1 files changed, 147 insertions, 0 deletions
diff --git a/layout/style/GroupRule.cpp b/layout/style/GroupRule.cpp
new file mode 100644
index 0000000000..ff3cd11f8c
--- /dev/null
+++ b/layout/style/GroupRule.cpp
@@ -0,0 +1,147 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* 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/. */
+
+/*
+ * internal interface representing CSS style rules that contain other
+ * rules, such as @media rules
+ */
+
+#include "mozilla/css/GroupRule.h"
+
+#include "mozilla/dom/CSSRuleList.h"
+
+#include "nsPrintfCString.h"
+
+using namespace mozilla::dom;
+
+namespace mozilla::css {
+
+GroupRule::GroupRule(StyleSheet* aSheet, Rule* aParentRule,
+                     uint32_t aLineNumber, uint32_t aColumnNumber)
+    : Rule(aSheet, aParentRule, aLineNumber, aColumnNumber) {}
+
+GroupRule::~GroupRule() {
+  MOZ_ASSERT(!mSheet, "SetStyleSheet should have been called");
+  if (mRuleList) {
+    mRuleList->DropReferences();
+  }
+}
+
+NS_IMPL_ADDREF_INHERITED(GroupRule, Rule)
+NS_IMPL_RELEASE_INHERITED(GroupRule, Rule)
+
+NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(GroupRule)
+NS_INTERFACE_MAP_END_INHERITING(Rule)
+
+bool GroupRule::IsCCLeaf() const {
+  if (!Rule::IsCCLeaf()) {
+    return false;
+  }
+  return !mRuleList;
+}
+
+ServoCSSRuleList* GroupRule::CssRules() {
+  if (!mRuleList) {
+    // Lazily create the rule list since most style rules won't have child
+    // rules.
+    mRuleList =
+        new ServoCSSRuleList(GetOrCreateRawRules(), GetStyleSheet(), this);
+  }
+  return mRuleList;
+}
+
+NS_IMPL_CYCLE_COLLECTION_CLASS(GroupRule)
+
+NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN_INHERITED(GroupRule, Rule)
+  if (tmp->mRuleList) {
+    // If tmp has a style sheet (which can happen if it gets unlinked
+    // earlier than its owning style sheet), then we need to null out the
+    // style sheet pointer on descendants now, before we clear mRuleList.
+    tmp->mRuleList->DropReferences();
+    tmp->mRuleList = nullptr;
+  }
+NS_IMPL_CYCLE_COLLECTION_UNLINK_END
+
+NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN_INHERITED(GroupRule, Rule)
+  ImplCycleCollectionTraverse(cb, tmp->mRuleList, "mRuleList");
+NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
+
+#ifdef DEBUG
+void GroupRule::List(FILE* out, int32_t aIndent) const {
+  // TODO list something reasonable?
+}
+#endif
+
+/* virtual */
+void GroupRule::DropSheetReference() {
+  if (mRuleList) {
+    mRuleList->DropSheetReference();
+  }
+  Rule::DropSheetReference();
+}
+
+uint32_t GroupRule::InsertRule(const nsACString& aRule, uint32_t aIndex,
+                               ErrorResult& aRv) {
+  if (IsReadOnly()) {
+    return 0;
+  }
+
+  StyleSheet* sheet = GetStyleSheet();
+  if (NS_WARN_IF(!sheet)) {
+    aRv.Throw(NS_ERROR_FAILURE);
+    return 0;
+  }
+
+  uint32_t count = StyleRuleCount();
+  if (aIndex > count) {
+    aRv.ThrowIndexSizeError(nsPrintfCString(
+        "Can't insert rule at index %u because rule list length is %u", aIndex,
+        count));
+    return 0;
+  }
+
+  NS_ASSERTION(count <= INT32_MAX, "Too many style rules!");
+
+  nsresult rv = sheet->InsertRuleIntoGroup(aRule, this, aIndex);
+  if (NS_FAILED(rv)) {
+    aRv.Throw(rv);
+    return 0;
+  }
+  return aIndex;
+}
+
+void GroupRule::DeleteRule(uint32_t aIndex, ErrorResult& aRv) {
+  if (IsReadOnly()) {
+    return;
+  }
+
+  StyleSheet* sheet = GetStyleSheet();
+  if (NS_WARN_IF(!sheet)) {
+    aRv.Throw(NS_ERROR_FAILURE);
+    return;
+  }
+
+  uint32_t count = StyleRuleCount();
+  if (aIndex >= count) {
+    aRv.ThrowIndexSizeError(nsPrintfCString(
+        "Index %u is too large for list of length %u", aIndex, count));
+    return;
+  }
+
+  NS_ASSERTION(count <= INT32_MAX, "Too many style rules!");
+
+  nsresult rv = sheet->DeleteRuleFromGroup(this, aIndex);
+  if (NS_FAILED(rv)) {
+    aRv.Throw(rv);
+  }
+}
+
+size_t GroupRule::SizeOfExcludingThis(MallocSizeOf aMallocSizeOf) const {
+  // TODO how to implement?
+  return 0;
+}
+
+}  // namespace mozilla::css