| // Copyright (c) 2011 The Chromium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #ifndef UI_BASE_L10N_L10N_UTIL_COLLATOR_H_ |
| #define UI_BASE_L10N_L10N_UTIL_COLLATOR_H_ |
| |
| #include <stddef.h> |
| |
| #include <algorithm> |
| #include <functional> |
| #include <memory> |
| #include <string> |
| #include <vector> |
| |
| #include "base/i18n/string_compare.h" |
| #include "third_party/icu/source/i18n/unicode/coll.h" |
| #include "ui/base/ui_base_export.h" |
| |
| namespace l10n_util { |
| |
| // Used by SortStringsUsingMethod. Invokes a method on the objects passed to |
| // operator (), comparing the string results using a collator. |
| template <class T, class Method> |
| class StringMethodComparatorWithCollator { |
| public: |
| StringMethodComparatorWithCollator(icu::Collator* collator, Method method) |
| : collator_(collator), |
| method_(method) { } |
| |
| // Returns true if lhs precedes rhs. |
| bool operator()(const std::unique_ptr<T>& lhs_t, |
| const std::unique_ptr<T>& rhs_t) { |
| return base::i18n::CompareString16WithCollator( |
| *collator_, (lhs_t.get()->*method_)(), |
| (rhs_t.get()->*method_)()) == UCOL_LESS; |
| } |
| |
| private: |
| icu::Collator* collator_; |
| Method method_; |
| }; |
| |
| // Used by SortStringsUsingMethod. Invokes a method on the objects passed to |
| // operator (), comparing the string results using <. |
| template <class T, class Method> |
| class StringMethodComparator { |
| public: |
| explicit StringMethodComparator(Method method) : method_(method) { } |
| |
| // Returns true if lhs precedes rhs. |
| bool operator()(const std::unique_ptr<T>& lhs_t, |
| const std::unique_ptr<T>& rhs_t) { |
| return (lhs_t.get()->*method_)() < (rhs_t.get()->*method_)(); |
| } |
| |
| private: |
| Method method_; |
| }; |
| |
| // Sorts the objects in |elements| using the method |method|, which must return |
| // a string. Sorting is done using a collator, unless a collator can not be |
| // found in which case the strings are sorted using the operator <. |
| template <class T, class Method> |
| void SortStringsUsingMethod(const std::string& locale, |
| std::vector<std::unique_ptr<T>>* elements, |
| Method method) { |
| UErrorCode error = U_ZERO_ERROR; |
| icu::Locale loc(locale.c_str()); |
| std::unique_ptr<icu::Collator> collator( |
| icu::Collator::createInstance(loc, error)); |
| if (U_FAILURE(error)) { |
| sort(elements->begin(), elements->end(), |
| StringMethodComparator<T, Method>(method)); |
| return; |
| } |
| |
| std::sort(elements->begin(), elements->end(), |
| StringMethodComparatorWithCollator<T, Method>(collator.get(), method)); |
| } |
| |
| // Compares two elements' string keys and returns true if the first element's |
| // string key is less than the second element's string key. The Element must |
| // have a method like the follow format to return the string key. |
| // const base::string16& GetStringKey() const; |
| // This uses the locale specified in the constructor. |
| template <class Element> |
| class StringComparator { |
| public: |
| explicit StringComparator(icu::Collator* collator) |
| : collator_(collator) { } |
| |
| // Returns true if lhs precedes rhs. |
| bool operator()(const Element& lhs, const Element& rhs) const { |
| const base::string16& lhs_string_key = lhs.GetStringKey(); |
| const base::string16& rhs_string_key = rhs.GetStringKey(); |
| |
| return StringComparator<base::string16>(collator_)(lhs_string_key, |
| rhs_string_key); |
| } |
| |
| private: |
| icu::Collator* collator_; |
| }; |
| |
| // Specialization of operator() method for base::string16 version. |
| template <> |
| UI_BASE_EXPORT inline bool StringComparator<base::string16>::operator()( |
| const base::string16& lhs, |
| const base::string16& rhs) const { |
| // If we can not get collator instance for specified locale, just do simple |
| // string compare. |
| if (!collator_) |
| return lhs < rhs; |
| return base::i18n::CompareString16WithCollator(*collator_, lhs, rhs) == |
| UCOL_LESS; |
| } |
| |
| // In place sorting of |elements| of a vector according to the string key of |
| // each element in the vector by using collation rules for |locale|. |
| // |begin_index| points to the start position of elements in the vector which |
| // want to be sorted. |end_index| points to the end position of elements in the |
| // vector which want to be sorted. |
| template <class Element> |
| void SortVectorWithStringKey(const std::string& locale, |
| std::vector<Element>* elements, |
| size_t begin_index, |
| size_t end_index, |
| bool needs_stable_sort) { |
| DCHECK_LT(begin_index, end_index); |
| DCHECK_LE(end_index, elements->size()); |
| UErrorCode error = U_ZERO_ERROR; |
| icu::Locale loc(locale.c_str()); |
| std::unique_ptr<icu::Collator> collator( |
| icu::Collator::createInstance(loc, error)); |
| if (U_FAILURE(error)) |
| collator.reset(); |
| StringComparator<Element> c(collator.get()); |
| if (needs_stable_sort) { |
| stable_sort(elements->begin() + begin_index, |
| elements->begin() + end_index, |
| c); |
| } else { |
| sort(elements->begin() + begin_index, elements->begin() + end_index, c); |
| } |
| } |
| |
| template <class Element> |
| void SortVectorWithStringKey(const std::string& locale, |
| std::vector<Element>* elements, |
| bool needs_stable_sort) { |
| SortVectorWithStringKey<Element>(locale, elements, 0, elements->size(), |
| needs_stable_sort); |
| } |
| |
| } // namespace l10n_util |
| |
| #endif // UI_BASE_L10N_L10N_UTIL_COLLATOR_H_ |