Handle dynamic font color change

components/script/dom/document.rs

@@ -88,6 +88,7 @@ use dom::touchevent::TouchEvent;
 use dom::touchlist::TouchList;
 use dom::treewalker::TreeWalker;
 use dom::uievent::UIEvent;
+use dom::virtualmethods::vtable_for;
 use dom::webglcontextevent::WebGLContextEvent;
 use dom::window::{ReflowReason, Window};
 use dom::windowproxy::WindowProxy;
@@ -2499,10 +2500,7 @@ impl Document {
             entry.hint.insert(RESTYLE_STYLE_ATTRIBUTE);
         }
 
-        // FIXME(emilio): This should become something like
-        // element.is_attribute_mapped(attr.local_name()).
-        if attr.local_name() == &local_name!("width") ||
-           attr.local_name() == &local_name!("height") {
+        if vtable_for(el.upcast()).attribute_is_mapped(attr) {
             entry.hint.insert(RESTYLE_SELF);
         }
 

components/script/dom/element.rs

@@ -2303,6 +2303,16 @@ impl VirtualMethods for Element {
         Some(self.upcast::<Node>() as &VirtualMethods)
     }
 
+    fn attribute_is_mapped(&self, attr: &Attr) -> bool {
+        // FIXME: This should be more fine-grained, not all elements care about these.
+        if attr.local_name() == &local_name!("width") ||
+           attr.local_name() == &local_name!("height") {
+            return true;
+        }
+
+        self.super_type().unwrap().attribute_is_mapped(attr)
+    }
+
     fn attribute_mutated(&self, attr: &Attr, mutation: AttributeMutation) {
         self.super_type().unwrap().attribute_mutated(attr, mutation);
         let node = self.upcast::<Node>();

components/script/dom/htmlfontelement.rs

@@ -3,6 +3,7 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 use cssparser::RGBA;
+use dom::attr::Attr;
 use dom::bindings::codegen::Bindings::HTMLFontElementBinding;
 use dom::bindings::codegen::Bindings::HTMLFontElementBinding::HTMLFontElementMethods;
 use dom::bindings::inheritance::Castable;
@@ -70,6 +71,15 @@ impl VirtualMethods for HTMLFontElement {
         Some(self.upcast::<HTMLElement>() as &VirtualMethods)
     }
 
+    fn attribute_is_mapped(&self, attr: &Attr) -> bool {
+        if attr.local_name() == &local_name!("color") {
+            return true;
+        }
+
+        // FIXME: Should also return true for `size` and `face` changes!
+        self.super_type().unwrap().attribute_is_mapped(attr)
+    }
+
     fn parse_plain_attribute(&self, name: &LocalName, value: DOMString) -> AttrValue {
         match name {
             &local_name!("face") => AttrValue::from_atomic(value.into()),

components/script/dom/virtualmethods.rs

@@ -70,6 +70,15 @@ pub trait VirtualMethods {
         }
     }
 
+    /// Returns `true` if given attribute `attr` affects style of the
+    /// given element.
+    fn attribute_is_mapped(&self, attr: &Attr) -> bool {
+        match self.super_type() {
+            Some(s) => s.attribute_is_mapped(attr),
+            None => false
+        }
+    }
+
     /// Returns the right AttrValue variant for the attribute with name `name`
     /// on this element.
     fn parse_plain_attribute(&self, name: &LocalName, value: DOMString) -> AttrValue {

tests/wpt/mozilla/meta/MANIFEST.json

@@ -2231,6 +2231,18 @@
      {}
     ]
    ],
+   "css/font_color_attribute_change.html": [
+    [
+     "/_mozilla/css/font_color_attribute_change.html",
+     [
+      [
+       "/_mozilla/css/font_color_attribute_change_ref.html",
+       "=="
+      ]
+     ],
+     {}
+    ]
+   ],
    "css/font_face_attribute.html": [
     [
      "/_mozilla/css/font_face_attribute.html",
@@ -8768,6 +8780,11 @@
      {}
     ]
    ],
+   "css/font_color_attribute_change_ref.html": [
+    [
+     {}
+    ]
+   ],
    "css/font_color_attribute_ref.html": [
     [
      {}
@@ -24031,6 +24048,14 @@
    "c26b839b729cae2d01ba7f2588852170bcc0b82e",
    "reftest"
   ],
+  "css/font_color_attribute_change.html": [
+   "87c9ff1745eaecbbf2ac61d5d37a9c7e82c729a9",
+   "reftest"
+  ],
+  "css/font_color_attribute_change_ref.html": [
+   "0c84fb819c07853ec125e52df465701ad6da7424",
+   "support"
+  ],
   "css/font_color_attribute_ref.html": [
    "4a07819ffd7c7629ee13f428cf7243c99f3dfc63",
    "support"

tests/wpt/mozilla/tests/css/font_color_attribute_change.html

@@ -0,0 +1,15 @@
+<!doctype html>
+<html>
+  <head>
+    <meta charset="utf-8">
+    <title></title>
+    <link rel="match" href="font_color_attribute_change_ref.html">
+  </head>
+  <body>
+    <font color="red">I should be green</font>
+    <script>
+      document.body.offsetTop;
+      document.querySelector("font").setAttribute("color", "green");
+    </script>
+  </body>
+</html>

tests/wpt/mozilla/tests/css/font_color_attribute_change_ref.html

@@ -0,0 +1,9 @@
+<!doctype html>
+<html>
+  <head>
+    <title></title>
+  </head>
+  <body>
+    <font color="green">I should be green</font>
+  </body>
+</html>