michael@0: /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: #ifndef mozilla_ICUUtils_h__
michael@0: #define mozilla_ICUUtils_h__
michael@0: 
michael@0: // We only build the ICU utils if we're building ICU:
michael@0: #ifdef ENABLE_INTL_API
michael@0: 
michael@0: // The ICU utils implementation needs internal things like XPCOM strings and
michael@0: // nsGkAtom, so we only build when included into internal libs:
michael@0: #ifdef MOZILLA_INTERNAL_API
michael@0: 
michael@0: #include "mozilla/Scoped.h"
michael@0: #include "nsStringGlue.h"
michael@0: #include "unicode/unum.h" // for UNumberFormat
michael@0: 
michael@0: class nsIContent;
michael@0: 
michael@0: namespace {
michael@0:   struct ScopedUNumberFormatTraits {
michael@0:     typedef UNumberFormat* type;
michael@0:     static type empty() { return nullptr; }
michael@0:     static void release(type handle) { if (handle) unum_close(handle); }
michael@0:   };
michael@0: };
michael@0: typedef mozilla::Scoped<ScopedUNumberFormatTraits> AutoCloseUNumberFormat;
michael@0: 
michael@0: class ICUUtils
michael@0: {
michael@0: public:
michael@0: 
michael@0:   /**
michael@0:    * This class is used to encapsulate an nsIContent object to allow lazy
michael@0:    * iteration over its primary and fallback BCP 47 language tags.
michael@0:    */
michael@0:   class LanguageTagIterForContent {
michael@0:   public:
michael@0:     LanguageTagIterForContent(nsIContent* aContent)
michael@0:       : mContent(aContent)
michael@0:       , mCurrentFallbackIndex(-1)
michael@0:     {}
michael@0: 
michael@0:     /**
michael@0:      * Used to iterate over the nsIContent object's primary language tag and
michael@0:      * its fallbacks tags. The following sources of language tag information
michael@0:      * are tried in turn:
michael@0:      *
michael@0:      * 1) the "lang" of the nsIContent object (which is based on the 'lang'/
michael@0:      *    'xml:lang' attribute on itself or the nearest ancestor to have such
michael@0:      *    an attribute, if any);
michael@0:      * 2) the Content-Language HTTP pragma directive or HTTP header;
michael@0:      * 3) the configured language tag of the user-agent.
michael@0:      *
michael@0:      * Once all fallbacks have been exhausted then this function will set
michael@0:      * aBCP47LangTag to the empty string.
michael@0:      */
michael@0:     void GetNext(nsACString& aBCP47LangTag);
michael@0: 
michael@0:     bool IsAtStart() const {
michael@0:       return mCurrentFallbackIndex < 0;
michael@0:     }
michael@0: 
michael@0:   private:
michael@0:     nsIContent* mContent;
michael@0:     int8_t mCurrentFallbackIndex;
michael@0:   };
michael@0: 
michael@0:   /**
michael@0:    * Attempts to localize aValue and return the result via the aLocalizedValue
michael@0:    * outparam. Returns true on success. Returns false on failure, in which
michael@0:    * case aLocalizedValue will be untouched.
michael@0:    */
michael@0:   static bool LocalizeNumber(double aValue,
michael@0:                              LanguageTagIterForContent& aLangTags,
michael@0:                              nsAString& aLocalizedValue);
michael@0: 
michael@0:   /**
michael@0:    * Parses the localized number that is serialized in aValue using aLangTags
michael@0:    * and returns the result as a double. Returns NaN on failure.
michael@0:    */
michael@0:   static double ParseNumber(nsAString& aValue,
michael@0:                             LanguageTagIterForContent& aLangTags);
michael@0: 
michael@0:   static void AssignUCharArrayToString(UChar* aICUString,
michael@0:                                        int32_t aLength,
michael@0:                                        nsAString& aMozString);
michael@0: 
michael@0: #if 0
michael@0:   // Currently disabled because using C++ API doesn't play nicely with enabling
michael@0:   // system ICU.
michael@0: 
michael@0:   /**
michael@0:    * Converts an IETF BCP 47 language code to an ICU Locale.
michael@0:    */
michael@0:   static Locale BCP47CodeToLocale(const nsAString& aBCP47Code);
michael@0: 
michael@0:   static void ToMozString(UnicodeString& aICUString, nsAString& aMozString);
michael@0:   static void ToICUString(nsAString& aMozString, UnicodeString& aICUString);
michael@0: #endif
michael@0: };
michael@0: 
michael@0: #endif /* ENABLE_INTL_API */
michael@0: #endif /* MOZILLA_INTERNAL_API */
michael@0: 
michael@0: #endif /* mozilla_ICUUtils_h__ */
michael@0: