style/values/specified/
time.rs

1/* This Source Code Form is subject to the terms of the Mozilla Public
2 * License, v. 2.0. If a copy of the MPL was not distributed with this
3 * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
4
5//! Specified time values.
6
7use crate::parser::{Parse, ParserContext};
8use crate::values::computed::time::Time as ComputedTime;
9use crate::values::computed::{Context, ToComputedValue};
10use crate::values::specified::calc::CalcNode;
11use crate::values::CSSFloat;
12use crate::Zero;
13use cssparser::{Parser, Token};
14use std::fmt::{self, Write};
15use style_traits::values::specified::AllowedNumericType;
16use style_traits::{CssWriter, ParseError, SpecifiedValueInfo, StyleParseErrorKind, ToCss};
17
18/// A time value according to CSS-VALUES § 6.2.
19#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, ToShmem)]
20pub struct Time {
21    seconds: CSSFloat,
22    unit: TimeUnit,
23    calc_clamping_mode: Option<AllowedNumericType>,
24}
25
26/// A time unit.
27#[derive(Clone, Copy, Debug, Eq, MallocSizeOf, PartialEq, ToShmem)]
28pub enum TimeUnit {
29    /// `s`
30    Second,
31    /// `ms`
32    Millisecond,
33}
34
35impl Time {
36    /// Returns a time value that represents `seconds` seconds.
37    pub fn from_seconds_with_calc_clamping_mode(
38        seconds: CSSFloat,
39        calc_clamping_mode: Option<AllowedNumericType>,
40    ) -> Self {
41        Time {
42            seconds,
43            unit: TimeUnit::Second,
44            calc_clamping_mode,
45        }
46    }
47
48    /// Returns a time value that represents `seconds` seconds.
49    pub fn from_seconds(seconds: CSSFloat) -> Self {
50        Self::from_seconds_with_calc_clamping_mode(seconds, None)
51    }
52
53    /// Returns the time in fractional seconds.
54    pub fn seconds(self) -> CSSFloat {
55        self.seconds
56    }
57
58    /// Returns the unit of the time.
59    #[inline]
60    pub fn unit(&self) -> &'static str {
61        match self.unit {
62            TimeUnit::Second => "s",
63            TimeUnit::Millisecond => "ms",
64        }
65    }
66
67    #[inline]
68    fn unitless_value(&self) -> CSSFloat {
69        match self.unit {
70            TimeUnit::Second => self.seconds,
71            TimeUnit::Millisecond => self.seconds * 1000.,
72        }
73    }
74
75    /// Parses a time according to CSS-VALUES § 6.2.
76    pub fn parse_dimension(value: CSSFloat, unit: &str) -> Result<Time, ()> {
77        let (seconds, unit) = match_ignore_ascii_case! { unit,
78            "s" => (value, TimeUnit::Second),
79            "ms" => (value / 1000.0, TimeUnit::Millisecond),
80            _ => return Err(())
81        };
82
83        Ok(Time {
84            seconds,
85            unit,
86            calc_clamping_mode: None,
87        })
88    }
89
90    fn parse_with_clamping_mode<'i, 't>(
91        context: &ParserContext,
92        input: &mut Parser<'i, 't>,
93        clamping_mode: AllowedNumericType,
94    ) -> Result<Self, ParseError<'i>> {
95        use style_traits::ParsingMode;
96
97        let location = input.current_source_location();
98        match *input.next()? {
99            // Note that we generally pass ParserContext to is_ok() to check
100            // that the ParserMode of the ParserContext allows all numeric
101            // values for SMIL regardless of clamping_mode, but in this Time
102            // value case, the value does not animate for SMIL at all, so we use
103            // ParsingMode::DEFAULT directly.
104            Token::Dimension {
105                value, ref unit, ..
106            } if clamping_mode.is_ok(ParsingMode::DEFAULT, value) => {
107                Time::parse_dimension(value, unit)
108                    .map_err(|()| location.new_custom_error(StyleParseErrorKind::UnspecifiedError))
109            },
110            Token::Function(ref name) => {
111                let function = CalcNode::math_function(context, name, location)?;
112                CalcNode::parse_time(context, input, clamping_mode, function)
113            },
114            ref t => return Err(location.new_unexpected_token_error(t.clone())),
115        }
116    }
117
118    /// Parses a non-negative time value.
119    pub fn parse_non_negative<'i, 't>(
120        context: &ParserContext,
121        input: &mut Parser<'i, 't>,
122    ) -> Result<Self, ParseError<'i>> {
123        Self::parse_with_clamping_mode(context, input, AllowedNumericType::NonNegative)
124    }
125}
126
127impl Zero for Time {
128    #[inline]
129    fn zero() -> Self {
130        Self::from_seconds(0.0)
131    }
132
133    #[inline]
134    fn is_zero(&self) -> bool {
135        // The unit doesn't matter, i.e. `s` and `ms` are the same for zero.
136        self.seconds == 0.0 && self.calc_clamping_mode.is_none()
137    }
138}
139
140impl ToComputedValue for Time {
141    type ComputedValue = ComputedTime;
142
143    fn to_computed_value(&self, _context: &Context) -> Self::ComputedValue {
144        let seconds = self
145            .calc_clamping_mode
146            .map_or(self.seconds(), |mode| mode.clamp(self.seconds()));
147
148        ComputedTime::from_seconds(crate::values::normalize(seconds))
149    }
150
151    fn from_computed_value(computed: &Self::ComputedValue) -> Self {
152        Time {
153            seconds: computed.seconds(),
154            unit: TimeUnit::Second,
155            calc_clamping_mode: None,
156        }
157    }
158}
159
160impl Parse for Time {
161    fn parse<'i, 't>(
162        context: &ParserContext,
163        input: &mut Parser<'i, 't>,
164    ) -> Result<Self, ParseError<'i>> {
165        Self::parse_with_clamping_mode(context, input, AllowedNumericType::All)
166    }
167}
168
169impl ToCss for Time {
170    fn to_css<W>(&self, dest: &mut CssWriter<W>) -> fmt::Result
171    where
172        W: Write,
173    {
174        crate::values::serialize_specified_dimension(
175            self.unitless_value(),
176            self.unit(),
177            self.calc_clamping_mode.is_some(),
178            dest,
179        )
180    }
181}
182
183impl SpecifiedValueInfo for Time {}
style/values/specified/time.rs

style/values/specified/
time.rs
