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Diffstat (limited to 'dom/svg/DOMSVGAnimatedNumberList.h')
-rw-r--r-- | dom/svg/DOMSVGAnimatedNumberList.h | 133 |
1 files changed, 133 insertions, 0 deletions
diff --git a/dom/svg/DOMSVGAnimatedNumberList.h b/dom/svg/DOMSVGAnimatedNumberList.h new file mode 100644 index 000000000..b26076634 --- /dev/null +++ b/dom/svg/DOMSVGAnimatedNumberList.h @@ -0,0 +1,133 @@ +/* -*- 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__ |