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/* 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
//! Generic types for CSS values related to <ratio>.
use std::fmt::{self, Write};
use style_traits::{CssWriter, ToCss};
use crate::{One, Zero};
/// A generic value for the `<ratio>` value.
#[derive(
Clone,
Copy,
Debug,
MallocSizeOf,
PartialEq,
SpecifiedValueInfo,
ToAnimatedValue,
ToComputedValue,
ToResolvedValue,
ToShmem,
)]
#[repr(C)]
pub struct Ratio<N>(pub N, pub N);
impl<N> ToCss for Ratio<N>
where
N: ToCss,
{
fn to_css<W>(&self, dest: &mut CssWriter<W>) -> fmt::Result
where
W: Write,
{
self.0.to_css(dest)?;
// Even though 1 could be omitted, we don't per
//
// The second <number> is optional, defaulting to 1. However,
// <ratio> is always serialized with both components.
//
//
// We serialize with spaces for consistency with all other
// slash-delimited things, see
dest.write_str(" / ")?;
self.1.to_css(dest)?;
Ok(())
}
}
impl<N> Ratio<N>
where
N: Zero + One,
{
/// Returns true if this is a degenerate ratio.
#[inline]
pub fn is_degenerate(&self) -> bool {
self.0.is_zero() || self.1.is_zero()
}
/// Returns the used value. A ratio of 0/0 behaves as the ratio 1/0.
pub fn used_value(self) -> Self {
if self.0.is_zero() && self.1.is_zero() {
Self(One::one(), Zero::zero())
} else {
self
}
}
}
impl<N> Zero for Ratio<N>
where
N: Zero + One,
{
fn zero() -> Self {
Self(Zero::zero(), One::one())
}
fn is_zero(&self) -> bool {
self.0.is_zero()
}
}