Translate attribute and its inheritance semantics

components/script/dom/element.rs

@@ -514,6 +514,25 @@ impl Element {
             debug_assert!(false, "Trying to detach a non-attached shadow root");
         }
     }
+
+    // https://html.spec.whatwg.org/multipage/#translation-mode
+    pub fn is_translate_enabled(&self) -> bool {
+        // TODO change this to local_name! when html5ever updates
+        let name = &LocalName::from("translate");
+        if self.has_attribute(name) {
+            match &*self.get_string_attribute(name) {
+                "yes" | "" => return true,
+                "no" => return false,
+                _ => {},
+            }
+        }
+        if let Some(parent) = self.upcast::<Node>().GetParentNode() {
+            if let Some(elem) = parent.downcast::<Element>() {
+                return elem.is_translate_enabled();
+            }
+        }
+        true // whatwg/html#5239
+    }
 }
 
 #[allow(unsafe_code)]

components/script/dom/htmlelement.rs

@@ -516,6 +516,23 @@ impl HTMLElementMethods for HTMLElement {
         // Step 7.
         Node::replace_all(Some(fragment.upcast()), self.upcast::<Node>());
     }
+
+    // https://html.spec.whatwg.org/multipage/#dom-translate
+    fn Translate(&self) -> bool {
+        self.upcast::<Element>().is_translate_enabled()
+    }
+
+    // https://html.spec.whatwg.org/multipage/#dom-translate
+    fn SetTranslate(&self, yesno: bool) {
+        self.upcast::<Element>().set_string_attribute(
+            // TODO change this to local_name! when html5ever updates
+            &LocalName::from("translate"),
+            match yesno {
+                true => DOMString::from("yes"),
+                false => DOMString::from("no"),
+            },
+        );
+    }
 }
 
 fn append_text_node_to_fragment(document: &Document, fragment: &DocumentFragment, text: String) {

components/script/dom/webidls/HTMLElement.webidl

@@ -12,8 +12,8 @@ interface HTMLElement : Element {
            attribute DOMString title;
   [CEReactions]
            attribute DOMString lang;
-  // [CEReactions]
-  //         attribute boolean translate;
+  [CEReactions]
+           attribute boolean translate;
   // [CEReactions]
   //         attribute DOMString dir;
   readonly attribute DOMStringMap dataset;