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::derives::*;
8use crate::parser::{Parse, ParserContext};
9use crate::values::computed::time::Time as ComputedTime;
10use crate::values::computed::{Context, ToComputedValue};
11use crate::values::specified::calc::CalcNode;
12use crate::values::CSSFloat;
13use crate::Zero;
14use cssparser::{match_ignore_ascii_case, Parser, Token};
15use std::fmt::{self, Write};
16use style_traits::values::specified::AllowedNumericType;
17use style_traits::{CssWriter, ParseError, SpecifiedValueInfo, StyleParseErrorKind, ToCss};
18
19/// A time value according to CSS-VALUES § 6.2.
20#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, ToShmem)]
21pub struct Time {
22    seconds: CSSFloat,
23    unit: TimeUnit,
24    calc_clamping_mode: Option<AllowedNumericType>,
25}
26
27/// A time unit.
28#[derive(Clone, Copy, Debug, Eq, MallocSizeOf, PartialEq, ToShmem)]
29pub enum TimeUnit {
30    /// `s`
31    Second,
32    /// `ms`
33    Millisecond,
34}
35
36impl Time {
37    /// Returns a time value that represents `seconds` seconds.
38    pub fn from_seconds_with_calc_clamping_mode(
39        seconds: CSSFloat,
40        calc_clamping_mode: Option<AllowedNumericType>,
41    ) -> Self {
42        Time {
43            seconds,
44            unit: TimeUnit::Second,
45            calc_clamping_mode,
46        }
47    }
48
49    /// Returns a time value that represents `seconds` seconds.
50    pub fn from_seconds(seconds: CSSFloat) -> Self {
51        Self::from_seconds_with_calc_clamping_mode(seconds, None)
52    }
53
54    /// Returns the time in fractional seconds.
55    pub fn seconds(self) -> CSSFloat {
56        self.seconds
57    }
58
59    /// Returns the unit of the time.
60    #[inline]
61    pub fn unit(&self) -> &'static str {
62        match self.unit {
63            TimeUnit::Second => "s",
64            TimeUnit::Millisecond => "ms",
65        }
66    }
67
68    #[inline]
69    fn unitless_value(&self) -> CSSFloat {
70        match self.unit {
71            TimeUnit::Second => self.seconds,
72            TimeUnit::Millisecond => self.seconds * 1000.,
73        }
74    }
75
76    /// Parses a time according to CSS-VALUES § 6.2.
77    pub fn parse_dimension(value: CSSFloat, unit: &str) -> Result<Time, ()> {
78        let (seconds, unit) = match_ignore_ascii_case! { unit,
79            "s" => (value, TimeUnit::Second),
80            "ms" => (value / 1000.0, TimeUnit::Millisecond),
81            _ => return Err(())
82        };
83
84        Ok(Time {
85            seconds,
86            unit,
87            calc_clamping_mode: None,
88        })
89    }
90
91    fn parse_with_clamping_mode<'i, 't>(
92        context: &ParserContext,
93        input: &mut Parser<'i, 't>,
94        clamping_mode: AllowedNumericType,
95    ) -> Result<Self, ParseError<'i>> {
96        use style_traits::ParsingMode;
97
98        let location = input.current_source_location();
99        match *input.next()? {
100            // Note that we generally pass ParserContext to is_ok() to check
101            // that the ParserMode of the ParserContext allows all numeric
102            // values for SMIL regardless of clamping_mode, but in this Time
103            // value case, the value does not animate for SMIL at all, so we use
104            // ParsingMode::DEFAULT directly.
105            Token::Dimension {
106                value, ref unit, ..
107            } if clamping_mode.is_ok(ParsingMode::DEFAULT, value) => {
108                Time::parse_dimension(value, unit)
109                    .map_err(|()| location.new_custom_error(StyleParseErrorKind::UnspecifiedError))
110            },
111            Token::Function(ref name) => {
112                let function = CalcNode::math_function(context, name, location)?;
113                CalcNode::parse_time(context, input, clamping_mode, function)
114            },
115            ref t => return Err(location.new_unexpected_token_error(t.clone())),
116        }
117    }
118
119    /// Parses a non-negative time value.
120    pub fn parse_non_negative<'i, 't>(
121        context: &ParserContext,
122        input: &mut Parser<'i, 't>,
123    ) -> Result<Self, ParseError<'i>> {
124        Self::parse_with_clamping_mode(context, input, AllowedNumericType::NonNegative)
125    }
126}
127
128impl Zero for Time {
129    #[inline]
130    fn zero() -> Self {
131        Self::from_seconds(0.0)
132    }
133
134    #[inline]
135    fn is_zero(&self) -> bool {
136        // The unit doesn't matter, i.e. `s` and `ms` are the same for zero.
137        self.seconds == 0.0 && self.calc_clamping_mode.is_none()
138    }
139}
140
141impl ToComputedValue for Time {
142    type ComputedValue = ComputedTime;
143
144    fn to_computed_value(&self, _context: &Context) -> Self::ComputedValue {
145        let seconds = self
146            .calc_clamping_mode
147            .map_or(self.seconds(), |mode| mode.clamp(self.seconds()));
148
149        ComputedTime::from_seconds(crate::values::normalize(seconds))
150    }
151
152    fn from_computed_value(computed: &Self::ComputedValue) -> Self {
153        Time {
154            seconds: computed.seconds(),
155            unit: TimeUnit::Second,
156            calc_clamping_mode: None,
157        }
158    }
159}
160
161impl Parse for Time {
162    fn parse<'i, 't>(
163        context: &ParserContext,
164        input: &mut Parser<'i, 't>,
165    ) -> Result<Self, ParseError<'i>> {
166        Self::parse_with_clamping_mode(context, input, AllowedNumericType::All)
167    }
168}
169
170impl ToCss for Time {
171    fn to_css<W>(&self, dest: &mut CssWriter<W>) -> fmt::Result
172    where
173        W: Write,
174    {
175        crate::values::serialize_specified_dimension(
176            self.unitless_value(),
177            self.unit(),
178            self.calc_clamping_mode.is_some(),
179            dest,
180        )
181    }
182}
183
184impl SpecifiedValueInfo for Time {}
style/values/specified/time.rs

style/values/specified/
time.rs
