Auto merge of #7965 - frewsxcv:labelable-elements-label-attribute, r=nox

Implement 'labels' attribute on 'labelable elements'



<!-- Reviewable:start -->
[<img src="https://reviewable.io/review_button.png" height=40 alt="Review on Reviewable"/>](https://reviewable.io/reviews/servo/servo/7965)
<!-- Reviewable:end -->

components/script/dom/htmlbuttonelement.rs

@@ -17,6 +17,7 @@ use dom::htmlfieldsetelement::HTMLFieldSetElement;
 use dom::htmlformelement::{FormControl, FormSubmitter};
 use dom::htmlformelement::{SubmittedFrom, HTMLFormElement};
 use dom::node::{Node, document_from_node, window_from_node};
+use dom::nodelist::NodeList;
 use dom::validitystate::ValidityState;
 use dom::virtualmethods::VirtualMethods;
 use selectors::states::*;
@@ -131,6 +132,11 @@ impl HTMLButtonElementMethods for HTMLButtonElement {
 
     // https://html.spec.whatwg.org/multipage/#dom-button-value
     make_setter!(SetValue, "value");
+
+    // https://html.spec.whatwg.org/multipage/#dom-lfe-labels
+    fn Labels(&self) -> Root<NodeList> {
+        self.upcast::<HTMLElement>().labels()
+    }
 }
 
 impl VirtualMethods for HTMLButtonElement {

components/script/dom/htmlelement.rs

@@ -4,6 +4,7 @@
 
 use dom::attr::Attr;
 use dom::attr::AttrValue;
+use dom::bindings::codegen::Bindings::ElementBinding::ElementMethods;
 use dom::bindings::codegen::Bindings::EventHandlerBinding::EventHandlerNonNull;
 use dom::bindings::codegen::Bindings::HTMLElementBinding;
 use dom::bindings::codegen::Bindings::HTMLElementBinding::HTMLElementMethods;
@@ -12,7 +13,7 @@ use dom::bindings::codegen::Bindings::WindowBinding::WindowMethods;
 use dom::bindings::codegen::InheritTypes::{ElementTypeId, HTMLElementTypeId, NodeTypeId};
 use dom::bindings::conversions::Castable;
 use dom::bindings::error::{Error, ErrorResult};
-use dom::bindings::js::{JS, MutNullableHeap, Root};
+use dom::bindings::js::{JS, MutNullableHeap, Root, RootedReference};
 use dom::bindings::utils::Reflectable;
 use dom::cssstyledeclaration::{CSSModificationAccess, CSSStyleDeclaration};
 use dom::document::Document;
@@ -23,8 +24,10 @@ use dom::htmlbodyelement::HTMLBodyElement;
 use dom::htmlframesetelement::HTMLFrameSetElement;
 use dom::htmlhtmlelement::HTMLHtmlElement;
 use dom::htmlinputelement::HTMLInputElement;
+use dom::htmllabelelement::HTMLLabelElement;
 use dom::node::{Node, SEQUENTIALLY_FOCUSABLE};
 use dom::node::{document_from_node, window_from_node};
+use dom::nodelist::NodeList;
 use dom::virtualmethods::VirtualMethods;
 use msg::constellation_msg::FocusType;
 use selectors::states::*;
@@ -365,6 +368,45 @@ impl HTMLElement {
             to_camel_case(&raw_name)
         }).collect()
     }
+
+    // https://html.spec.whatwg.org/multipage/#dom-lfe-labels
+    pub fn labels(&self) -> Root<NodeList> {
+        debug_assert!(self.is_labelable_element());
+
+        let element = self.upcast::<Element>();
+        let window = window_from_node(element);
+
+        // Traverse ancestors for implicitly associated <label> elements
+        // https://html.spec.whatwg.org/multipage/#the-label-element:attr-label-for-4
+        let ancestors =
+            self.upcast::<Node>()
+                .ancestors()
+                .filter_map(Root::downcast::<HTMLElement>)
+                // If we reach a labelable element, we have a guarantee no ancestors above it
+                // will be a label for this HTMLElement
+                .take_while(|elem| !elem.is_labelable_element())
+                .filter_map(Root::downcast::<HTMLLabelElement>)
+                .filter(|elem| !elem.upcast::<Element>().has_attribute(&atom!("for")))
+                .filter(|elem| elem.first_labelable_descendant().r() == Some(self))
+                .map(Root::upcast::<Node>);
+
+        let id = element.Id();
+        let id = match &id as &str {
+            "" => return NodeList::new_simple_list(window.r(), ancestors),
+            id => id,
+        };
+
+        // Traverse entire tree for <label> elements with `for` attribute matching `id`
+        let root_element = element.get_root_element();
+        let root_node = root_element.upcast::<Node>();
+        let children = root_node.traverse_preorder()
+                                .filter_map(Root::downcast::<Element>)
+                                .filter(|elem| elem.is::<HTMLLabelElement>())
+                                .filter(|elem| elem.get_string_attribute(&atom!("for")) == id)
+                                .map(Root::upcast::<Node>);
+
+        NodeList::new_simple_list(window.r(), children.chain(ancestors))
+    }
 }
 
