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/* -*- 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
#ifndef DOM_SVG_DOMSVGANIMATEDTRANSFORMLIST_H_
#define DOM_SVG_DOMSVGANIMATEDTRANSFORMLIST_H_
#include "nsCycleCollectionParticipant.h"
#include "SVGElement.h"
#include "nsWrapperCache.h"
#include "mozilla/Attributes.h"
#include "mozilla/RefPtr.h"
namespace mozilla {
class SVGAnimatedTransformList;
namespace dom {
class DOMSVGTransformList;
/**
* Class DOMSVGAnimatedTransformList
*
* This class is used to create the DOM tearoff objects that wrap internal
* SVGAnimatedTransformList 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 DOMSVGTransformList and
* DOMSVGTransform.
* Our DOMSVGTransformList 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 DOMSVGAnimatedTransformList final : public nsWrapperCache {
friend class DOMSVGTransformList;
public:
NS_INLINE_DECL_CYCLE_COLLECTING_NATIVE_REFCOUNTING(
DOMSVGAnimatedTransformList)
NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_NATIVE_CLASS(
DOMSVGAnimatedTransformList)
/**
* Factory method to create and return a DOMSVGAnimatedTransformList wrapper
* for a given internal SVGAnimatedTransformList object. The factory takes
* care of caching the object that it returns so that the same object can be
* returned for the given SVGAnimatedTransformList 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 SVGAnimatedTransformList will naturally result in a new
* DOMSVGAnimatedTransformList being returned.
*/
static already_AddRefed<DOMSVGAnimatedTransformList> GetDOMWrapper(
SVGAnimatedTransformList* aList, SVGElement* aElement);
/**
* This method returns the DOMSVGAnimatedTransformList wrapper for an internal
* SVGAnimatedTransformList object if it currently has a wrapper. If it does
* not, then nullptr is returned.
*/
static DOMSVGAnimatedTransformList* GetDOMWrapperIfExists(
SVGAnimatedTransformList* 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 InternalBaseValListWillChangeLengthTo(uint32_t aNewLength);
void InternalAnimValListWillChangeLengthTo(uint32_t aNewLength);
/**
* Returns true if our attribute is animating (in which case our animVal is
* not simply a mirror of our baseVal).
*/
bool IsAnimating() const;
// WebIDL
SVGElement* GetParentObject() const { return mElement; }
JSObject* WrapObject(JSContext* aCx,
JS::Handle<JSObject*> aGivenProto) override;
// These aren't weak refs because mBaseVal and mAnimVal are weak
already_AddRefed<DOMSVGTransformList> BaseVal();
already_AddRefed<DOMSVGTransformList> AnimVal();
private:
/**
* Only our static GetDOMWrapper() factory method may create objects of our
* type.
*/
explicit DOMSVGAnimatedTransformList(SVGElement* aElement)
: mBaseVal(nullptr), mAnimVal(nullptr), mElement(aElement) {}
~DOMSVGAnimatedTransformList();
/// Get a reference to this DOM wrapper object's internal counterpart.
SVGAnimatedTransformList& InternalAList();
const SVGAnimatedTransformList& InternalAList() const;
// Weak refs to our DOMSVGTransformList baseVal/animVal objects. These objects
// are friends and take care of clearing these pointers when they die, making
// these true weak references.
DOMSVGTransformList* mBaseVal;
DOMSVGTransformList* 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<SVGElement> mElement;
};
} // namespace dom
} // namespace mozilla
#endif // DOM_SVG_DOMSVGANIMATEDTRANSFORMLIST_H_