1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
|
use crate::{
buffer::Buffer,
layout::Alignment,
text::{StyledGrapheme, Text},
widgets::{
reflow::{LineComposer, LineTruncator, WordWrapper},
Block, Widget,
},
};
use helix_core::unicode::width::UnicodeWidthStr;
use helix_view::graphics::{Rect, Style};
use std::iter;
fn get_line_offset(line_width: u16, text_area_width: u16, alignment: Alignment) -> u16 {
match alignment {
Alignment::Center => (text_area_width / 2).saturating_sub(line_width / 2),
Alignment::Right => text_area_width.saturating_sub(line_width),
Alignment::Left => 0,
}
}
/// A widget to display some text.
///
/// # Examples
///
/// ```
/// # use helix_tui::text::{Text, Spans, Span};
/// # use helix_tui::widgets::{Block, Borders, Paragraph, Wrap};
/// # use helix_tui::layout::{Alignment};
/// # use helix_view::graphics::{Style, Color, Modifier};
/// let text = vec![
/// Spans::from(vec![
/// Span::raw("First"),
/// Span::styled("line",Style::default().add_modifier(Modifier::ITALIC)),
/// Span::raw("."),
/// ]),
/// Spans::from(Span::styled("Second line", Style::default().fg(Color::Red))),
/// ];
/// Paragraph::new(text)
/// .block(Block::default().title("Paragraph").borders(Borders::ALL))
/// .style(Style::default().fg(Color::White).bg(Color::Black))
/// .alignment(Alignment::Center)
/// .wrap(Wrap { trim: true });
/// ```
#[derive(Debug, Clone)]
pub struct Paragraph<'a> {
/// A block to wrap the widget in
block: Option<Block<'a>>,
/// Widget style
style: Style,
/// How to wrap the text
wrap: Option<Wrap>,
/// The text to display
text: Text<'a>,
/// Scroll
scroll: (u16, u16),
/// Alignment of the text
alignment: Alignment,
}
/// Describes how to wrap text across lines.
///
/// ## Examples
///
/// ```
/// # use helix_tui::widgets::{Paragraph, Wrap};
/// # use helix_tui::text::Text;
/// let bullet_points = Text::from(r#"Some indented points:
/// - First thing goes here and is long so that it wraps
/// - Here is another point that is long enough to wrap"#);
///
/// // With leading spaces trimmed (window width of 30 chars):
/// Paragraph::new(bullet_points.clone()).wrap(Wrap { trim: true });
/// // Some indented points:
/// // - First thing goes here and is
/// // long so that it wraps
/// // - Here is another point that
/// // is long enough to wrap
///
/// // But without trimming, indentation is preserved:
/// Paragraph::new(bullet_points).wrap(Wrap { trim: false });
/// // Some indented points:
/// // - First thing goes here
/// // and is long so that it wraps
/// // - Here is another point
/// // that is long enough to wrap
/// ```
#[derive(Debug, Clone, Copy)]
pub struct Wrap {
/// Should leading whitespace be trimmed
pub trim: bool,
}
impl<'a> Paragraph<'a> {
pub fn new<T>(text: T) -> Paragraph<'a>
where
T: Into<Text<'a>>,
{
Paragraph {
block: None,
style: Default::default(),
wrap: None,
text: text.into(),
scroll: (0, 0),
alignment: Alignment::Left,
}
}
pub fn block(mut self, block: Block<'a>) -> Paragraph<'a> {
self.block = Some(block);
self
}
pub fn style(mut self, style: Style) -> Paragraph<'a> {
self.style = style;
self
}
pub fn wrap(mut self, wrap: Wrap) -> Paragraph<'a> {
self.wrap = Some(wrap);
self
}
pub fn scroll(mut self, offset: (u16, u16)) -> Paragraph<'a> {
self.scroll = offset;
self
}
pub fn alignment(mut self, alignment: Alignment) -> Paragraph<'a> {
self.alignment = alignment;
self
}
}
impl<'a> Widget for Paragraph<'a> {
fn render(mut self, area: Rect, buf: &mut Buffer) {
buf.set_style(area, self.style);
let text_area = match self.block.take() {
Some(b) => {
let inner_area = b.inner(area);
b.render(area, buf);
inner_area
}
None => area,
};
if text_area.height < 1 {
return;
}
let style = self.style;
let mut styled = self.text.lines.iter().flat_map(|spans| {
spans
.0
.iter()
.flat_map(|span| span.styled_graphemes(style))
// Required given the way composers work but might be refactored out if we change
// composers to operate on lines instead of a stream of graphemes.
.chain(iter::once(StyledGrapheme {
symbol: "\n",
style: self.style,
}))
});
let mut line_composer: Box<dyn LineComposer> = if let Some(Wrap { trim }) = self.wrap {
Box::new(WordWrapper::new(&mut styled, text_area.width, trim))
} else {
let mut line_composer = Box::new(LineTruncator::new(&mut styled, text_area.width));
if let Alignment::Left = self.alignment {
line_composer.set_horizontal_offset(self.scroll.1);
}
line_composer
};
let mut y = 0;
while let Some((current_line, current_line_width)) = line_composer.next_line() {
if y >= self.scroll.0 {
let mut x = get_line_offset(current_line_width, text_area.width, self.alignment);
for StyledGrapheme { symbol, style } in current_line {
buf[(text_area.left() + x, text_area.top() + y - self.scroll.0)]
.set_symbol(if symbol.is_empty() {
// If the symbol is empty, the last char which rendered last time will
// leave on the line. It's a quick fix.
" "
} else {
symbol
})
.set_style(*style);
x += symbol.width() as u16;
}
}
y += 1;
if y >= text_area.height + self.scroll.0 {
break;
}
}
}
}
|
