style: Move MediaList to its own module.

And move the parsing from a free function to MediaList::parse.

Bug: 1468846
Reviewed-by: xidorn
MozReview-Commit-ID: 75ES6I2EEOE

components/style/media_queries/media_list.rs

@@ -0,0 +1,143 @@
+/* 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/. */
+
+//! A media query list:
+//!
+//! https://drafts.csswg.org/mediaqueries/#typedef-media-query-list
+
+use cssparser::{Delimiter, Parser};
+use cssparser::{ParserInput, Token};
+use context::QuirksMode;
+use error_reporting::{ContextualParseError, ParseErrorReporter};
+use parser::{ParserContext, ParserErrorContext};
+use super::{Device, MediaQuery, Qualifier};
+
+/// A type that encapsulates a media query list.
+#[css(comma)]
+#[derive(Clone, Debug, MallocSizeOf, ToCss)]
+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:
+    ///
+    /// <https://drafts.csswg.org/mediaqueries/#error-handling>
+    pub fn parse<R>(
+        context: &ParserContext,
+        input: &mut Parser,
+        error_reporter: &R,
+    ) -> MediaList
+    where
+        R: ParseErrorReporter,
+    {
+        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);
+                    let error_context = ParserErrorContext { error_reporter };
+                    context.log_css_error(&error_context, 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 (OR condition)
+        // https://drafts.csswg.org/mediaqueries-4/#mq-list
+        self.media_queries.is_empty() || self.media_queries.iter().any(|mq| {
+            let media_match = mq.media_type.matches(device.media_type());
+
+            // Check if all conditions match (AND condition)
+            let query_match = media_match &&
+                mq.expressions
+                    .iter()
+                    .all(|expression| expression.matches(&device, quirks_mode));
+
+            // Apply the logical NOT qualifier to the result
+            match mq.qualifier {
+                Some(Qualifier::Not) => !query_match,
+                _ => query_match,
+            }
+        })
+    }
+
+    /// Whether this `MediaList` contains no media queries.
+    pub fn is_empty(&self) -> bool {
+        self.media_queries.is_empty()
+    }
+
+    /// Append a new media query item to the media list.
+    /// <https://drafts.csswg.org/cssom/#dom-medialist-appendmedium>
+    ///
+    /// 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.
+        // See https://github.com/w3c/csswg-drafts/issues/697
+        self.media_queries.retain(|query| query != &new_query);
+        self.media_queries.push(new_query);
+        true
+    }
+
+    /// Delete a media query from the media list.
+    /// <https://drafts.csswg.org/cssom/#dom-medialist-deletemedium>
+    ///
+    /// 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()
+    }
+}

components/style/media_queries/mod.rs

@@ -7,40 +7,22 @@
 //! [mq]: https://drafts.csswg.org/mediaqueries/
 
 use Atom;
-use context::QuirksMode;
-use cssparser::{Delimiter, Parser};
-use cssparser::{ParserInput, Token};
-use error_reporting::{ContextualParseError, ParseErrorReporter};
-use parser::{ParserContext, ParserErrorContext};
+use cssparser::Parser;
+use parser::ParserContext;
 use selectors::parser::SelectorParseErrorKind;
 use std::fmt::{self, Write};
 use str::string_as_ascii_lowercase;
 use style_traits::{CssWriter, ParseError, StyleParseErrorKind, ToCss};
 use values::CustomIdent;
 
+mod media_list;
+
+pub use self::media_list::MediaList;
 #[cfg(feature = "servo")]
 pub use servo::media_queries::{Device, Expression};
 #[cfg(feature = "gecko")]
 pub use gecko::media_queries::{Device, Expression};
 
