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
|
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at https://mozilla.org/MPL/2.0/. */
//! Resolution values:
//!
//! https://drafts.csswg.org/css-values/#resolution
use crate::derives::*;
use crate::parser::{Parse, ParserContext};
use crate::values::specified::CalcNode;
use crate::values::CSSFloat;
use cssparser::{match_ignore_ascii_case, Parser, Token};
use std::fmt::{self, Write};
use style_traits::{CssWriter, ParseError, StyleParseErrorKind, ToCss};
/// A specified resolution.
#[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToShmem)]
pub struct Resolution {
value: CSSFloat,
unit: ResolutionUnit,
was_calc: bool,
}
#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToCss, ToShmem)]
enum ResolutionUnit {
/// Dots per inch.
Dpi,
/// An alias unit for dots per pixel.
X,
/// Dots per pixel.
Dppx,
/// Dots per centimeter.
Dpcm,
}
impl ResolutionUnit {
fn as_str(self) -> &'static str {
match self {
Self::Dpi => "dpi",
Self::X => "x",
Self::Dppx => "dppx",
Self::Dpcm => "dpcm",
}
}
}
impl Resolution {
/// Returns a resolution value from dppx units.
pub fn from_dppx(value: CSSFloat) -> Self {
Self {
value,
unit: ResolutionUnit::Dppx,
was_calc: false,
}
}
/// Returns a resolution value from dppx units.
pub fn from_x(value: CSSFloat) -> Self {
Self {
value,
unit: ResolutionUnit::X,
was_calc: false,
}
}
/// Returns a resolution value from dppx units.
pub fn from_dppx_calc(value: CSSFloat) -> Self {
Self {
value,
unit: ResolutionUnit::Dppx,
was_calc: true,
}
}
/// Convert this resolution value to dppx units.
pub fn dppx(&self) -> CSSFloat {
match self.unit {
ResolutionUnit::X | ResolutionUnit::Dppx => self.value,
_ => self.dpi() / 96.0,
}
}
/// Convert this resolution value to dpi units.
pub fn dpi(&self) -> CSSFloat {
match self.unit {
ResolutionUnit::Dpi => self.value,
ResolutionUnit::X | ResolutionUnit::Dppx => self.value * 96.0,
ResolutionUnit::Dpcm => self.value * 2.54,
}
}
/// Parse a resolution given a value and unit.
pub fn parse_dimension<'i, 't>(value: CSSFloat, unit: &str) -> Result<Self, ()> {
let unit = match_ignore_ascii_case! { &unit,
"dpi" => ResolutionUnit::Dpi,
"dppx" => ResolutionUnit::Dppx,
"dpcm" => ResolutionUnit::Dpcm,
"x" => ResolutionUnit::X,
_ => return Err(())
};
Ok(Self {
value,
unit,
was_calc: false,
})
}
}
impl ToCss for Resolution {
fn to_css<W>(&self, dest: &mut CssWriter<W>) -> fmt::Result
where
W: Write,
{
crate::values::serialize_specified_dimension(
self.value,
self.unit.as_str(),
self.was_calc,
dest,
)
}
}
impl Parse for Resolution {
fn parse<'i, 't>(
context: &ParserContext,
input: &mut Parser<'i, 't>,
) -> Result<Self, ParseError<'i>> {
let location = input.current_source_location();
match *input.next()? {
Token::Dimension {
value, ref unit, ..
} if value >= 0. => Self::parse_dimension(value, unit)
.map_err(|()| location.new_custom_error(StyleParseErrorKind::UnspecifiedError)),
Token::Function(ref name) => {
let function = CalcNode::math_function(context, name, location)?;
CalcNode::parse_resolution(context, input, function)
},
ref t => return Err(location.new_unexpected_token_error(t.clone())),
}
}
}
|
