layout/style/nsHTMLStyleSheet.cpp

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 /*
   8  * style sheet and style rule processor representing data from presentational
   9  * HTML attributes
  10  */
  11
  12 #include "nsHTMLStyleSheet.h"
  13 #include "nsMappedAttributes.h"
  14 #include "nsGkAtoms.h"
  15 #include "nsPresContext.h"
  16 #include "mozilla/EventStates.h"
  17 #include "mozilla/PresShell.h"
  18 #include "mozilla/dom/Document.h"
  19 #include "mozilla/dom/DocumentInlines.h"
  20 #include "nsStyleConsts.h"
  21 #include "nsError.h"
  22 #include "mozilla/MemoryReporting.h"
  23 #include "mozilla/dom/Element.h"
  24 #include "nsHashKeys.h"
  25 #include "mozilla/OperatorNewExtensions.h"
  26 #include "mozilla/RestyleManager.h"
  27 #include "mozilla/ServoBindings.h"
  28 #include "mozilla/ServoStyleSet.h"
  29
  30 using namespace mozilla;
  31 using namespace mozilla::dom;
  32
  33 // -----------------------------------------------------------
  34
  35 struct MappedAttrTableEntry : public PLDHashEntryHdr {
  36   nsMappedAttributes* mAttributes;
  37 };
  38
  39 static PLDHashNumber MappedAttrTable_HashKey(const void* key) {
  40   nsMappedAttributes* attributes =
  41       static_cast<nsMappedAttributes*>(const_cast<void*>(key));
  42
  43   return attributes->HashValue();
  44 }
  45
  46 static void MappedAttrTable_ClearEntry(PLDHashTable* table,
  47                                        PLDHashEntryHdr* hdr) {
  48   MappedAttrTableEntry* entry = static_cast<MappedAttrTableEntry*>(hdr);
  49
  50   entry->mAttributes->DropStyleSheetReference();
  51   memset(entry, 0, sizeof(MappedAttrTableEntry));
  52 }
  53
  54 static bool MappedAttrTable_MatchEntry(const PLDHashEntryHdr* hdr,
  55                                        const void* key) {
  56   nsMappedAttributes* attributes =
  57       static_cast<nsMappedAttributes*>(const_cast<void*>(key));
  58   const MappedAttrTableEntry* entry =
  59       static_cast<const MappedAttrTableEntry*>(hdr);
  60
  61   return attributes->Equals(entry->mAttributes);
  62 }
  63
  64 static const PLDHashTableOps MappedAttrTable_Ops = {
  65     MappedAttrTable_HashKey, MappedAttrTable_MatchEntry,
  66     PLDHashTable::MoveEntryStub, MappedAttrTable_ClearEntry, nullptr};
  67
  68 // -----------------------------------------------------------
  69
  70 // -----------------------------------------------------------
  71
  72 nsHTMLStyleSheet::nsHTMLStyleSheet(Document* aDocument)
  73     : mDocument(aDocument),
  74       mMappedAttrTable(&MappedAttrTable_Ops, sizeof(MappedAttrTableEntry)),
  75       mMappedAttrsDirty(false) {
  76   MOZ_ASSERT(aDocument);
  77 }
  78
  79 void nsHTMLStyleSheet::SetOwningDocument(Document* aDocument) {
  80   mDocument = aDocument;  // not refcounted
  81 }
  82
  83 void nsHTMLStyleSheet::Reset() {
  84   mServoUnvisitedLinkDecl = nullptr;
  85   mServoVisitedLinkDecl = nullptr;
  86   mServoActiveLinkDecl = nullptr;
  87
  88   mMappedAttrTable.Clear();
  89   mMappedAttrsDirty = false;
  90 }
  91
  92 nsresult nsHTMLStyleSheet::ImplLinkColorSetter(
  93     RefPtr<RawServoDeclarationBlock>& aDecl, nscolor aColor) {
  94   if (!mDocument || !mDocument->GetPresShell()) {
  95     return NS_OK;
  96   }
  97
  98   MOZ_ASSERT(!ServoStyleSet::IsInServoTraversal());
  99   aDecl = Servo_DeclarationBlock_CreateEmpty().Consume();
 100   Servo_DeclarationBlock_SetColorValue(aDecl.get(), eCSSProperty_color, aColor);
 101
 102   // Now make sure we restyle any links that might need it.  This
 103   // shouldn't happen often, so just rebuilding everything is ok.
