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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_SVGPOINTLIST_H_
+#define DOM_SVG_SVGPOINTLIST_H_
+
+#include "nsCOMPtr.h"
+#include "nsDebug.h"
+#include "nsIContent.h"
+#include "nsINode.h"
+#include "nsIWeakReferenceUtils.h"
+#include "SVGElement.h"
+#include "nsTArray.h"
+#include "SVGPoint.h"
+
+#include <string.h>
+
+namespace mozilla {
+
+namespace dom {
+class DOMSVGPoint;
+class DOMSVGPointList;
+} // namespace dom
+
+/**
+ * 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 SVGAnimatedPointList;
+ friend class dom::DOMSVGPointList;
+ friend class dom::DOMSVGPoint;
+
+ public:
+ SVGPointList() = default;
+ ~SVGPointList() = default;
+
+ // 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);
+ void SwapWith(SVGPointList& aRhs) { mItems.SwapElements(aRhs.mItems); }
+
+ 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 SMILValue 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(dom::SVGElement* aElement = nullptr)
+ : mElement(do_GetWeakReference(static_cast<nsINode*>(aElement))) {}
+
+ void SetInfo(dom::SVGElement* aElement) {
+ mElement = do_GetWeakReference(static_cast<nsINode*>(aElement));
+ }
+
+ dom::SVGElement* Element() const {
+ nsCOMPtr<nsIContent> e = do_QueryReferent(mElement);
+ return static_cast<dom::SVGElement*>(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 SMILValue. 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 // DOM_SVG_SVGPOINTLIST_H_