/* -*- 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_DOMSVGLENGTHLIST_H__ #define MOZILLA_DOMSVGLENGTHLIST_H__ #include "DOMSVGAnimatedLengthList.h" #include "nsCycleCollectionParticipant.h" #include "nsDebug.h" #include "nsTArray.h" #include "SVGLengthList.h" #include "mozilla/Attributes.h" #include "mozilla/ErrorResult.h" class nsSVGElement; namespace mozilla { class DOMSVGLength; /** * Class DOMSVGLengthList * * This class is used to create the DOM tearoff objects that wrap internal * SVGLengthList objects. * * See the architecture comment in DOMSVGAnimatedLengthList.h. * * This class is strongly intertwined with DOMSVGAnimatedLengthList and * DOMSVGLength. We are a friend of DOMSVGAnimatedLengthList, and are * responsible for nulling out our DOMSVGAnimatedLengthList's pointer to us * when we die, essentially making its pointer to us a weak pointer. Similarly, * our DOMSVGLength items are friends of us and responsible for nulling out our * pointers to them. * * Our DOM items are created lazily on demand as and when script requests them. */ class DOMSVGLengthList final : public nsISupports, public nsWrapperCache { friend class AutoChangeLengthListNotifier; friend class DOMSVGLength; ~DOMSVGLengthList() { // Our mAList's weak ref to us must be nulled out when we die. If GC has // unlinked us using the cycle collector code, then that has already // happened, and mAList is null. if (mAList) { ( IsAnimValList() ? mAList->mAnimVal : mAList->mBaseVal ) = nullptr; } } public: NS_DECL_CYCLE_COLLECTING_ISUPPORTS NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS(DOMSVGLengthList) DOMSVGLengthList(DOMSVGAnimatedLengthList *aAList, const SVGLengthList &aInternalList) : mAList(aAList) { // aInternalList must be passed in explicitly because we can't use // InternalList() here. (Because it depends on IsAnimValList, which depends // on this object having been assigned to aAList's mBaseVal or mAnimVal, // which hasn't happend yet.) InternalListLengthWillChange(aInternalList.Length()); // Sync mItems } virtual JSObject* WrapObject(JSContext *cx, JS::Handle<JSObject*> aGivenProto) override; nsISupports* GetParentObject() { return static_cast<nsIContent*>(Element()); } /** * This will normally be the same as InternalList().Length(), except if we've * hit OOM in which case our length will be zero. */ uint32_t LengthNoFlush() const { MOZ_ASSERT(mItems.Length() == 0 || mItems.Length() == InternalList().Length(), "DOM wrapper's list length is out of sync"); return mItems.Length(); } /// Called to notify us to syncronize our length and detach excess items. void InternalListLengthWillChange(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 { return mAList->IsAnimating(); } /** * Returns true if there is an animated list mirroring the base list. */ bool AnimListMirrorsBaseList() const { return mAList->mAnimVal && !mAList->IsAnimating(); } uint32_t NumberOfItems() const { if (IsAnimValList()) { Element()->FlushAnimations(); } return LengthNoFlush(); } void Clear(ErrorResult& aError); already_AddRefed<DOMSVGLength> Initialize(DOMSVGLength& newItem, ErrorResult& error); already_AddRefed<DOMSVGLength> GetItem(uint32_t index, ErrorResult& error); already_AddRefed<DOMSVGLength> IndexedGetter(uint32_t index, bool& found, ErrorResult& error); already_AddRefed<DOMSVGLength> InsertItemBefore(DOMSVGLength& newItem, uint32_t index, ErrorResult& error); already_AddRefed<DOMSVGLength> ReplaceItem(DOMSVGLength& newItem, uint32_t index, ErrorResult& error); already_AddRefed<DOMSVGLength> RemoveItem(uint32_t index, ErrorResult& error); already_AddRefed<DOMSVGLength> AppendItem(DOMSVGLength& newItem, ErrorResult& error) { return InsertItemBefore(newItem, LengthNoFlush(), error); } uint32_t Length() const { return NumberOfItems(); } private: nsSVGElement* Element() const { return mAList->mElement; } uint8_t AttrEnum() const { return mAList->mAttrEnum; } uint8_t Axis() const { return mAList->mAxis; } /// Used to determine if this list is the baseVal or animVal list. bool IsAnimValList() const { MOZ_ASSERT(this == mAList->mBaseVal || this == mAList->mAnimVal, "Calling IsAnimValList() too early?!"); return this == mAList->mAnimVal; } /** * Get a reference to this object's corresponding internal SVGLengthList. * * To simplify the code we just have this one method for obtaining both * baseVal and animVal internal lists. This means that animVal lists don't * get const protection, but our setter methods guard against changing * animVal lists. */ SVGLengthList& InternalList() const; /// Returns the DOMSVGLength at aIndex, creating it if necessary. already_AddRefed<DOMSVGLength> GetItemAt(uint32_t aIndex); void MaybeInsertNullInAnimValListAt(uint32_t aIndex); void MaybeRemoveItemFromAnimValListAt(uint32_t aIndex); // Weak refs to our DOMSVGLength items. The items are friends and take care // of clearing our pointer to them when they die. FallibleTArray<DOMSVGLength*> mItems; RefPtr<DOMSVGAnimatedLengthList> mAList; }; } // namespace mozilla #endif // MOZILLA_DOMSVGLENGTHLIST_H__