servo/components/style/macros.rs
2017-05-20 14:48:04 +02:00

102 lines
3.6 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/. */
//! Various macro helpers.
macro_rules! define_numbered_css_keyword_enum {
($name: ident: $( $css: expr => $variant: ident = $value: expr ),+,) => {
define_numbered_css_keyword_enum!($name: $( $css => $variant = $value ),+);
};
($name: ident: $( $css: expr => $variant: ident = $value: expr ),+) => {
#[allow(non_camel_case_types, missing_docs)]
#[derive(Clone, Copy, Debug, Eq, Ord, PartialEq, PartialOrd)]
#[cfg_attr(feature = "servo", derive(HeapSizeOf, Deserialize, Serialize))]
pub enum $name {
$( $variant = $value ),+
}
impl $crate::parser::Parse for $name {
#[allow(missing_docs)]
fn parse(_context: &$crate::parser::ParserContext, input: &mut ::cssparser::Parser) -> Result<$name, ()> {
match_ignore_ascii_case! { &try!(input.expect_ident()),
$( $css => Ok($name::$variant), )+
_ => Err(())
}
}
}
impl ::style_traits::values::ToCss for $name {
fn to_css<W>(&self, dest: &mut W) -> ::std::fmt::Result
where W: ::std::fmt::Write,
{
match *self {
$( $name::$variant => dest.write_str($css) ),+
}
}
}
}
}
/// A macro for implementing `ComputedValueAsSpecified`, `Parse`
/// and `HasViewportPercentage` traits for the enums defined
/// using `define_css_keyword_enum` macro.
///
/// NOTE: We should either move `Parse` trait to `style_traits`
/// or `define_css_keyword_enum` macro to this crate, but that
/// may involve significant cleanup in both the crates.
macro_rules! add_impls_for_keyword_enum {
($name:ident) => {
impl $crate::parser::Parse for $name {
#[inline]
fn parse(_context: &$crate::parser::ParserContext,
input: &mut ::cssparser::Parser)
-> Result<Self, ()> {
$name::parse(input)
}
}
impl $crate::values::computed::ComputedValueAsSpecified for $name {}
no_viewport_percentage!($name);
};
}
macro_rules! define_keyword_type {
($name: ident, $css: expr) => {
#[derive(Clone, PartialEq, Copy)]
#[cfg_attr(feature = "servo", derive(HeapSizeOf))]
#[allow(missing_docs)]
pub struct $name;
impl ::style_traits::ToCss for $name {
fn to_css<W>(&self, dest: &mut W) -> ::std::fmt::Result where W: ::std::fmt::Write {
write!(dest, $css)
}
}
impl $crate::properties::animated_properties::Animatable for $name {
#[inline]
fn add_weighted(&self, _other: &Self, _self_progress: f64, _other_progress: f64)
-> Result<Self, ()> {
Ok($name)
}
}
impl fmt::Debug for $name {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
write!(f, $css)
}
}
impl $crate::parser::Parse for $name {
fn parse(_context: &$crate::parser::ParserContext,
input: &mut ::cssparser::Parser)
-> Result<$name, ()> {
input.expect_ident_matching($css).map(|_| $name)
}
}
impl $crate::values::computed::ComputedValueAsSpecified for $name {}
no_viewport_percentage!($name);
};
}