Auto merge of #18863 - emilio:dom-api-dont-repeat, r=jdm

style: Share code between Gecko and Servo for DOM APIs.

<!-- Reviewable:start -->
This change is [<img src="https://reviewable.io/review_button.svg" height="34" align="absmiddle" alt="Reviewable"/>](https://reviewable.io/reviews/servo/servo/18863)
<!-- Reviewable:end -->

components/script/dom/element.rs

@@ -107,6 +107,7 @@ use style::CaseSensitivityExt;
 use style::applicable_declarations::ApplicableDeclarationBlock;
 use style::attr::{AttrValue, LengthOrPercentageOrAuto};
 use style::context::QuirksMode;
+use style::dom_apis;
 use style::element_state::*;
 use style::invalidation::element::restyle_hints::RESTYLE_SELF;
 use style::properties::{Importance, PropertyDeclaration, PropertyDeclarationBlock, parse_style_attribute};
@@ -2197,18 +2198,16 @@ impl ElementMethods for Element {
 
     // https://dom.spec.whatwg.org/#dom-element-matches
     fn Matches(&self, selectors: DOMString) -> Fallible<bool> {
-        match SelectorParser::parse_author_origin_no_namespace(&selectors) {
+        let selectors =
-            Err(_) => Err(Error::Syntax),
+            match SelectorParser::parse_author_origin_no_namespace(&selectors) {
-            Ok(selectors) => {
+                Err(_) => return Err(Error::Syntax),
-                let quirks_mode = document_from_node(self).quirks_mode();
+                Ok(selectors) => selectors,
-                let root = DomRoot::from_ref(self);
+            };
-                // FIXME(bholley): Consider an nth-index cache here.
+
-                let mut ctx = MatchingContext::new(MatchingMode::Normal, None, None,
+        let quirks_mode = document_from_node(self).quirks_mode();
-                                                   quirks_mode);
+        let element = DomRoot::from_ref(self);
-                ctx.scope_element = Some(root.opaque());
+
-                Ok(matches_selector_list(&selectors, &root, &mut ctx))
+        Ok(dom_apis::element_matches(&element, &selectors, quirks_mode))
-            }
-        }
     }
 
     // https://dom.spec.whatwg.org/#dom-element-webkitmatchesselector
@@ -2218,26 +2217,18 @@ impl ElementMethods for Element {
 
     // https://dom.spec.whatwg.org/#dom-element-closest
     fn Closest(&self, selectors: DOMString) -> Fallible<Option<DomRoot<Element>>> {
-        match SelectorParser::parse_author_origin_no_namespace(&selectors) {
+        let selectors =
-            Err(_) => Err(Error::Syntax),
+            match SelectorParser::parse_author_origin_no_namespace(&selectors) {
-            Ok(selectors) => {
+                Err(_) => return Err(Error::Syntax),
-                let self_root = DomRoot::from_ref(self);
+                Ok(selectors) => selectors,
-                let root = self.upcast::<Node>();
+            };
-                for element in root.inclusive_ancestors() {
+
-                    if let Some(element) = DomRoot::downcast::<Element>(element) {
+        let quirks_mode = document_from_node(self).quirks_mode();
-                        let quirks_mode = document_from_node(self).quirks_mode();
+        Ok(dom_apis::element_closest(
-                        // FIXME(bholley): Consider an nth-index cache here.
+            DomRoot::from_ref(self),
-                        let mut ctx = MatchingContext::new(MatchingMode::Normal, None, None,
+            &selectors,
-                                                           quirks_mode);
+            quirks_mode,
-                        ctx.scope_element = Some(self_root.opaque());
+        ))
-                        if matches_selector_list(&selectors, &element, &mut ctx) {
-                            return Ok(Some(element));
-                        }
-                    }
-                }
-                Ok(None)
-            }
-        }
     }
 