-/// A type that encapsulates a media query list.
-#[css(comma)]
-#[derive(Clone, Debug, MallocSizeOf, ToCss)]
-pub struct MediaList {
-    /// The list of media queries.
-    #[css(iterable)]
-    pub media_queries: Vec<MediaQuery>,
-}
-
-impl MediaList {
-    /// Create an empty MediaList.
-    pub fn empty() -> Self {
-        MediaList {
-            media_queries: vec![],
-        }
-    }
-}
-
 /// <https://drafts.csswg.org/mediaqueries/#mq-prefix>
 #[derive(Clone, Copy, Debug, Eq, MallocSizeOf, PartialEq, ToCss)]
 pub enum Qualifier {
@@ -233,117 +215,3 @@ impl MediaQuery {
         }
     }
 }
-
-/// 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:
-///
-/// <https://drafts.csswg.org/mediaqueries/#error-handling>
-pub fn parse_media_query_list<R>(
-    context: &ParserContext,
-    input: &mut Parser,
-    error_reporter: &R,
-) -> MediaList
-where
-    R: ParseErrorReporter,
-{
-    if input.is_exhausted() {
-        return MediaList::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);
-                let error_context = ParserErrorContext { error_reporter };
-                context.log_css_error(&error_context, location, error);
-            },
-        }
-
-        match input.next() {
-            Ok(&Token::Comma) => {},
-            Ok(_) => unreachable!(),
-            Err(_) => break,
-        }
-    }
-
-    MediaList {
-        media_queries: media_queries,
-    }
-}
-
-impl MediaList {
-    /// 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 (OR condition)
-        // https://drafts.csswg.org/mediaqueries-4/#mq-list
-        self.media_queries.is_empty() || self.media_queries.iter().any(|mq| {
-            let media_match = mq.media_type.matches(device.media_type());
-
-            // Check if all conditions match (AND condition)
-            let query_match = media_match &&
-                mq.expressions
-                    .iter()
-                    .all(|expression| expression.matches(&device, quirks_mode));
-
-            // Apply the logical NOT qualifier to the result
-            match mq.qualifier {
-                Some(Qualifier::Not) => !query_match,
-                _ => query_match,
-            }
-        })
-    }
-
-    /// Whether this `MediaList` contains no media queries.
-    pub fn is_empty(&self) -> bool {
-        self.media_queries.is_empty()
-    }
-
-    /// Append a new media query item to the media list.
-    /// <https://drafts.csswg.org/cssom/#dom-medialist-appendmedium>
-    ///
-    /// 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.
-        // See https://github.com/w3c/csswg-drafts/issues/697
-        self.media_queries.retain(|query| query != &new_query);
-        self.media_queries.push(new_query);
-        true
-    }
-
-    /// Delete a media query from the media list.
-    /// <https://drafts.csswg.org/cssom/#dom-medialist-deletemedium>
-    ///
-    /// 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()
-    }
-}

components/style/stylesheets/rule_parser.rs

@@ -10,7 +10,7 @@ use cssparser::{AtRuleParser, AtRuleType, Parser, QualifiedRuleParser, RuleListP
 use cssparser::{BasicParseError, BasicParseErrorKind, CowRcStr, SourceLocation};
 use error_reporting::{ContextualParseError, ParseErrorReporter};
 use font_face::parse_font_face_block;
-use media_queries::{parse_media_query_list, MediaList};
+use media_queries::MediaList;
 use parser::{Parse, ParserContext, ParserErrorContext};
 use properties::parse_property_declaration_list;
 use selector_parser::{SelectorImpl, SelectorParser};
@@ -197,8 +197,11 @@ impl<'a, 'i, R: ParseErrorReporter> AtRuleParser<'i> for TopLevelRuleParser<'a,
                 let url_string = input.expect_url_or_string()?.as_ref().to_owned();
                 let url = CssUrl::parse_from_string(url_string, &self.context);
 
-                let media = parse_media_query_list(&self.context, input,
-                                                   self.error_context.error_reporter);
+                let media = MediaList::parse(
+                    &self.context,
+                    input,
+                    self.error_context.error_reporter,
+                );
                 let media = Arc::new(self.shared_lock.wrap(media));
 
                 let prelude = AtRuleNonBlockPrelude::Import(url, media, location);
@@ -380,8 +383,11 @@ impl<'a, 'b, 'i, R: ParseErrorReporter> AtRuleParser<'i> for NestedRuleParser<'a
 
         match_ignore_ascii_case! { &*name,
             "media" => {
-                let media_queries = parse_media_query_list(self.context, input,
-                                                           self.error_context.error_reporter);
+                let media_queries = MediaList::parse(
+                    self.context,
+                    input,
+                    self.error_context.error_reporter,
+                );
                 let arc = Arc::new(self.shared_lock.wrap(media_queries));
                 Ok(AtRuleType::WithBlock(AtRuleBlockPrelude::Media(arc, location)))
             },