │",
"│ This│",
"│must be pretty lon│",
"│in order to effect│",
"│ truncation.│",
"│ │",
"│ │",
"└──────────────────┘",
]),
);
test_case(
paragraph.alignment(Alignment::Left),
Buffer::with_lines(vec![
"┌──────────────────┐",
"│This string │",
"│will override the │",
"│This │",
"│must be pretty lon│",
"│in order to effect│",
"│truncation. │",
"│ │",
"└──────────────────┘",
]),
);
}