Bug 37468 - Implement ServoStyleRule::SetSelectorText method for setting CSS rule selectorText from JS. r=xidorn

--HG--
extra : source : bd0a3fdb037c308ae7eab0be3c68d00fcb9b6056

layout/style/ServoBindingList.h

@@ -289,6 +289,9 @@ SERVO_BINDING_FUNC(Servo_StyleRule_GetSelectorCount, void,
 SERVO_BINDING_FUNC(Servo_StyleRule_SelectorMatchesElement, bool,
                    RawServoStyleRuleBorrowed, RawGeckoElementBorrowed,
                    uint32_t index, mozilla::CSSPseudoElementType pseudo_type)
+SERVO_BINDING_FUNC(Servo_StyleRule_SetSelectorText, bool,
+                   RawServoStyleSheetContentsBorrowed sheet,
+                   RawServoStyleRuleBorrowed rule, const nsAString* text)
 SERVO_BINDING_FUNC(Servo_ImportRule_GetHref, void,
                    RawServoImportRuleBorrowed rule, nsAString* result)
 SERVO_BINDING_FUNC(Servo_ImportRule_GetSheet,

layout/style/ServoStyleRule.cpp

@@ -206,9 +206,23 @@ ServoStyleRule::GetSelectorText(nsAString& aSelectorText)
 void
 ServoStyleRule::SetSelectorText(const nsAString& aSelectorText)
 {
-  // XXX We need to implement this... But Gecko doesn't have this either
-  //     so it's probably okay to leave it unimplemented currently?
-  //     See bug 37468 and mozilla::css::StyleRule::SetSelectorText.
+  if (RefPtr<StyleSheet> sheet = GetStyleSheet()) {
+    ServoStyleSheet* servoSheet = sheet->AsServo();
+    nsIDocument* doc = sheet->GetAssociatedDocument();
+
+    mozAutoDocUpdate updateBatch(doc, UPDATE_STYLE, true);
+
+    // StyleRule lives inside of the Inner, it is unsafe to call WillDirty
+    // if sheet does not already have a unique Inner.
+    sheet->AssertHasUniqueInner();
+    sheet->WillDirty();
+
+    const RawServoStyleSheetContents* contents = servoSheet->RawContents();
+    if (Servo_StyleRule_SetSelectorText(contents, mRawRule, &aSelectorText)) {
+      sheet->DidDirty();
+      sheet->RuleChanged(this);
+    }
+  }
 }
 
 uint32_t

layout/style/StyleSheet.h

@@ -14,6 +14,7 @@
 #include "mozilla/ServoUtils.h"
 #include "nsICSSLoaderObserver.h"
 #include "nsWrapperCache.h"
+#include "StyleSheetInfo.h"
 
 class nsIDocument;
 class nsINode;
@@ -149,6 +150,7 @@ public:
 
   inline bool HasUniqueInner() const;
   void EnsureUniqueInner();
+  inline void AssertHasUniqueInner() const;
 
   // Append all of this sheet's child sheets to aArray.
   void AppendAllChildSheets(nsTArray<StyleSheet*>& aArray);

layout/style/StyleSheetInlines.h

@@ -133,6 +133,12 @@ StyleSheet::HasUniqueInner() const
 {
   return mInner->mSheets.Length() == 1;
 }
+
+void
+StyleSheet::AssertHasUniqueInner() const
+{
+  MOZ_ASSERT(HasUniqueInner());
+}
 
 }
 

servo/ports/geckolib/glue.rs

@@ -6,7 +6,7 @@ use cssparser::{ParseErrorKind, Parser, ParserInput, SourceLocation};
 use cssparser::ToCss as ParserToCss;
 use env_logger::Builder;
 use malloc_size_of::MallocSizeOfOps;
-use selectors::NthIndexCache;
+use selectors::{NthIndexCache, SelectorList};
 use selectors::matching::{MatchingContext, MatchingMode, matches_selector};
 use servo_arc::{Arc, ArcBorrow, RawOffsetArc};
 use smallvec::SmallVec;
@@ -1902,6 +1902,37 @@ pub extern "C" fn Servo_StyleRule_SelectorMatchesElement(
     })
 }
 
+#[no_mangle]
+pub unsafe extern "C" fn Servo_StyleRule_SetSelectorText(
+    sheet: RawServoStyleSheetContentsBorrowed,
+    rule: RawServoStyleRuleBorrowed,
+    text: *const nsAString,
+) -> bool {
+    let value_str = (*text).to_string();
+
+    write_locked_arc(rule, |rule: &mut StyleRule| {
+        use style::selector_parser::SelectorParser;
+
+        let contents = StylesheetContents::as_arc(&sheet);
+        let namespaces = contents.namespaces.read();
+        let url_data = contents.url_data.read();
+        let parser = SelectorParser {
+            stylesheet_origin: contents.origin,
+            namespaces: &namespaces,
+            url_data: Some(&url_data),
+        };
+
+        let mut parser_input = ParserInput::new(&value_str);
+        match SelectorList::parse(&parser, &mut Parser::new(&mut parser_input)) {
+            Ok(selectors) => {
+                rule.selectors = selectors;
+                true
+            }
+            Err(_) => false,
+        }
+    })
+}
+
 #[no_mangle]
 pub unsafe extern "C" fn Servo_SelectorList_Closest(
     element: RawGeckoElementBorrowed,