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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
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef DOM_SVG_DOMSVGPOINTLIST_H_
+#define DOM_SVG_DOMSVGPOINTLIST_H_
+
+#include "mozAutoDocUpdate.h"
+#include "nsCycleCollectionParticipant.h"
+#include "nsDebug.h"
+#include "nsTArray.h"
+#include "SVGPointList.h" // IWYU pragma: keep
+#include "mozilla/Attributes.h"
+#include "mozilla/RefPtr.h"
+
+// {61812ad1-c078-4cd1-87e6-bc1c1b8d7284}
+#define MOZILLA_DOMSVGPOINTLIST_IID \
+ { \
+ 0x61812ad1, 0xc078, 0x4cd1, { \
+ 0x87, 0xe6, 0xbc, 0x1c, 0x1b, 0x8d, 0x72, 0x84 \
+ } \
+ }
+
+namespace mozilla {
+
+class ErrorResult;
+class SVGAnimatedPointList;
+
+namespace dom {
+
+class DOMSVGPoint;
+class SVGElement;
+
+//----------------------------------------------------------------------
+// Helper class: AutoChangePointListNotifier
+// Stack-based helper class to pair calls to WillChangePointList and
+// DidChangePointList. Used by DOMSVGPoint and DOMSVGPointList.
+template <class T>
+class MOZ_RAII AutoChangePointListNotifier {
+ public:
+ explicit AutoChangePointListNotifier(T* aValue) : mValue(aValue) {
+ MOZ_ASSERT(mValue, "Expecting non-null value");
+ if (mValue->IsInList()) {
+ mUpdateBatch.emplace(mValue->Element()->GetComposedDoc(), true);
+ mEmptyOrOldValue =
+ mValue->Element()->WillChangePointList(mUpdateBatch.ref());
+ }
+ }
+
+ ~AutoChangePointListNotifier() {
+ if (mValue->IsInList()) {
+ mValue->Element()->DidChangePointList(mEmptyOrOldValue,
+ mUpdateBatch.ref());
+ if (mValue->AttrIsAnimating()) {
+ mValue->Element()->AnimationNeedsResample();
+ }
+ }
+ }
+
+ private:
+ Maybe<mozAutoDocUpdate> mUpdateBatch;
+ T* const mValue;
+ nsAttrValue mEmptyOrOldValue;
+};
+
+/**
+ * Class DOMSVGPointList
+ *
+ * This class is used to create the DOM tearoff objects that wrap internal
+ * SVGPointList objects.
+ *
+ * See the architecture comment in DOMSVGAnimatedLengthList.h first (that's
+ * LENGTH list), then continue reading the remainder of this comment.
+ *
+ * The architecture of this class is very similar to that of DOMSVGLengthList
+ * except that, since there is no nsIDOMSVGAnimatedPointList interface
+ * in SVG, we have no parent DOMSVGAnimatedPointList (unlike DOMSVGLengthList
+ * which has a parent DOMSVGAnimatedLengthList class). (There is an
+ * SVGAnimatedPoints interface, but that is quite different to
+ * DOMSVGAnimatedLengthList, since it is inherited by elements rather than
+ * elements having members of that type.) As a consequence, much of the logic
+ * that would otherwise be in DOMSVGAnimatedPointList (and is in
+ * DOMSVGAnimatedLengthList) is contained in this class.
+ *
+ * This class is strongly intertwined with DOMSVGPoint. Our DOMSVGPoint
+ * items are friends of us and responsible for nulling out our pointers to
+ * them when they die.
+ *
+ * Our DOM items are created lazily on demand as and when script requests them.
+ */
+class DOMSVGPointList final : public nsISupports, public nsWrapperCache {
+ template <class T>
+ friend class AutoChangePointListNotifier;
+ friend class DOMSVGPoint;
+
+ public:
+ NS_DECLARE_STATIC_IID_ACCESSOR(MOZILLA_DOMSVGPOINTLIST_IID)
+ NS_DECL_CYCLE_COLLECTING_ISUPPORTS
+ NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS(DOMSVGPointList)
+
+ JSObject* WrapObject(JSContext* cx,
+ JS::Handle<JSObject*> aGivenProto) override;
+
+ nsISupports* GetParentObject() { return static_cast<nsIContent*>(mElement); }
+
+ /**
+ * Factory method to create and return a DOMSVGPointList wrapper
+ * for a given internal SVGPointList object. The factory takes care
+ * of caching the object that it returns so that the same object can be
+ * returned for the given SVGPointList 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 SVGPointList will naturally result in a new
+ * DOMSVGPointList being returned.
+ *
+ * It's unfortunate that aList is a void* instead of a typed argument. This
+ * is because the mBaseVal and mAnimVal members of SVGAnimatedPointList are
+ * of different types - a plain SVGPointList, and a SVGPointList*. We
+ * use the addresses of these members as the key for the hash table, and
+ * clearly SVGPointList* and a SVGPointList** are not the same type.
