1use crate::{
2 black, point, px, size, BorrowWindow, Bounds, Hsla, Pixels, Point, Result, Size,
3 UnderlineStyle, WindowContext, WrapBoundary, WrappedLineLayout,
4};
5use smallvec::SmallVec;
6use std::sync::Arc;
7
8#[derive(Debug, Clone)]
9pub struct DecorationRun {
10 pub len: u32,
11 pub color: Hsla,
12 pub underline: Option<UnderlineStyle>,
13}
14
15#[derive(Clone, Default, Debug)]
16pub struct Line {
17 pub(crate) layout: Arc<WrappedLineLayout>,
18 pub(crate) decorations: SmallVec<[DecorationRun; 32]>,
19}
20
21impl Line {
22 pub fn size(&self, line_height: Pixels) -> Size<Pixels> {
23 size(
24 self.layout.width,
25 line_height * (self.layout.wrap_boundaries.len() + 1),
26 )
27 }
28
29 pub fn wrap_count(&self) -> usize {
30 self.layout.wrap_boundaries.len()
31 }
32
33 pub fn paint(
34 &self,
35 origin: Point<Pixels>,
36 line_height: Pixels,
37 cx: &mut WindowContext,
38 ) -> Result<()> {
39 let padding_top =
40 (line_height - self.layout.layout.ascent - self.layout.layout.descent) / 2.;
41 let baseline_offset = point(px(0.), padding_top + self.layout.layout.ascent);
42
43 let mut style_runs = self.decorations.iter();
44 let mut wraps = self.layout.wrap_boundaries.iter().peekable();
45 let mut run_end = 0;
46 let mut color = black();
47 let mut current_underline: Option<(Point<Pixels>, UnderlineStyle)> = None;
48 let text_system = cx.text_system().clone();
49
50 let mut glyph_origin = origin;
51 let mut prev_glyph_position = Point::default();
52 for (run_ix, run) in self.layout.layout.runs.iter().enumerate() {
53 let max_glyph_size = text_system
54 .bounding_box(run.font_id, self.layout.layout.font_size)?
55 .size;
56
57 for (glyph_ix, glyph) in run.glyphs.iter().enumerate() {
58 glyph_origin.x += glyph.position.x - prev_glyph_position.x;
59
60 if wraps.peek() == Some(&&WrapBoundary { run_ix, glyph_ix }) {
61 wraps.next();
62 if let Some((underline_origin, underline_style)) = current_underline.take() {
63 cx.paint_underline(
64 underline_origin,
65 glyph_origin.x - underline_origin.x,
66 &underline_style,
67 )?;
68 }
69
70 glyph_origin.x = origin.x;
71 glyph_origin.y += line_height;
72 }
73 prev_glyph_position = glyph.position;
74 let glyph_origin = glyph_origin + baseline_offset;
75
76 let mut finished_underline: Option<(Point<Pixels>, UnderlineStyle)> = None;
77 if glyph.index >= run_end {
78 if let Some(style_run) = style_runs.next() {
79 if let Some((_, underline_style)) = &mut current_underline {
80 if style_run.underline.as_ref() != Some(underline_style) {
81 finished_underline = current_underline.take();
82 }
83 }
84 if let Some(run_underline) = style_run.underline.as_ref() {
85 current_underline.get_or_insert((
86 point(
87 glyph_origin.x,
88 origin.y
89 + baseline_offset.y
90 + (self.layout.layout.descent * 0.618),
91 ),
92 UnderlineStyle {
93 color: Some(run_underline.color.unwrap_or(style_run.color)),
94 thickness: run_underline.thickness,
95 wavy: run_underline.wavy,
96 },
97 ));
98 }
99
100 run_end += style_run.len as usize;
101 color = style_run.color;
102 } else {
103 run_end = self.layout.text.len();
104 finished_underline = current_underline.take();
105 }
106 }
107
108 if let Some((underline_origin, underline_style)) = finished_underline {
109 cx.paint_underline(
110 underline_origin,
111 glyph_origin.x - underline_origin.x,
112 &underline_style,
113 )?;
114 }
115
116 let max_glyph_bounds = Bounds {
117 origin: glyph_origin,
118 size: max_glyph_size,
119 };
120
121 let content_mask = cx.content_mask();
122 if max_glyph_bounds.intersects(&content_mask.bounds) {
123 if glyph.is_emoji {
124 cx.paint_emoji(
125 glyph_origin,
126 run.font_id,
127 glyph.id,
128 self.layout.layout.font_size,
129 )?;
130 } else {
131 cx.paint_glyph(
132 glyph_origin,
133 run.font_id,
134 glyph.id,
135 self.layout.layout.font_size,
136 color,
137 )?;
138 }
139 }
140 }
141 }
142
143 if let Some((underline_start, underline_style)) = current_underline.take() {
144 let line_end_x = origin.x + self.layout.layout.width;
145 cx.paint_underline(
146 underline_start,
147 line_end_x - underline_start.x,
148 &underline_style,
149 )?;
150 }
151
152 Ok(())
153 }
154}