dom/encoding/FallbackEncoding.h

   1 /* This Source Code Form is subject to the terms of the Mozilla Public
   2  * License, v. 2.0. If a copy of the MPL was not distributed with this file,
   3  * You can obtain one at http://mozilla.org/MPL/2.0/. */
   4
   5 #ifndef mozilla_dom_FallbackEncoding_h_
   6 #define mozilla_dom_FallbackEncoding_h_
   7
   8 #include "nsString.h"
   9
  10 namespace mozilla {
  11 namespace dom {
  12
  13 class FallbackEncoding
  14 {
  15 public:
  16
  17   /**
  18    * Whether FromTopLevelDomain() should be used.
  19    */
  20   static bool sGuessFallbackFromTopLevelDomain;
  21
  22   /**
  23    * Gets the locale-dependent fallback encoding for legacy HTML and plain
  24    * text content.
  25    *
  26    * @param aFallback the outparam for the fallback encoding
  27    */
  28   static void FromLocale(nsACString& aFallback);
  29
  30   /**
  31    * Checks if it is appropriate to call FromTopLevelDomain() for a given TLD.
  32    *
  33    * @param aTLD the top-level domain (in Punycode)
  34    * @return true if OK to call FromTopLevelDomain()
  35    */
  36   static bool IsParticipatingTopLevelDomain(const nsACString& aTLD);
  37
  38   /**
  39    * Gets a top-level domain-depedendent fallback encoding for legacy HTML
  40    * and plain text content
  41    *
  42    * @param aTLD the top-level domain (in Punycode)
  43    * @param aFallback the outparam for the fallback encoding
  44    */
  45   static void FromTopLevelDomain(const nsACString& aTLD, nsACString& aFallback);
  46
  47   // public API ends here!
  48
  49   /**
  50    * Allocate sInstance used by FromLocale().
  51    * To be called from nsLayoutStatics only.
  52    */
  53   static void Initialize();
  54
  55   /**
  56    * Delete sInstance used by FromLocale().
  57    * To be called from nsLayoutStatics only.
  58    */
  59   static void Shutdown();
  60
  61 private:
  62
  63   /**
  64    * The fallback cache.
  65    */
  66   static FallbackEncoding* sInstance;
  67
  68   FallbackEncoding();
  69   ~FallbackEncoding();
  70
  71   /**
  72    * Invalidates the cache.
  73    */
  74   void Invalidate()
  75   {
  76     mFallback.Truncate();
  77   }
  78
  79   static void PrefChanged(const char*, void*);
  80
  81   /**
  82    * Gets the fallback encoding label.
  83    * @param aFallback the fallback encoding
  84    */
  85   void Get(nsACString& aFallback);
  86
  87   nsCString mFallback;
  88 };
  89
  90 } // dom
  91 } // mozilla
  92
  93 #endif // mozilla_dom_FallbackEncoding_h_
  94