+ */
+ static already_AddRefed<DOMSVGPointList> GetDOMWrapper(
+ void* aList, dom::SVGElement* aElement, bool aIsAnimValList);
+
+ /**
+ * This method returns the DOMSVGPointList wrapper for an internal
+ * SVGPointList object if it currently has a wrapper. If it does
+ * not, then nullptr is returned.
+ */
+ static DOMSVGPointList* GetDOMWrapperIfExists(void* aList);
+
+ /**
+ * 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();
+ }
+
+ /**
+ * WATCH OUT! If you add code to call this on a baseVal wrapper, then you
+ * must also call it on the animVal wrapper too if necessary!! See other
+ * callers!
+ *
+ * Called by internal code to notify us when we need to sync the length of
+ * this DOM list with its internal list. This is called immediately prior to
+ * the length of the internal list being changed so that any DOM list items
+ * that need to be removed from the DOM list can first copy 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 InternalListWillChangeTo(const SVGPointList& aNewValue);
+
+ /*
+ * We need this so that templates that work on lists and elements can check
+ * ownership where elements may be not be in a list.
+ */
+ bool IsInList() const { return true; }
+
+ /**
+ * Returns true if our attribute is animating (in which case our animVal is
+ * not simply a mirror of our baseVal).
+ */
+ bool AttrIsAnimating() const;
+
+ /**
+ * Returns true if there is an animated list mirroring the base list.
+ */
+ bool AnimListMirrorsBaseList() const;
+
+ uint32_t NumberOfItems() const {
+ if (IsAnimValList()) {
+ Element()->FlushAnimations();
+ }
+ return LengthNoFlush();
+ }
+ void Clear(ErrorResult& aError);
+ already_AddRefed<DOMSVGPoint> Initialize(DOMSVGPoint& aNewItem,
+ ErrorResult& aError);
+ already_AddRefed<DOMSVGPoint> GetItem(uint32_t index, ErrorResult& error);
+ already_AddRefed<DOMSVGPoint> IndexedGetter(uint32_t index, bool& found,
+ ErrorResult& error);
+ already_AddRefed<DOMSVGPoint> InsertItemBefore(DOMSVGPoint& aNewItem,
+ uint32_t aIndex,
+ ErrorResult& aError);
+ already_AddRefed<DOMSVGPoint> ReplaceItem(DOMSVGPoint& aNewItem,
+ uint32_t aIndex,
+ ErrorResult& aError);
+ already_AddRefed<DOMSVGPoint> RemoveItem(uint32_t aIndex,
+ ErrorResult& aError);
+ already_AddRefed<DOMSVGPoint> AppendItem(DOMSVGPoint& aNewItem,
+ ErrorResult& aError) {
+ return InsertItemBefore(aNewItem, LengthNoFlush(), aError);
+ }
+ uint32_t Length() const { return NumberOfItems(); }
+
+ private:
+ /**
+ * Only our static GetDOMWrapper() factory method may create objects of our
+ * type.
+ */
+ DOMSVGPointList(dom::SVGElement* aElement, bool aIsAnimValList)
+ : mElement(aElement), mIsAnimValList(aIsAnimValList) {
+ InternalListWillChangeTo(InternalList()); // Sync mItems
+ }
+
+ ~DOMSVGPointList();
+
+ dom::SVGElement* Element() const { return mElement.get(); }
+
+ /// Used to determine if this list is the baseVal or animVal list.
+ bool IsAnimValList() const { return mIsAnimValList; }
+
+ /**
+ * Get a reference to this object's corresponding internal SVGPointList.
+ *
+ * To simplify the code we just have this one method for obtaining both
+ * base val and anim val internal lists. This means that anim val lists don't
+ * get const protection, but our setter methods guard against changing
+ * anim val lists.
+ */
+ SVGPointList& InternalList() const;
+
+ SVGAnimatedPointList& InternalAList() const;
+
+ /// Returns the DOMSVGPoint at aIndex, creating it if necessary.
+ already_AddRefed<DOMSVGPoint> GetItemAt(uint32_t aIndex);
+
+ void MaybeInsertNullInAnimValListAt(uint32_t aIndex);
+ void MaybeRemoveItemFromAnimValListAt(uint32_t aIndex);
+
+ void RemoveFromTearoffTable();
+
+ // Weak refs to our DOMSVGPoint items. The items are friends and take care
+ // of clearing our pointer to them when they die.
+ FallibleTArray<DOMSVGPoint*> mItems;
+
+ // Strong ref to our element to keep it alive. We hold this not only for
+ // ourself, but also for our DOMSVGPoint items too.
+ RefPtr<dom::SVGElement> mElement;
+
+ bool mIsAnimValList;
+};
+
+NS_DEFINE_STATIC_IID_ACCESSOR(DOMSVGPointList, MOZILLA_DOMSVGPOINTLIST_IID)
+
+} // namespace dom
+} // namespace mozilla
+
+#endif // DOM_SVG_DOMSVGPOINTLIST_H_