Mirrors/servo
1
0
Fork 0
mirror of https://github.com/servo/servo.git synced 2025-08-06 14:10:11 +01:00
Code Issues Projects Releases Packages Wiki Activity

Document how style traits can be derived

Browse source
This commit is contained in:
Anthony Ramine 2017-08-28 09:37:25 +02:00
parent 41c3be54ea
commit ba4136b5a8
4 changed files with 44 additions and 3 deletions
Download patch file Download diff file Expand all files Collapse all files

11
components/style/values/distance.rs
View file

@ -10,6 +10,17 @@ use std::iter::Sum;
use std::ops::Add;
/// A trait to compute squared distances between two animatable values.
///
/// This trait is derivable with `#[derive(ComputeSquaredDistance)]`. The derived
/// implementation uses a `match` expression with identical patterns for both
/// `self` and `other`, calling `ComputeSquaredDistance::compute_squared_distance`
/// on each fields of the values.
///
/// If a variant is annotated with `#[animation(error)]`, the corresponding
/// `match` arm is not generated.
///
/// If the two values are not similar, an error is returned unless a fallback
/// function has been specified through `#[distance(fallback)]`.
pub trait ComputeSquaredDistance {
/// Computes the squared distance between two animatable values.
fn compute_squared_distance(&self, other: &Self) -> Result<SquaredDistance, ()>;