 impl VirtualMethods for HTMLElement {

components/script/dom/htmlinputelement.rs

@@ -25,6 +25,7 @@ use dom::htmlformelement::{ResetFrom, SubmittedFrom};
 use dom::keyboardevent::KeyboardEvent;
 use dom::node::{Node, NodeDamage};
 use dom::node::{document_from_node, window_from_node};
+use dom::nodelist::NodeList;
 use dom::virtualmethods::VirtualMethods;
 use msg::constellation_msg::ConstellationChan;
 use selectors::states::*;
@@ -333,6 +334,16 @@ impl HTMLInputElementMethods for HTMLInputElement {
     fn SetIndeterminate(&self, val: bool) {
         self.upcast::<Element>().set_state(IN_INDETERMINATE_STATE, val)
     }
+
+    // https://html.spec.whatwg.org/multipage/#dom-lfe-labels
+    fn Labels(&self) -> Root<NodeList> {
+        if self.Type() == "hidden" {
+            let window = window_from_node(self);
+            NodeList::empty(&window)
+        } else {
+            self.upcast::<HTMLElement>().labels()
+        }
+    }
 }
 
 

components/script/dom/htmllabelelement.rs

@@ -123,7 +123,7 @@ impl VirtualMethods for HTMLLabelElement {
 }
 
 impl HTMLLabelElement {
-    fn first_labelable_descendant(&self) -> Option<Root<HTMLElement>> {
+    pub fn first_labelable_descendant(&self) -> Option<Root<HTMLElement>> {
         self.upcast::<Node>()
             .traverse_preorder()
             .filter_map(Root::downcast::<HTMLElement>)

components/script/dom/htmlmeterelement.rs

@@ -2,11 +2,13 @@
  * 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/. */
 
-use dom::bindings::codegen::Bindings::HTMLMeterElementBinding;
+use dom::bindings::codegen::Bindings::HTMLMeterElementBinding::{self, HTMLMeterElementMethods};
+use dom::bindings::conversions::Castable;
 use dom::bindings::js::Root;
 use dom::document::Document;
 use dom::htmlelement::HTMLElement;
 use dom::node::Node;
+use dom::nodelist::NodeList;
 use util::str::DOMString;
 
 #[dom_struct]
@@ -31,3 +33,10 @@ impl HTMLMeterElement {
         Node::reflect_node(box element, document, HTMLMeterElementBinding::Wrap)
     }
 }
+
+impl HTMLMeterElementMethods for HTMLMeterElement {
+    // https://html.spec.whatwg.org/multipage/#dom-lfe-labels
+    fn Labels(&self) -> Root<NodeList> {
+        self.upcast::<HTMLElement>().labels()
+    }
+}

components/script/dom/htmloutputelement.rs

@@ -4,11 +4,13 @@
 
 use dom::bindings::codegen::Bindings::HTMLOutputElementBinding;
 use dom::bindings::codegen::Bindings::HTMLOutputElementBinding::HTMLOutputElementMethods;
+use dom::bindings::conversions::Castable;
 use dom::bindings::js::Root;
 use dom::document::Document;
 use dom::htmlelement::HTMLElement;
 use dom::htmlformelement::{FormControl, HTMLFormElement};
 use dom::node::{Node, window_from_node};
+use dom::nodelist::NodeList;
 use dom::validitystate::ValidityState;
 use util::str::DOMString;
 
@@ -47,6 +49,11 @@ impl HTMLOutputElementMethods for HTMLOutputElement {
     fn GetForm(&self) -> Option<Root<HTMLFormElement>> {
         self.form_owner()
     }
+
+    // https://html.spec.whatwg.org/multipage/#dom-lfe-labels
+    fn Labels(&self) -> Root<NodeList> {
+        self.upcast::<HTMLElement>().labels()
+    }
 }
 
 impl FormControl for HTMLOutputElement {}

components/script/dom/htmlprogresselement.rs

@@ -2,11 +2,13 @@
  * 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/. */
 
-use dom::bindings::codegen::Bindings::HTMLProgressElementBinding;
+use dom::bindings::codegen::Bindings::HTMLProgressElementBinding::{self, HTMLProgressElementMethods};
+use dom::bindings::conversions::Castable;
 use dom::bindings::js::Root;
 use dom::document::Document;
 use dom::htmlelement::HTMLElement;
 use dom::node::Node;
+use dom::nodelist::NodeList;
 use util::str::DOMString;
 
