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Diffstat (limited to 'dom/svg/DOMSVGLengthList.h')
| -rw-r--r-- | dom/svg/DOMSVGLengthList.h | 185 |
1 files changed, 185 insertions, 0 deletions
diff --git a/dom/svg/DOMSVGLengthList.h b/dom/svg/DOMSVGLengthList.h new file mode 100644 index 000000000..842d29134 --- /dev/null +++ b/dom/svg/DOMSVGLengthList.h @@ -0,0 +1,185 @@ +/* -*- 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__ |