dom/base/nsNameSpaceManager.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 nsNameSpaceManager_h___
   8 #define nsNameSpaceManager_h___
   9
  10 #include "nsTHashMap.h"
  11 #include "nsHashKeys.h"
  12 #include "nsAtom.h"
  13 #include "nsStringFwd.h"
  14 #include "nsTArray.h"
  15
  16 #include "mozilla/StaticPtr.h"
  17
  18 /**
  19  * The Name Space Manager tracks the association between a NameSpace
  20  * URI and the int32_t runtime id. Mappings between NameSpaces and
  21  * NameSpace prefixes are managed by nsINameSpaces.
  22  *
  23  * All NameSpace URIs are stored in a global table so that IDs are
  24  * consistent accross the app. NameSpace IDs are only consistent at runtime
  25  * ie: they are not guaranteed to be consistent accross app sessions.
  26  *
  27  * The nsNameSpaceManager needs to have a live reference for as long as
  28  * the NameSpace IDs are needed.
  29  *
  30  */
  31
  32 class nsNameSpaceManager final {
  33  public:
  34   NS_INLINE_DECL_REFCOUNTING(nsNameSpaceManager)
  35
  36   nsresult RegisterNameSpace(const nsAString& aURI, int32_t& aNameSpaceID);
  37   nsresult RegisterNameSpace(already_AddRefed<nsAtom> aURI,
  38                              int32_t& aNameSpaceID);
  39
  40   nsresult GetNameSpaceURI(int32_t aNameSpaceID, nsAString& aURI);
  41
  42   // Returns the atom for the namespace URI associated with the given ID. The
  43   // ID must be within range and not be kNameSpaceID_None (i.e. zero);
  44   //
  45   // NB: The requirement of mapping from the first entry to the empty atom is
  46   // necessary for Servo, though it can be removed if needed adding a branch in
  47   // GeckoElement::get_namespace().
  48   nsAtom* NameSpaceURIAtom(int32_t aNameSpaceID) {
  49     MOZ_ASSERT(aNameSpaceID > 0);
  50     MOZ_ASSERT((int64_t)aNameSpaceID < (int64_t)mURIArray.Length());
  51     return mURIArray.ElementAt(aNameSpaceID);
  52   }
  53
  54   int32_t GetNameSpaceID(const nsAString& aURI, bool aInChromeDoc);
  55   int32_t GetNameSpaceID(nsAtom* aURI, bool aInChromeDoc);
  56
  57   static const char* GetNameSpaceDisplayName(uint32_t aNameSpaceID);
  58
  59   bool HasElementCreator(int32_t aNameSpaceID);
  60
  61   static nsNameSpaceManager* GetInstance();
  62   bool mMathMLDisabled;
  63   bool mSVGDisabled;
  64
  65  private:
  66   static void PrefChanged(const char* aPref, void* aSelf);
  67   void PrefChanged(const char* aPref);
  68
  69   bool Init();
  70   nsresult AddNameSpace(already_AddRefed<nsAtom> aURI,
  71                         const int32_t aNameSpaceID);
  72   nsresult AddDisabledNameSpace(already_AddRefed<nsAtom> aURI,
  73                                 const int32_t aNameSpaceID);
  74   ~nsNameSpaceManager() = default;
  75
  76   nsTHashMap<nsRefPtrHashKey<nsAtom>, int32_t> mURIToIDTable;
  77   nsTHashMap<nsRefPtrHashKey<nsAtom>, int32_t> mDisabledURIToIDTable;
  78   nsTArray<RefPtr<nsAtom>> mURIArray;
  79
  80   static mozilla::StaticRefPtr<nsNameSpaceManager> sInstance;
  81 };
  82
  83 #endif  // nsNameSpaceManager_h___