servo/components/style/values/generics/gecko.rs
Xidorn Quan 7fe7b2ffb1
style: Add a ValueInfo trait for exposing types needed by devtools.
Most of types just derive it using proc_macro directly. Some of value
types need manual impl.

In my current plan, this new trait will be used in bug 1434130 to expose
values as well.

Bug: 1455576
Reviewed-by: emilio
MozReview-Commit-ID: LI7fy45VkRw
2018-04-29 03:28:34 +02:00

35 lines
1 KiB
Rust

/* 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 http://mozilla.org/MPL/2.0/. */
//! Generic types for legacy Gecko-only properties that should probably be
//! unshipped at some point in the future.
/// A generic value for scroll snap points.
#[cfg_attr(feature = "gecko", derive(MallocSizeOf))]
#[derive(Clone, Copy, Debug, PartialEq, SpecifiedValueInfo, ToComputedValue,
ToCss)]
pub enum ScrollSnapPoint<LengthOrPercentage> {
/// `none`
None,
/// `repeat(<length-or-percentage>)`
#[css(function)]
Repeat(LengthOrPercentage),
}
impl<L> ScrollSnapPoint<L> {
/// Returns `none`.
#[inline]
pub fn none() -> Self {
ScrollSnapPoint::None
}
/// Returns the repeat argument, if any.
#[inline]
pub fn repeated(&self) -> Option<&L> {
match *self {
ScrollSnapPoint::None => None,
ScrollSnapPoint::Repeat(ref length) => Some(length),
}
}
}