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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
//! Common handling for the specified value CSS param() values.
use crate::custom_properties::VariableValue;
use crate::parser::{Parse, ParserContext};
use crate::values::fmt;
use crate::values::CssWriter;
use crate::{derives::*, values::DashedIdent};
use cssparser::Parser;
use std::fmt::Write;
use style_traits::arc_slice::ArcSlice;
use style_traits::owned_str::OwnedStr;
use style_traits::{ParseError, ToCss};
/// A struct to hold a specific '<declaration-value>?', since an empty value (param(--a, )) serializes differently than
/// a non-provided value (param(--a))
#[derive(
Clone,
Debug,
MallocSizeOf,
PartialEq,
SpecifiedValueInfo,
ToComputedValue,
ToResolvedValue,
ToShmem,
)]
#[repr(C, u8)]
pub enum LinkParamValueOrNone {
/// Handles the case when no value is provided at all: param(--a)
None,
/// Handles the cases for provided, or provided but empty, e.g. param(--a, blue) and param(--a, )
Specified(OwnedStr),
}
#[derive(
Clone,
Debug,
MallocSizeOf,
PartialEq,
SpecifiedValueInfo,
ToComputedValue,
ToResolvedValue,
ToShmem,
)]
#[repr(C)]
pub struct LinkParam {
/// link-parameters' param name, in the form of an <dashed-ident>: https://drafts.csswg.org/css-values-4/#typedef-dashed-ident
pub name: DashedIdent,
/// link-parameters' value, in the form of a <declaration-value>: https://drafts.csswg.org/css-syntax-3/#typedef-declaration-value
pub value: LinkParamValueOrNone,
}
///
/// We treat `none` as an empty slice and vis-versa
#[derive(
Clone,
Debug,
Default,
MallocSizeOf,
PartialEq,
SpecifiedValueInfo,
ToComputedValue,
ToCss,
ToResolvedValue,
ToShmem,
ToTyped,
)]
#[repr(C)]
#[css(comma)]
#[typed(skip_derive_fields)]
pub struct LinkParameters(
/// Slice of specified link-parameters properties: https://drafts.csswg.org/css-link-params-1/#link-param-prop
#[css(iterable, if_empty = "none")]
#[ignore_malloc_size_of = "Arc"]
pub ArcSlice<LinkParam>,
);
impl LinkParameters {
/// Returns the `none` value.
pub fn none() -> Self {
Self(ArcSlice::default())
}
}
impl Parse for LinkParameters {
fn parse<'i, 't>(
context: &ParserContext,
input: &mut Parser<'i, 't>,
) -> Result<Self, ParseError<'i>> {
if input.try_parse(|i| i.expect_ident_matching("none")).is_ok() {
return Ok(Self::none());
}
let params = input.parse_comma_separated(|input| {
input.expect_function_matching("param")?;
input.parse_nested_block(|input| {
let name = DashedIdent::parse(context, input)?;
// if a comma exists then parse it and set value as specified, even if no value provided
let value = if input.try_parse(|i| i.expect_comma()).is_ok() {
let parsed = VariableValue::parse(input, None, &context.url_data)?;
LinkParamValueOrNone::Specified(OwnedStr::from(parsed.css))
} else {
LinkParamValueOrNone::None
};
Ok(LinkParam { name, value })
})
})?;
Ok(Self(crate::ArcSlice::from_iter(params.into_iter())))
}
}
impl ToCss for LinkParam {
fn to_css<W>(&self, dest: &mut CssWriter<W>) -> fmt::Result
where
W: Write,
{
dest.write_str("param(")?;
self.name.to_css(dest)?;
if let LinkParamValueOrNone::Specified(param) = &self.value {
dest.write_str(", ")?;
if !param.is_empty() {
// Don't use to_css, instead write the raw CSS value without extra quoting, else serialization will include un-de-serializable quotes
dest.write_str(¶m)?;
}
}
dest.write_char(')')
}
}