dom/animation/AnimationTarget.h

   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 #ifndef mozilla_AnimationTarget_h
   8 #define mozilla_AnimationTarget_h
   9
  10 #include "mozilla/Attributes.h"     // For MOZ_NON_OWNING_REF
  11 #include "mozilla/HashFunctions.h"  // For HashNumber, AddToHash
  12 #include "mozilla/HashTable.h"      // For DefaultHasher, PointerHasher
  13 #include "mozilla/Maybe.h"
  14 #include "mozilla/RefPtr.h"
  15 #include "nsCSSPseudoElements.h"
  16
  17 namespace mozilla {
  18
  19 namespace dom {
  20 class Element;
  21 }  // namespace dom
  22
  23 struct OwningAnimationTarget {
  24   OwningAnimationTarget() = default;
  25
  26   OwningAnimationTarget(dom::Element* aElement, PseudoStyleType aType)
  27       : mElement(aElement), mPseudoType(aType) {}
  28
  29   explicit OwningAnimationTarget(dom::Element* aElement) : mElement(aElement) {}
  30
  31   bool operator==(const OwningAnimationTarget& aOther) const {
  32     return mElement == aOther.mElement && mPseudoType == aOther.mPseudoType;
  33   }
  34
  35   explicit operator bool() const { return !!mElement; }
  36
  37   // mElement represents the parent element of a pseudo-element, not the
  38   // generated content element.
  39   RefPtr<dom::Element> mElement;
  40   PseudoStyleType mPseudoType = PseudoStyleType::NotPseudo;
  41 };
  42
  43 struct NonOwningAnimationTarget {
  44   NonOwningAnimationTarget() = default;
  45
  46   NonOwningAnimationTarget(dom::Element* aElement, PseudoStyleType aType)
  47       : mElement(aElement), mPseudoType(aType) {}
  48
  49   explicit NonOwningAnimationTarget(const OwningAnimationTarget& aOther)
  50       : mElement(aOther.mElement), mPseudoType(aOther.mPseudoType) {}
  51
  52   bool operator==(const NonOwningAnimationTarget& aOther) const {
  53     return mElement == aOther.mElement && mPseudoType == aOther.mPseudoType;
  54   }
  55
  56   NonOwningAnimationTarget& operator=(const OwningAnimationTarget& aOther) {
  57     mElement = aOther.mElement;
  58     mPseudoType = aOther.mPseudoType;
  59     return *this;
  60   }
  61
  62   explicit operator bool() const { return !!mElement; }
  63
  64   // mElement represents the parent element of a pseudo-element, not the
  65   // generated content element.
  66   dom::Element* MOZ_NON_OWNING_REF mElement = nullptr;
  67   PseudoStyleType mPseudoType = PseudoStyleType::NotPseudo;
  68 };
  69
  70 // Helper functions for cycle-collecting Maybe<OwningAnimationTarget>
  71 inline void ImplCycleCollectionTraverse(
  72     nsCycleCollectionTraversalCallback& aCallback,
  73     Maybe<OwningAnimationTarget>& aTarget, const char* aName,
  74     uint32_t aFlags = 0) {
  75   if (aTarget) {
  76     ImplCycleCollectionTraverse(aCallback, aTarget->mElement, aName, aFlags);
  77   }
  78 }
  79
  80 inline void ImplCycleCollectionUnlink(Maybe<OwningAnimationTarget>& aTarget) {
  81   if (aTarget) {
  82     ImplCycleCollectionUnlink(aTarget->mElement);
  83   }
  84 }
  85
  86 // A DefaultHasher specialization for OwningAnimationTarget.
  87 template <>
  88 struct DefaultHasher<OwningAnimationTarget> {
  89   using Key = OwningAnimationTarget;
  90   using Lookup = OwningAnimationTarget;
  91   using PtrHasher = PointerHasher<dom::Element*>;
  92
  93   static HashNumber hash(const Lookup& aLookup) {
  94     return AddToHash(PtrHasher::hash(aLookup.mElement.get()),
  95                      static_cast<uint8_t>(aLookup.mPseudoType));
  96   }
  97
  98   static bool match(const Key& aKey, const Lookup& aLookup) {
  99     return PtrHasher::match(aKey.mElement.get(), aLookup.mElement.get()) &&
 100            aKey.mPseudoType == aLookup.mPseudoType;
 101   }
 102
 103   static void rekey(Key& aKey, Key&& aNewKey) { aKey = std::move(aNewKey); }
 104 };
 105
 106 }  // namespace mozilla
 107
 108 #endif  // mozilla_AnimationTarget_h