dom/animation/CSSPseudoElement.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 #include "mozilla/dom/CSSPseudoElement.h"
   8 #include "mozilla/dom/CSSPseudoElementBinding.h"
   9 #include "mozilla/dom/Element.h"
  10 #include "mozilla/dom/KeyframeEffectBinding.h"
  11 #include "mozilla/AnimationComparator.h"
  12
  13 namespace mozilla::dom {
  14
  15 NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE(CSSPseudoElement, mOriginatingElement)
  16
  17 CSSPseudoElement::CSSPseudoElement(dom::Element* aElement,
  18                                    PseudoStyleType aType)
  19     : mOriginatingElement(aElement), mPseudoType(aType) {
  20   MOZ_ASSERT(aElement);
  21   MOZ_ASSERT(AnimationUtils::IsSupportedPseudoForAnimations(aType),
  22              "Unexpected Pseudo Type");
  23 }
  24
  25 CSSPseudoElement::~CSSPseudoElement() {
  26   // Element might have been unlinked already, so we have to do null check.
  27   if (mOriginatingElement) {
  28     mOriginatingElement->RemoveProperty(
  29         GetCSSPseudoElementPropertyAtom(mPseudoType));
  30   }
  31 }
  32
  33 ParentObject CSSPseudoElement::GetParentObject() const {
  34   return mOriginatingElement->GetParentObject();
  35 }
  36
  37 JSObject* CSSPseudoElement::WrapObject(JSContext* aCx,
  38                                        JS::Handle<JSObject*> aGivenProto) {
  39   return CSSPseudoElement_Binding::Wrap(aCx, this, aGivenProto);
  40 }
  41
  42 /* static */
  43 already_AddRefed<CSSPseudoElement> CSSPseudoElement::GetCSSPseudoElement(
  44     dom::Element* aElement, PseudoStyleType aType) {
  45   if (!aElement) {
  46     return nullptr;
  47   }
  48
  49   nsAtom* propName = CSSPseudoElement::GetCSSPseudoElementPropertyAtom(aType);
  50   RefPtr<CSSPseudoElement> pseudo =
  51       static_cast<CSSPseudoElement*>(aElement->GetProperty(propName));
  52   if (pseudo) {
  53     return pseudo.forget();
  54   }
  55
  56   // CSSPseudoElement is a purely external interface created on-demand, and
  57   // when all references from script to the pseudo are dropped, we can drop the
  58   // CSSPseudoElement object, so use a non-owning reference from Element to
  59   // CSSPseudoElement.
  60   pseudo = new CSSPseudoElement(aElement, aType);
  61   nsresult rv = aElement->SetProperty(propName, pseudo, nullptr, true);
  62   if (NS_FAILED(rv)) {
  63     NS_WARNING("SetProperty failed");
  64     return nullptr;
  65   }
  66   return pseudo.forget();
  67 }
  68
  69 /* static */
  70 nsAtom* CSSPseudoElement::GetCSSPseudoElementPropertyAtom(
  71     PseudoStyleType aType) {
  72   switch (aType) {
  73     case PseudoStyleType::before:
  74       return nsGkAtoms::cssPseudoElementBeforeProperty;
  75
  76     case PseudoStyleType::after:
  77       return nsGkAtoms::cssPseudoElementAfterProperty;
  78
  79     case PseudoStyleType::marker:
  80       return nsGkAtoms::cssPseudoElementMarkerProperty;
  81
  82     default:
  83       MOZ_ASSERT_UNREACHABLE(
  84           "Should not try to get CSSPseudoElement "
  85           "other than ::before, ::after or ::marker");
  86       return nullptr;
  87   }
  88 }
  89
  90 }  // namespace mozilla::dom