gecko-dev/intl/unicharutil/util/ICUUtils.h

110 lines
3.4 KiB
C++

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