 #[dom_struct]
@@ -32,3 +34,10 @@ impl HTMLProgressElement {
         Node::reflect_node(box element, document, HTMLProgressElementBinding::Wrap)
     }
 }
+
+impl HTMLProgressElementMethods for HTMLProgressElement {
+    // https://html.spec.whatwg.org/multipage/#dom-lfe-labels
+    fn Labels(&self) -> Root<NodeList> {
+        self.upcast::<HTMLElement>().labels()
+    }
+}

components/script/dom/htmlselectelement.rs

@@ -17,6 +17,7 @@ use dom::htmlfieldsetelement::HTMLFieldSetElement;
 use dom::htmlformelement::{FormControl, HTMLFormElement};
 use dom::htmloptionelement::HTMLOptionElement;
 use dom::node::{Node, window_from_node};
+use dom::nodelist::NodeList;
 use dom::validitystate::ValidityState;
 use dom::virtualmethods::VirtualMethods;
 use selectors::states::*;
@@ -158,6 +159,11 @@ impl HTMLSelectElementMethods for HTMLSelectElement {
             "select-one".to_owned()
         }
     }
+
+    // https://html.spec.whatwg.org/multipage/#dom-lfe-labels
+    fn Labels(&self) -> Root<NodeList> {
+        self.upcast::<HTMLElement>().labels()
+    }
 }
 
 impl VirtualMethods for HTMLSelectElement {

components/script/dom/htmltextareaelement.rs

@@ -22,6 +22,7 @@ use dom::htmlformelement::{FormControl, HTMLFormElement};
 use dom::keyboardevent::KeyboardEvent;
 use dom::node::{ChildrenMutation, Node, NodeDamage};
 use dom::node::{document_from_node, window_from_node};
+use dom::nodelist::NodeList;
 use dom::virtualmethods::VirtualMethods;
 use msg::constellation_msg::ConstellationChan;
 use script_task::ScriptTaskEventCategory::InputEvent;
@@ -205,6 +206,11 @@ impl HTMLTextAreaElementMethods for HTMLTextAreaElement {
 
         self.force_relayout();
     }
+
+    // https://html.spec.whatwg.org/multipage/#dom-lfe-labels
+    fn Labels(&self) -> Root<NodeList> {
+        self.upcast::<HTMLElement>().labels()
+    }
 }
 
 

components/script/dom/nodelist.rs

@@ -51,6 +51,10 @@ impl NodeList {
     pub fn new_child_list(window: &Window, node: &Node) -> Root<NodeList> {
         NodeList::new(window, NodeListType::Children(ChildrenList::new(node)))
     }
+
+    pub fn empty(window: &Window) -> Root<NodeList> {
+        NodeList::new(window, NodeListType::Simple(vec![]))
+    }
 }
 
 impl NodeListMethods for NodeList {

components/script/dom/webidls/HTMLButtonElement.webidl

@@ -25,5 +25,5 @@ interface HTMLButtonElement : HTMLElement {
   //boolean reportValidity();
   //void setCustomValidity(DOMString error);
 
-  //readonly attribute NodeList labels;
+  readonly attribute NodeList labels;
 };

components/script/dom/webidls/HTMLInputElement.webidl

@@ -57,7 +57,7 @@ interface HTMLInputElement : HTMLElement {
   //boolean reportValidity();
   //void setCustomValidity(DOMString error);
 
-  //readonly attribute NodeList labels;
+  readonly attribute NodeList labels;
 
   //void select();
   //         attribute unsigned long selectionStart;

components/script/dom/webidls/HTMLMeterElement.webidl

@@ -11,5 +11,5 @@ interface HTMLMeterElement : HTMLElement {
   //         attribute double low;
   //         attribute double high;
   //         attribute double optimum;
-  //readonly attribute NodeList labels;
+  readonly attribute NodeList labels;
 };

components/script/dom/webidls/HTMLOutputElement.webidl

@@ -20,5 +20,5 @@ interface HTMLOutputElement : HTMLElement {
   //boolean reportValidity();
   //void setCustomValidity(DOMString error);
 
-  //readonly attribute NodeList labels;
+  readonly attribute NodeList labels;
 };

components/script/dom/webidls/HTMLProgressElement.webidl

@@ -8,5 +8,5 @@ interface HTMLProgressElement : HTMLElement {
   //         attribute double value;
   //         attribute double max;
   //readonly attribute double position;
-  //readonly attribute NodeList labels;
+  readonly attribute NodeList labels;
 };

components/script/dom/webidls/HTMLSelectElement.webidl

@@ -36,5 +36,5 @@ interface HTMLSelectElement : HTMLElement {
   //boolean reportValidity();
   //void setCustomValidity(DOMString error);
 
-  //readonly attribute NodeList labels;
+  readonly attribute NodeList labels;
 };

components/script/dom/webidls/HTMLTextAreaElement.webidl

@@ -35,7 +35,7 @@ interface HTMLTextAreaElement : HTMLElement {
   //boolean reportValidity();
   //void setCustomValidity(DOMString error);
 
-  //readonly attribute NodeList labels;
+  readonly attribute NodeList labels;
 
   //void select();
   //         attribute unsigned long selectionStart;