/* -*- 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/. */ #ifndef MOZILLA_DOMSVGANIMATEDNUMBERLIST_H__ #define MOZILLA_DOMSVGANIMATEDNUMBERLIST_H__ #include "nsCOMPtr.h" #include "nsCycleCollectionParticipant.h" #include "nsSVGElement.h" #include "nsWrapperCache.h" #include "mozilla/Attributes.h" namespace mozilla { class DOMSVGNumberList; class SVGAnimatedNumberList; class SVGNumberList; /** * Class DOMSVGAnimatedNumberList * * This class is used to create the DOM tearoff objects that wrap internal * SVGAnimatedNumberList objects. * * See the architecture comment in DOMSVGAnimatedLengthList.h (that's * LENGTH list). The comment for that class largly applies to this one too * and will go a long way to helping you understand the architecture here. * * This class is strongly intertwined with DOMSVGNumberList and DOMSVGNumber. * Our DOMSVGNumberList base and anim vals are friends and take care of nulling * out our pointers to them when they die (making our pointers to them true * weak refs). */ class DOMSVGAnimatedNumberList final : public nsISupports, public nsWrapperCache { friend class DOMSVGNumberList; public: NS_DECL_CYCLE_COLLECTING_ISUPPORTS NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS(DOMSVGAnimatedNumberList) /** * Factory method to create and return a DOMSVGAnimatedNumberList wrapper * for a given internal SVGAnimatedNumberList object. The factory takes care * of caching the object that it returns so that the same object can be * returned for the given SVGAnimatedNumberList each time it is requested. * The cached object is only removed from the cache when it is destroyed due * to there being no more references to it or to any of its descendant * objects. If that happens, any subsequent call requesting the DOM wrapper * for the SVGAnimatedNumberList will naturally result in a new * DOMSVGAnimatedNumberList being returned. */ static already_AddRefed<DOMSVGAnimatedNumberList> GetDOMWrapper(SVGAnimatedNumberList *aList, nsSVGElement *aElement, uint8_t aAttrEnum); /** * This method returns the DOMSVGAnimatedNumberList wrapper for an internal * SVGAnimatedNumberList object if it currently has a wrapper. If it does * not, then nullptr is returned. */ static DOMSVGAnimatedNumberList* GetDOMWrapperIfExists(SVGAnimatedNumberList *aList); /** * Called by internal code to notify us when we need to sync the length of * our baseVal DOM list with its internal list. This is called just prior to * the length of the internal baseVal list being changed so that any DOM list * items that need to be removed from the DOM list can first get their values * from their internal counterpart. * * The only time this method could fail is on OOM when trying to increase the * length of the DOM list. If that happens then this method simply clears the * list and returns. Callers just proceed as normal, and we simply accept * that the DOM list will be empty (until successfully set to a new value). */ void InternalBaseValListWillChangeTo(const SVGNumberList& aNewValue); void InternalAnimValListWillChangeTo(const SVGNumberList& aNewValue); /** * Returns true if our attribute is animating (in which case our animVal is * not simply a mirror of our baseVal). */ bool IsAnimating() const; // WebIDL nsSVGElement* GetParentObject() const { return mElement; } virtual JSObject* WrapObject(JSContext* aCx, JS::Handle<JSObject*> aGivenProto) override; // These aren't weak refs because mBaseVal and mAnimVal are weak already_AddRefed<DOMSVGNumberList> BaseVal(); already_AddRefed<DOMSVGNumberList> AnimVal(); private: /** * Only our static GetDOMWrapper() factory method may create objects of our * type. */ DOMSVGAnimatedNumberList(nsSVGElement *aElement, uint8_t aAttrEnum) : mBaseVal(nullptr) , mAnimVal(nullptr) , mElement(aElement) , mAttrEnum(aAttrEnum) { } ~DOMSVGAnimatedNumberList(); /// Get a reference to this DOM wrapper object's internal counterpart. SVGAnimatedNumberList& InternalAList(); const SVGAnimatedNumberList& InternalAList() const; // Weak refs to our DOMSVGNumberList baseVal/animVal objects. These objects // are friends and take care of clearing these pointers when they die, making // these true weak references. DOMSVGNumberList *mBaseVal; DOMSVGNumberList *mAnimVal; // Strong ref to our element to keep it alive. We hold this not only for // ourself, but also for our base/animVal and all of their items. RefPtr<nsSVGElement> mElement; uint8_t mAttrEnum; }; } // namespace mozilla #endif // MOZILLA_DOMSVGANIMATEDNUMBERLIST_H__