dom/svg/DOMSVGStringList.h

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