1 files changed, 183 insertions, 0 deletions
diff --git a/servo/components/style/values/specified/time.rs b/servo/components/style/values/specified/time.rs
new file mode 100644
index 0000000000..3061ebddcc
--- /dev/null
+++ b/servo/components/style/values/specified/time.rs
@@ -0,0 +1,183 @@
+/* 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/. */
+
+//! Specified time values.
+
+use crate::parser::{Parse, ParserContext};
+use crate::values::computed::time::Time as ComputedTime;
+use crate::values::computed::{Context, ToComputedValue};
+use crate::values::specified::calc::CalcNode;
+use crate::values::CSSFloat;
+use crate::Zero;
+use cssparser::{Parser, Token};
+use std::fmt::{self, Write};
+use style_traits::values::specified::AllowedNumericType;
+use style_traits::{CssWriter, ParseError, SpecifiedValueInfo, StyleParseErrorKind, ToCss};
+
+/// A time value according to CSS-VALUES § 6.2.
+#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, ToShmem)]
+pub struct Time {
+    seconds: CSSFloat,
+    unit: TimeUnit,
+    calc_clamping_mode: Option<AllowedNumericType>,
+}
+
+/// A time unit.
+#[derive(Clone, Copy, Debug, Eq, MallocSizeOf, PartialEq, ToShmem)]
+pub enum TimeUnit {
+    /// `s`
+    Second,
+    /// `ms`
+    Millisecond,
+}
+
+impl Time {
+    /// Returns a time value that represents `seconds` seconds.
+    pub fn from_seconds_with_calc_clamping_mode(
+        seconds: CSSFloat,
+        calc_clamping_mode: Option<AllowedNumericType>,
+    ) -> Self {
+        Time {
+            seconds,
+            unit: TimeUnit::Second,
+            calc_clamping_mode,
+        }
+    }
+
+    /// Returns a time value that represents `seconds` seconds.
+    pub fn from_seconds(seconds: CSSFloat) -> Self {
+        Self::from_seconds_with_calc_clamping_mode(seconds, None)
+    }
+
+    /// Returns the time in fractional seconds.
+    pub fn seconds(self) -> CSSFloat {
+        self.seconds
+    }
+
+    /// Returns the unit of the time.
+    #[inline]
+    pub fn unit(&self) -> &'static str {
+        match self.unit {
+            TimeUnit::Second => "s",
+            TimeUnit::Millisecond => "ms",
+        }
+    }
+
+    #[inline]
+    fn unitless_value(&self) -> CSSFloat {
+        match self.unit {
+            TimeUnit::Second => self.seconds,
+            TimeUnit::Millisecond => self.seconds * 1000.,
+        }
+    }
+
+    /// Parses a time according to CSS-VALUES § 6.2.
+    pub fn parse_dimension(value: CSSFloat, unit: &str) -> Result<Time, ()> {
+        let (seconds, unit) = match_ignore_ascii_case! { unit,
+            "s" => (value, TimeUnit::Second),
+            "ms" => (value / 1000.0, TimeUnit::Millisecond),
+            _ => return Err(())
+        };
+
+        Ok(Time {
+            seconds,
+            unit,
+            calc_clamping_mode: None,
+        })
+    }
+
+    fn parse_with_clamping_mode<'i, 't>(
+        context: &ParserContext,
+        input: &mut Parser<'i, 't>,
+        clamping_mode: AllowedNumericType,
+    ) -> Result<Self, ParseError<'i>> {
+        use style_traits::ParsingMode;
+
+        let location = input.current_source_location();
+        match *input.next()? {
+            // Note that we generally pass ParserContext to is_ok() to check
+            // that the ParserMode of the ParserContext allows all numeric
+            // values for SMIL regardless of clamping_mode, but in this Time
+            // value case, the value does not animate for SMIL at all, so we use
+            // ParsingMode::DEFAULT directly.
+            Token::Dimension {
+                value, ref unit, ..
+            } if clamping_mode.is_ok(ParsingMode::DEFAULT, value) => {
+                Time::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_time(context, input, clamping_mode, function)
+            },
+            ref t => return Err(location.new_unexpected_token_error(t.clone())),
+        }
+    }
+
+    /// Parses a non-negative time value.
+    pub fn parse_non_negative<'i, 't>(
+        context: &ParserContext,
+        input: &mut Parser<'i, 't>,
+    ) -> Result<Self, ParseError<'i>> {
+        Self::parse_with_clamping_mode(context, input, AllowedNumericType::NonNegative)
+    }
+}
+
+impl Zero for Time {
+    #[inline]
+    fn zero() -> Self {
+        Self::from_seconds(0.0)
+    }
+
+    #[inline]
+    fn is_zero(&self) -> bool {
+        // The unit doesn't matter, i.e. `s` and `ms` are the same for zero.
+        self.seconds == 0.0 && self.calc_clamping_mode.is_none()
+    }
+}
+
+impl ToComputedValue for Time {
+    type ComputedValue = ComputedTime;
+
+    fn to_computed_value(&self, _context: &Context) -> Self::ComputedValue {
+        let seconds = self
+            .calc_clamping_mode
+            .map_or(self.seconds(), |mode| mode.clamp(self.seconds()));
+
+        ComputedTime::from_seconds(crate::values::normalize(seconds))
+    }
+
+    fn from_computed_value(computed: &Self::ComputedValue) -> Self {
+        Time {
+            seconds: computed.seconds(),
+            unit: TimeUnit::Second,
+            calc_clamping_mode: None,
+        }
+    }
+}
+
+impl Parse for Time {
+    fn parse<'i, 't>(
+        context: &ParserContext,
+        input: &mut Parser<'i, 't>,
+    ) -> Result<Self, ParseError<'i>> {
+        Self::parse_with_clamping_mode(context, input, AllowedNumericType::All)
+    }
+}
+
+impl ToCss for Time {
+    fn to_css<W>(&self, dest: &mut CssWriter<W>) -> fmt::Result
+    where
+        W: Write,
+    {
+        crate::values::serialize_specified_dimension(
+            self.unitless_value(),
+            self.unit(),
+            self.calc_clamping_mode.is_some(),
+            dest,
+        )
+    }
+}
+
+impl SpecifiedValueInfo for Time {}