 104   if (Element* root = mDocument->GetRootElement()) {
 105     RestyleManager* rm = mDocument->GetPresContext()->RestyleManager();
 106     rm->PostRestyleEvent(root, RestyleHint::RestyleSubtree(), nsChangeHint(0));
 107   }
 108   return NS_OK;
 109 }
 110
 111 nsresult nsHTMLStyleSheet::SetLinkColor(nscolor aColor) {
 112   return ImplLinkColorSetter(mServoUnvisitedLinkDecl, aColor);
 113 }
 114
 115 nsresult nsHTMLStyleSheet::SetActiveLinkColor(nscolor aColor) {
 116   return ImplLinkColorSetter(mServoActiveLinkDecl, aColor);
 117 }
 118
 119 nsresult nsHTMLStyleSheet::SetVisitedLinkColor(nscolor aColor) {
 120   return ImplLinkColorSetter(mServoVisitedLinkDecl, aColor);
 121 }
 122
 123 already_AddRefed<nsMappedAttributes> nsHTMLStyleSheet::UniqueMappedAttributes(
 124     nsMappedAttributes* aMapped) {
 125   mMappedAttrsDirty = true;
 126   auto entry = static_cast<MappedAttrTableEntry*>(
 127       mMappedAttrTable.Add(aMapped, fallible));
 128   if (!entry) return nullptr;
 129   if (!entry->mAttributes) {
 130     // We added a new entry to the hashtable, so we have a new unique set.
 131     entry->mAttributes = aMapped;
 132   }
 133   RefPtr<nsMappedAttributes> ret = entry->mAttributes;
 134   return ret.forget();
 135 }
 136
 137 void nsHTMLStyleSheet::DropMappedAttributes(nsMappedAttributes* aMapped) {
 138   NS_ENSURE_TRUE_VOID(aMapped);
 139 #ifdef DEBUG
 140   uint32_t entryCount = mMappedAttrTable.EntryCount() - 1;
 141 #endif
 142
 143   mMappedAttrTable.Remove(aMapped);
 144
 145   NS_ASSERTION(entryCount == mMappedAttrTable.EntryCount(), "not removed");
 146 }
 147
 148 void nsHTMLStyleSheet::CalculateMappedServoDeclarations() {
 149   for (auto iter = mMappedAttrTable.Iter(); !iter.Done(); iter.Next()) {
 150     MappedAttrTableEntry* attr = static_cast<MappedAttrTableEntry*>(iter.Get());
 151     if (attr->mAttributes->GetServoStyle()) {
 152       // Only handle cases which haven't been filled in already
 153       continue;
 154     }
 155     attr->mAttributes->LazilyResolveServoDeclaration(mDocument);
 156   }
 157 }
 158
 159 size_t nsHTMLStyleSheet::DOMSizeOfIncludingThis(
 160     MallocSizeOf aMallocSizeOf) const {
 161   size_t n = aMallocSizeOf(this);
 162
 163   n += mMappedAttrTable.ShallowSizeOfExcludingThis(aMallocSizeOf);
 164   for (auto iter = mMappedAttrTable.ConstIter(); !iter.Done(); iter.Next()) {
 165     auto entry = static_cast<MappedAttrTableEntry*>(iter.Get());
 166     n += entry->mAttributes->SizeOfIncludingThis(aMallocSizeOf);
 167   }
 168
 169   // Measurement of the following members may be added later if DMD finds it is
 170   // worthwhile:
 171   // - mURL
 172   // - mLinkRule
 173   // - mVisitedRule
 174   // - mActiveRule
 175   // - mTableQuirkColorRule
 176   // - mTableTHRule
 177   // - mLangRuleTable
 178   //
 179   // The following members are not measured:
 180   // - mDocument, because it's non-owning
 181
 182   return n;
 183 }