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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
//! A media query list:
//!
use super::{Device, MediaQuery, Qualifier};
use crate::context::QuirksMode;
use crate::error_reporting::ContextualParseError;
use crate::parser::ParserContext;
use crate::values::computed;
use cssparser::{Delimiter, Parser};
use cssparser::{ParserInput, Token};
use selectors::kleene_value::KleeneValue;
/// A type that encapsulates a media query list.
#[derive(Clone, MallocSizeOf, ToCss, ToShmem)]
#[css(comma, derive_debug)]
pub struct MediaList {
/// The list of media queries.
#[css(iterable)]
pub media_queries: Vec<MediaQuery>,
}
impl MediaList {
/// Parse a media query list from CSS.
///
/// Always returns a media query list. If any invalid media query is
/// found, the media query list is only filled with the equivalent of
/// "not all", see:
///
pub fn parse(context: &ParserContext, input: &mut Parser) -> Self {
if input.is_exhausted() {
return Self::empty();
}
let mut media_queries = vec![];
loop {
let start_position = input.position();
match input.parse_until_before(Delimiter::Comma, |i| MediaQuery::parse(context, i)) {
Ok(mq) => {
media_queries.push(mq);
},
Err(err) => {
media_queries.push(MediaQuery::never_matching());
let location = err.location;
let error = ContextualParseError::InvalidMediaRule(
input.slice_from(start_position),
err,
);
context.log_css_error(location, error);
},
}
match input.next() {
Ok(&Token::Comma) => {},
Ok(_) => unreachable!(),
Err(_) => break,
}
}
MediaList { media_queries }
}
/// Create an empty MediaList.
pub fn empty() -> Self {
MediaList {
media_queries: vec![],
}
}
/// Evaluate a whole `MediaList` against `Device`.
pub fn evaluate(&self, device: &Device, quirks_mode: QuirksMode) -> bool {
// Check if it is an empty media query list or any queries match.
if self.media_queries.is_empty() {
return true;
}
computed::Context::for_media_query_evaluation(device, quirks_mode, |context| {
self.media_queries.iter().any(|mq| {
let mut query_match = if mq.media_type.matches(device.media_type()) {
mq.condition
.as_ref()
.map_or(KleeneValue::True, |c| c.matches(context))
} else {
KleeneValue::False
};
// Apply the logical NOT qualifier to the result
if matches!(mq.qualifier, Some(Qualifier::Not)) {
query_match = !query_match;
}
query_match.to_bool(/* unknown = */ false)
})
})
}
/// Whether this `MediaList` contains no media queries.
pub fn is_empty(&self) -> bool {
self.media_queries.is_empty()
}
/// Whether this `MediaList` depends on the viewport size.
pub fn is_viewport_dependent(&self) -> bool {
self.media_queries.iter().any(|q| q.is_viewport_dependent())
}
/// Append a new media query item to the media list.
///
/// Returns true if added, false if fail to parse the medium string.
pub fn append_medium(&mut self, context: &ParserContext, new_medium: &str) -> bool {
let mut input = ParserInput::new(new_medium);
let mut parser = Parser::new(&mut input);
let new_query = match MediaQuery::parse(&context, &mut parser) {
Ok(query) => query,
Err(_) => {
return false;
},
};
// This algorithm doesn't actually matches the current spec,
// but it matches the behavior of Gecko and Edge.
self.media_queries.retain(|query| query != &new_query);
self.media_queries.push(new_query);
true
}
/// Delete a media query from the media list.
///
/// Returns true if found and deleted, false otherwise.
pub fn delete_medium(&mut self, context: &ParserContext, old_medium: &str) -> bool {
let mut input = ParserInput::new(old_medium);
let mut parser = Parser::new(&mut input);
let old_query = match MediaQuery::parse(context, &mut parser) {
Ok(query) => query,
Err(_) => {
return false;
},
};
let old_len = self.media_queries.len();
self.media_queries.retain(|query| query != &old_query);
old_len != self.media_queries.len()
}
}