Consider media attribute on link and style tags

Don't add a stylesheet if the current device does not match the media
query specified in a link or style tag.

components/script/dom/htmllinkelement.rs

@@ -7,7 +7,7 @@ use dom::attr::AttrHelpers;
 use dom::bindings::codegen::Bindings::HTMLLinkElementBinding;
 use dom::bindings::codegen::Bindings::HTMLLinkElementBinding::HTMLLinkElementMethods;
 use dom::bindings::codegen::InheritTypes::HTMLLinkElementDerived;
-use dom::bindings::codegen::InheritTypes::{ElementCast, HTMLElementCast};
+use dom::bindings::codegen::InheritTypes::{ElementCast, HTMLElementCast, NodeCast};
 use dom::bindings::js::{MutNullableJS, JSRef, Temporary, OptionalRootable};
 use dom::document::Document;
 use dom::domtokenlist::DOMTokenList;
@@ -20,6 +20,9 @@ use dom::virtualmethods::VirtualMethods;
 use dom::window::WindowHelpers;
 use layout_interface::{LayoutChan, Msg};
 use util::str::{DOMString, HTML_SPACE_CHARACTERS};
+use style::media_queries::parse_media_query_list;
+use style::node::TElement;
+use cssparser::Parser as CssParser;
 
 use std::ascii::AsciiExt;
 use std::borrow::ToOwned;
@@ -80,11 +83,16 @@ impl<'a> VirtualMethods for JSRef<'a, HTMLLinkElement> {
             s.after_set_attr(attr);
         }
 
+        let node: JSRef<Node> = NodeCast::from_ref(*self);
+        if !node.is_in_doc() {
+            return;
+        }
+
         let element: JSRef<Element> = ElementCast::from_ref(*self);
         let rel = get_attr(element, &atom!("rel"));
 
         match (rel, attr.local_name()) {
-            (ref rel, &atom!("href")) => {
+            (ref rel, &atom!("href")) | (ref rel, &atom!("media")) => {
                 if is_stylesheet(rel) {
                     self.handle_stylesheet_url(attr.value().as_slice());
                 }
@@ -131,8 +139,14 @@ impl<'a> PrivateHTMLLinkElementHelpers for JSRef<'a, HTMLLinkElement> {
         let window = window.r();
         match UrlParser::new().base_url(&window.get_url()).parse(href) {
             Ok(url) => {
+                let element: JSRef<Element> = ElementCast::from_ref(self);
+
+                let mq_str = element.get_attr(&ns!(""), &atom!("media")).unwrap_or("");
+                let mut css_parser = CssParser::new(&mq_str);
+                let media = parse_media_query_list(&mut css_parser);
+
                 let LayoutChan(ref layout_chan) = window.layout_chan();
-                layout_chan.send(Msg::LoadStylesheet(url)).unwrap();
+                layout_chan.send(Msg::LoadStylesheet(url, media)).unwrap();
             }
             Err(e) => debug!("Parsing url {} failed: {}", href, e)
         }

components/script/dom/htmlstyleelement.rs

@@ -4,11 +4,11 @@
 
 use dom::bindings::codegen::Bindings::HTMLStyleElementBinding;
 use dom::bindings::codegen::Bindings::NodeBinding::NodeMethods;
-use dom::bindings::codegen::InheritTypes::{HTMLElementCast, HTMLStyleElementDerived, NodeCast};
-use dom::bindings::js::{JSRef, Temporary};
+use dom::bindings::codegen::InheritTypes::{ElementCast, HTMLElementCast, HTMLStyleElementDerived, NodeCast};
+use dom::bindings::js::{JSRef, Temporary, OptionalRootable};
 use dom::document::Document;
 use dom::eventtarget::{EventTarget, EventTargetTypeId};
-use dom::element::ElementTypeId;
+use dom::element::{Element, ElementTypeId};
 use dom::htmlelement::{HTMLElement, HTMLElementTypeId};
 use dom::node::{Node, NodeHelpers, NodeTypeId, window_from_node};
 use dom::virtualmethods::VirtualMethods;
@@ -16,6 +16,9 @@ use dom::window::WindowHelpers;
 use layout_interface::{LayoutChan, Msg};
 use util::str::DOMString;
 use style::stylesheets::{Origin, Stylesheet};
+use style::media_queries::parse_media_query_list;
+use style::node::TElement;
+use cssparser::Parser as CssParser;
 
 #[dom_struct]
 pub struct HTMLStyleElement {
@@ -49,16 +52,21 @@ pub trait StyleElementHelpers {
 impl<'a> StyleElementHelpers for JSRef<'a, HTMLStyleElement> {
     fn parse_own_css(self) {
         let node: JSRef<Node> = NodeCast::from_ref(self);
+        let element: JSRef<Element> = ElementCast::from_ref(self);
         assert!(node.is_in_doc());
 
         let win = window_from_node(node).root();
         let win = win.r();
         let url = win.get_url();
 
+        let mq_str = element.get_attr(&ns!(""), &atom!("media")).unwrap_or("");
+        let mut css_parser = CssParser::new(&mq_str);
+        let media = parse_media_query_list(&mut css_parser);
+
         let data = node.GetTextContent().expect("Element.textContent must be a string");
         let sheet = Stylesheet::from_str(data.as_slice(), url, Origin::Author);
         let LayoutChan(ref layout_chan) = win.layout_chan();
-        layout_chan.send(Msg::AddStylesheet(sheet)).unwrap();
+        layout_chan.send(Msg::AddStylesheet(sheet, media)).unwrap();
     }
 }
 

components/script/layout_interface.rs

@@ -17,6 +17,7 @@ use std::any::Any;
 use std::sync::mpsc::{channel, Receiver, Sender};
 use std::boxed::BoxAny;
 use style::stylesheets::Stylesheet;
+use style::media_queries::MediaQueryList;
 use url::Url;
 
 pub use dom::node::TrustedNodeAddress;
@@ -24,10 +25,10 @@ pub use dom::node::TrustedNodeAddress;
 /// Asynchronous messages that script can send to layout.
 pub enum Msg {
     /// Adds the given stylesheet to the document.
-    AddStylesheet(Stylesheet),
+    AddStylesheet(Stylesheet, MediaQueryList),
 
     /// Adds the given stylesheet to the document.
-    LoadStylesheet(Url),
+    LoadStylesheet(Url, MediaQueryList),
 
     /// Puts a document into quirks mode, causing the quirks mode stylesheet to be loaded.
     SetQuirksMode,