1 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
5 #ifndef UI_BASE_L10N_L10N_UTIL_COLLATOR_H_
6 #define UI_BASE_L10N_L10N_UTIL_COLLATOR_H_
13 #include "base/i18n/string_compare.h"
14 #include "base/memory/scoped_ptr.h"
15 #include "third_party/icu/source/i18n/unicode/coll.h"
16 #include "ui/base/ui_export.h"
20 // Used by SortStringsUsingMethod. Invokes a method on the objects passed to
21 // operator (), comparing the string results using a collator.
22 template <class T
, class Method
>
23 class StringMethodComparatorWithCollator
24 : public std::binary_function
<const base::string16
&,
25 const base::string16
&,
28 StringMethodComparatorWithCollator(icu::Collator
* collator
, Method method
)
29 : collator_(collator
),
32 // Returns true if lhs preceeds rhs.
33 bool operator() (T
* lhs_t
, T
* rhs_t
) {
34 return base::i18n::CompareString16WithCollator(collator_
,
35 (lhs_t
->*method_
)(), (rhs_t
->*method_
)()) == UCOL_LESS
;
39 icu::Collator
* collator_
;
43 // Used by SortStringsUsingMethod. Invokes a method on the objects passed to
44 // operator (), comparing the string results using <.
45 template <class T
, class Method
>
46 class StringMethodComparator
47 : public std::binary_function
<const base::string16
&,
48 const base::string16
&,
51 explicit StringMethodComparator(Method method
) : method_(method
) { }
53 // Returns true if lhs preceeds rhs.
54 bool operator() (T
* lhs_t
, T
* rhs_t
) {
55 return (lhs_t
->*method_
)() < (rhs_t
->*method_
)();
62 // Sorts the objects in |elements| using the method |method|, which must return
63 // a string. Sorting is done using a collator, unless a collator can not be
64 // found in which case the strings are sorted using the operator <.
65 template <class T
, class Method
>
66 void SortStringsUsingMethod(const std::string
& locale
,
67 std::vector
<T
*>* elements
,
69 UErrorCode error
= U_ZERO_ERROR
;
70 icu::Locale
loc(locale
.c_str());
71 scoped_ptr
<icu::Collator
> collator(icu::Collator::createInstance(loc
, error
));
72 if (U_FAILURE(error
)) {
73 sort(elements
->begin(), elements
->end(),
74 StringMethodComparator
<T
, Method
>(method
));
78 std::sort(elements
->begin(), elements
->end(),
79 StringMethodComparatorWithCollator
<T
, Method
>(collator
.get(), method
));
82 // Compares two elements' string keys and returns true if the first element's
83 // string key is less than the second element's string key. The Element must
84 // have a method like the follow format to return the string key.
85 // const base::string16& GetStringKey() const;
86 // This uses the locale specified in the constructor.
87 template <class Element
>
88 class StringComparator
: public std::binary_function
<const Element
&,
92 explicit StringComparator(icu::Collator
* collator
)
93 : collator_(collator
) { }
95 // Returns true if lhs precedes rhs.
96 bool operator()(const Element
& lhs
, const Element
& rhs
) {
97 const base::string16
& lhs_string_key
= lhs
.GetStringKey();
98 const base::string16
& rhs_string_key
= rhs
.GetStringKey();
100 return StringComparator
<base::string16
>(collator_
)(lhs_string_key
,
105 icu::Collator
* collator_
;
108 // Specialization of operator() method for base::string16 version.
109 template <> UI_EXPORT
110 bool StringComparator
<base::string16
>::operator()(const base::string16
& lhs
,
111 const base::string16
& rhs
);
113 // In place sorting of |elements| of a vector according to the string key of
114 // each element in the vector by using collation rules for |locale|.
115 // |begin_index| points to the start position of elements in the vector which
116 // want to be sorted. |end_index| points to the end position of elements in the
117 // vector which want to be sorted
118 template <class Element
>
119 void SortVectorWithStringKey(const std::string
& locale
,
120 std::vector
<Element
>* elements
,
121 unsigned int begin_index
,
122 unsigned int end_index
,
123 bool needs_stable_sort
) {
124 DCHECK(begin_index
< end_index
&&
125 end_index
<= static_cast<unsigned int>(elements
->size()));
126 UErrorCode error
= U_ZERO_ERROR
;
127 icu::Locale
loc(locale
.c_str());
128 scoped_ptr
<icu::Collator
> collator(icu::Collator::createInstance(loc
, error
));
129 if (U_FAILURE(error
))
131 StringComparator
<Element
> c(collator
.get());
132 if (needs_stable_sort
) {
133 stable_sort(elements
->begin() + begin_index
,
134 elements
->begin() + end_index
,
137 sort(elements
->begin() + begin_index
, elements
->begin() + end_index
, c
);
141 template <class Element
>
142 void SortVectorWithStringKey(const std::string
& locale
,
143 std::vector
<Element
>* elements
,
144 bool needs_stable_sort
) {
145 SortVectorWithStringKey
<Element
>(locale
, elements
, 0, elements
->size(),
149 } // namespace l10n_util
151 #endif // UI_BASE_L10N_L10N_UTIL_COLLATOR_H_