tor-browser

The Tor Browser
git clone https://git.dasho.dev/tor-browser.git
Log | Files | Refs | README | LICENSE

DOMSVGStringList.h (4767B)

      1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
      2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
      3 /* This Source Code Form is subject to the terms of the Mozilla Public
      4 * License, v. 2.0. If a copy of the MPL was not distributed with this
      5 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
      6 
      7 #ifndef DOM_SVG_DOMSVGSTRINGLIST_H_
      8 #define DOM_SVG_DOMSVGSTRINGLIST_H_
      9 
     10 #include "SVGElement.h"
     11 #include "mozilla/RefPtr.h"
     12 #include "nsCycleCollectionParticipant.h"
     13 
     14 namespace mozilla {
     15 
     16 class ErrorResult;
     17 class SVGStringList;
     18 
     19 namespace dom {
     20 
     21 /**
     22 * Class DOMSVGStringList
     23 *
     24 * This class is used to create the DOM tearoff objects that wrap internal
     25 * SVGPathData objects.
     26 *
     27 * See the architecture comment in DOMSVGAnimatedLengthList.h first (that's
     28 * LENGTH list), then continue reading the remainder of this comment.
     29 *
     30 * The architecture of this class is similar to that of DOMSVGLengthList
     31 * except for two important aspects:
     32 *
     33 * First, since there is no nsIDOMSVGAnimatedStringList interface in SVG, we
     34 * have no parent DOMSVGAnimatedStringList (unlike DOMSVGLengthList which has
     35 * a parent DOMSVGAnimatedLengthList class). As a consequence, much of the
     36 * logic that would otherwise be in DOMSVGAnimatedStringList (and is in
     37 * DOMSVGAnimatedLengthList) is contained in this class.
     38 *
     39 * Second, since there is no nsIDOMSVGString interface in SVG, we have no
     40 * DOMSVGString items to maintain. As far as script is concerned, objects
     41 * of this class contain a list of strings, not a list of mutable objects
     42 * like the other SVG list types. As a result, unlike the other SVG list
     43 * types, this class does not create its items lazily on demand and store
     44 * them so it can return the same objects each time. It simply returns a new
     45 * string each time any given item is requested.
     46 */
     47 class DOMSVGStringList final : public nsISupports, public nsWrapperCache {
     48  friend class AutoChangeStringListNotifier;
     49 
     50 public:
     51  NS_DECL_CYCLE_COLLECTING_ISUPPORTS
     52  NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS(DOMSVGStringList)
     53 
     54  dom::SVGElement* GetParentObject() const { return mElement; }
     55  JSObject* WrapObject(JSContext* aCx,
     56                       JS::Handle<JSObject*> aGivenProto) override;
     57 
     58  uint32_t NumberOfItems() const;
     59  uint32_t Length() const;
     60  void Clear();
     61  void Initialize(const nsAString& aNewItem, nsAString& aRetval,
     62                  ErrorResult& aRv);
     63  void GetItem(uint32_t aIndex, nsAString& aRetval, ErrorResult& aRv);
     64  void IndexedGetter(uint32_t aIndex, bool& aFound, nsAString& aRetval);
     65  void InsertItemBefore(const nsAString& aNewItem, uint32_t aIndex,
     66                        nsAString& aRetval, ErrorResult& aRv);
     67  void ReplaceItem(const nsAString& aNewItem, uint32_t aIndex,
     68                   nsAString& aRetval, ErrorResult& aRv);
     69  void RemoveItem(uint32_t aIndex, nsAString& aRetval, ErrorResult& aRv);
     70  void AppendItem(const nsAString& aNewItem, nsAString& aRetval,
     71                  ErrorResult& aRv);
     72 
     73  /**
     74   * Factory method to create and return a DOMSVGStringList wrapper
     75   * for a given internal SVGStringList object. The factory takes care
     76   * of caching the object that it returns so that the same object can be
     77   * returned for the given SVGStringList each time it is requested.
     78   * The cached object is only removed from the cache when it is destroyed due
     79   * to there being no more references to it. If that happens, any subsequent
     80   * call requesting the DOM wrapper for the SVGStringList will naturally
     81   * result in a new DOMSVGStringList being returned.
     82   */
     83  static already_AddRefed<DOMSVGStringList> GetDOMWrapper(
     84      SVGStringList* aList, dom::SVGElement* aElement,
     85      bool aIsConditionalProcessingAttribute, uint8_t aAttrEnum);
     86 
     87 private:
     88  /**
     89   * Only our static GetDOMWrapper() factory method may create objects of our
     90   * type.
     91   */
     92  DOMSVGStringList(dom::SVGElement* aElement,
     93                   bool aIsConditionalProcessingAttribute, uint8_t aAttrEnum)
     94      : mElement(aElement),
     95        mAttrEnum(aAttrEnum),
     96        mIsConditionalProcessingAttribute(aIsConditionalProcessingAttribute) {}
     97 
     98  ~DOMSVGStringList();
     99 
    100  SVGStringList& InternalList() const;
    101 
    102  void RemoveFromTearoffTable();
    103 
    104  // Strong ref to our element to keep it alive.
    105  RefPtr<dom::SVGElement> mElement;
    106 
    107  uint8_t mAttrEnum;
    108 
    109  bool mIsConditionalProcessingAttribute;
    110 
    111  // Tracks whether we're in the tearoff table. Initialized to true, since all
    112  // new instances are added to the table right after construction. Updated to
    113  // false when we're removed from the table (at which point we're being
    114  // destructed or soon-to-be destructed).
    115  bool mIsInTearoffTable = true;
    116 };
    117 
    118 }  // namespace dom
    119 }  // namespace mozilla
    120 
    121 #endif  // DOM_SVG_DOMSVGSTRINGLIST_H_