     // https://dom.spec.whatwg.org/#dom-element-insertadjacentelement

components/style/dom_apis.rs

@@ -0,0 +1,59 @@
+/* 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/. */
+
+//! Generic implementations of some DOM APIs so they can be shared between Servo
+//! and Gecko.
+
+use context::QuirksMode;
+use selectors::{Element, NthIndexCache, SelectorList};
+use selectors::matching::{self, MatchingContext, MatchingMode};
+
+/// https://dom.spec.whatwg.org/#dom-element-matches
+pub fn element_matches<E>(
+    element: &E,
+    selector_list: &SelectorList<E::Impl>,
+    quirks_mode: QuirksMode,
+) -> bool
+where
+    E: Element,
+{
+    let mut context = MatchingContext::new(
+        MatchingMode::Normal,
+        None,
+        None,
+        quirks_mode,
+    );
+    context.scope_element = Some(element.opaque());
+    matching::matches_selector_list(selector_list, element, &mut context)
+}
+
+/// https://dom.spec.whatwg.org/#dom-element-closest
+pub fn element_closest<E>(
+    element: E,
+    selector_list: &SelectorList<E::Impl>,
+    quirks_mode: QuirksMode,
+) -> Option<E>
+where
+    E: Element,
+{
+    let mut nth_index_cache = NthIndexCache::default();
+
+    let mut context = MatchingContext::new(
+        MatchingMode::Normal,
+        None,
+        Some(&mut nth_index_cache),
+        quirks_mode,
+    );
+    context.scope_element = Some(element.opaque());
+
+    let mut current = Some(element);
+    while let Some(element) = current.take() {
+        if matching::matches_selector_list(selector_list, &element, &mut context) {
+            return Some(element);
+        }
+        current = element.parent_element();
+    }
+
+    return None;
+}

components/style/lib.rs

@@ -107,6 +107,7 @@ pub mod counter_style;
 pub mod custom_properties;
 pub mod data;
 pub mod dom;
+pub mod dom_apis;
 pub mod driver;
 pub mod element_state;
 #[cfg(feature = "servo")] mod encoding_support;

ports/geckolib/glue.rs

@@ -6,7 +6,7 @@ use cssparser::{Parser, ParserInput};
 use cssparser::ToCss as ParserToCss;
 use env_logger::LogBuilder;
 use malloc_size_of::MallocSizeOfOps;
-use selectors::{self, Element, NthIndexCache};
+use selectors::Element;
 use selectors::matching::{MatchingContext, MatchingMode, matches_selector};
 use servo_arc::{Arc, ArcBorrow, RawOffsetArc};
 use std::cell::RefCell;
@@ -1526,28 +1526,13 @@ pub unsafe extern "C" fn Servo_SelectorList_Closest<'a>(
     selectors: RawServoSelectorListBorrowed,
 ) -> RawGeckoElementBorrowedOrNull<'a> {
     use std::borrow::Borrow;
-
+    use style::dom_apis;
-    let mut nth_index_cache = NthIndexCache::default();
 
     let element = GeckoElement(element);
-    let mut context = MatchingContext::new(
-        MatchingMode::Normal,
-        None,
-        Some(&mut nth_index_cache),
-        element.owner_document_quirks_mode(),
-    );
-    context.scope_element = Some(element.opaque());
-
     let selectors = ::selectors::SelectorList::from_ffi(selectors).borrow();
-    let mut current = Some(element);
-    while let Some(element) = current.take() {
-        if selectors::matching::matches_selector_list(&selectors, &element, &mut context) {
-            return Some(element.0);
-        }
-        current = element.parent_element();
-    }
 
-    return None;
+    dom_apis::element_closest(element, &selectors, element.owner_document_quirks_mode())
+        .map(|e| e.0)
 }
 
 #[no_mangle]
@@ -1556,18 +1541,15 @@ pub unsafe extern "C" fn Servo_SelectorList_Matches(
     selectors: RawServoSelectorListBorrowed,
 ) -> bool {
     use std::borrow::Borrow;
+    use style::dom_apis;
 
     let element = GeckoElement(element);
-    let mut context = MatchingContext::new(
-        MatchingMode::Normal,
-        None,
-        None,
-        element.owner_document_quirks_mode(),
-    );
-    context.scope_element = Some(element.opaque());
-
     let selectors = ::selectors::SelectorList::from_ffi(selectors).borrow();
-    selectors::matching::matches_selector_list(&selectors, &element, &mut context)
+    dom_apis::element_matches(
+        &element,
+        &selectors,
+        element.owner_document_quirks_mode(),
+    )
 }
 
 #[no_mangle]