/* -*- 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_SVGPOINTLIST_H__ #define MOZILLA_SVGPOINTLIST_H__ #include "nsCOMPtr.h" #include "nsDebug.h" #include "nsIContent.h" #include "nsINode.h" #include "nsIWeakReferenceUtils.h" #include "nsSVGElement.h" #include "nsTArray.h" #include "SVGPoint.h" #include <string.h> namespace mozilla { class nsISVGPoint; /** * ATTENTION! WARNING! WATCH OUT!! * * Consumers that modify objects of this type absolutely MUST keep the DOM * wrappers for those lists (if any) in sync!! That's why this class is so * locked down. * * The DOM wrapper class for this class is DOMSVGPointList. */ class SVGPointList { friend class mozilla::nsISVGPoint; friend class SVGAnimatedPointList; friend class DOMSVGPointList; friend class DOMSVGPoint; public: SVGPointList(){} ~SVGPointList(){} // Only methods that don't make/permit modification to this list are public. // Only our friend classes can access methods that may change us. /// This may return an incomplete string on OOM, but that's acceptable. void GetValueAsString(nsAString& aValue) const; bool IsEmpty() const { return mItems.IsEmpty(); } uint32_t Length() const { return mItems.Length(); } const SVGPoint& operator[](uint32_t aIndex) const { return mItems[aIndex]; } bool operator==(const SVGPointList& rhs) const { // memcmp can be faster than |mItems == rhs.mItems| return mItems.Length() == rhs.mItems.Length() && memcmp(mItems.Elements(), rhs.mItems.Elements(), mItems.Length() * sizeof(SVGPoint)) == 0; } bool SetCapacity(uint32_t aSize) { return mItems.SetCapacity(aSize, fallible); } void Compact() { mItems.Compact(); } // Access to methods that can modify objects of this type is deliberately // limited. This is to reduce the chances of someone modifying objects of // this type without taking the necessary steps to keep DOM wrappers in sync. // If you need wider access to these methods, consider adding a method to // SVGAnimatedPointList and having that class act as an intermediary so it // can take care of keeping DOM wrappers in sync. protected: /** * This may fail on OOM if the internal capacity needs to be increased, in * which case the list will be left unmodified. */ nsresult CopyFrom(const SVGPointList& rhs); SVGPoint& operator[](uint32_t aIndex) { return mItems[aIndex]; } /** * This may fail (return false) on OOM if the internal capacity is being * increased, in which case the list will be left unmodified. */ bool SetLength(uint32_t aNumberOfItems) { return mItems.SetLength(aNumberOfItems, fallible); } private: // Marking the following private only serves to show which methods are only // used by our friend classes (as opposed to our subclasses) - it doesn't // really provide additional safety. nsresult SetValueFromString(const nsAString& aValue); void Clear() { mItems.Clear(); } bool InsertItem(uint32_t aIndex, const SVGPoint &aPoint) { if (aIndex >= mItems.Length()) { aIndex = mItems.Length(); } return !!mItems.InsertElementAt(aIndex, aPoint, fallible); } void ReplaceItem(uint32_t aIndex, const SVGPoint &aPoint) { MOZ_ASSERT(aIndex < mItems.Length(), "DOM wrapper caller should have raised INDEX_SIZE_ERR"); mItems[aIndex] = aPoint; } void RemoveItem(uint32_t aIndex) { MOZ_ASSERT(aIndex < mItems.Length(), "DOM wrapper caller should have raised INDEX_SIZE_ERR"); mItems.RemoveElementAt(aIndex); } bool AppendItem(SVGPoint aPoint) { return !!mItems.AppendElement(aPoint, fallible); } protected: /* See SVGLengthList for the rationale for using FallibleTArray<SVGPoint> instead * of FallibleTArray<SVGPoint, 1>. */ FallibleTArray<SVGPoint> mItems; }; /** * This SVGPointList subclass is for SVGPointListSMILType which needs a * mutable version of SVGPointList. Instances of this class do not have * DOM wrappers that need to be kept in sync, so we can safely expose any * protected base class methods required by the SMIL code. * * This class contains a strong reference to the element that instances of * this class are being used to animate. This is because the SMIL code stores * instances of this class in nsSMILValue objects, some of which are cached. * Holding a strong reference to the element here prevents the element from * disappearing out from under the SMIL code unexpectedly. */ class SVGPointListAndInfo : public SVGPointList { public: explicit SVGPointListAndInfo(nsSVGElement *aElement = nullptr) : mElement(do_GetWeakReference(static_cast<nsINode*>(aElement))) {} void SetInfo(nsSVGElement *aElement) { mElement = do_GetWeakReference(static_cast<nsINode*>(aElement)); } nsSVGElement* Element() const { nsCOMPtr<nsIContent> e = do_QueryReferent(mElement); return static_cast<nsSVGElement*>(e.get()); } /** * Returns true if this object is an "identity" value, from the perspective * of SMIL. In other words, returns true until the initial value set up in * SVGPointListSMILType::Init() has been changed with a SetInfo() call. */ bool IsIdentity() const { if (!mElement) { MOZ_ASSERT(IsEmpty(), "target element propagation failure"); return true; } return false; } nsresult CopyFrom(const SVGPointListAndInfo& rhs) { mElement = rhs.mElement; return SVGPointList::CopyFrom(rhs); } /** * Exposed so that SVGPointList baseVals can be copied to * SVGPointListAndInfo objects. Note that callers should also call * SetElement() when using this method! */ nsresult CopyFrom(const SVGPointList& rhs) { return SVGPointList::CopyFrom(rhs); } const SVGPoint& operator[](uint32_t aIndex) const { return SVGPointList::operator[](aIndex); } SVGPoint& operator[](uint32_t aIndex) { return SVGPointList::operator[](aIndex); } bool SetLength(uint32_t aNumberOfItems) { return SVGPointList::SetLength(aNumberOfItems); } private: // We must keep a weak reference to our element because we may belong to a // cached baseVal nsSMILValue. See the comments starting at: // https://bugzilla.mozilla.org/show_bug.cgi?id=515116#c15 // See also https://bugzilla.mozilla.org/show_bug.cgi?id=653497 nsWeakPtr mElement; }; } // namespace mozilla #endif // MOZILLA_SVGPOINTLIST_H__