ui/app_list/search/term_break_iterator.h

   1 // Copyright 2013 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.
   4
   5 #ifndef UI_APP_LIST_SEARCH_TERM_BREAK_ITERATOR_H_
   6 #define UI_APP_LIST_SEARCH_TERM_BREAK_ITERATOR_H_
   7
   8 #include "base/basictypes.h"
   9 #include "base/memory/scoped_ptr.h"
  10 #include "base/strings/string16.h"
  11 #include "ui/app_list/app_list_export.h"
  12
  13 namespace base {
  14 namespace i18n {
  15 class UTF16CharIterator;
  16 }
  17 }
  18
  19 namespace app_list {
  20
  21 // TermBreakIterator breaks terms out of a word. Terms are broken on
  22 // camel case boundaries and alpha/number boundaries. Numbers are defined
  23 // as [0-9\.,]+.
  24 //  e.g.
  25 //   CamelCase -> Camel, Case
  26 //   Python2.7 -> Python, 2.7
  27 class APP_LIST_EXPORT TermBreakIterator {
  28  public:
  29   // Note that |word| must out live this iterator.
  30   explicit TermBreakIterator(const base::string16& word);
  31   ~TermBreakIterator();
  32
  33   // Advance to the next term. Returns false if at the end of the word.
  34   bool Advance();
  35
  36   // Returns the current term, which is the substr of |word_| in range
  37   // [prev_, pos_).
  38   const base::string16 GetCurrentTerm() const;
  39
  40   size_t prev() const { return prev_; }
  41   size_t pos() const { return pos_; }
  42
  43   static const size_t npos = static_cast<size_t>(-1);
  44
  45  private:
  46   enum State {
  47     STATE_START,   // Initial state
  48     STATE_NUMBER,  // Current char is a number [0-9\.,].
  49     STATE_UPPER,   // Current char is upper case.
  50     STATE_LOWER,   // Current char is lower case.
  51     STATE_CHAR,    // Current char has no case, e.g. a cjk char.
  52     STATE_LAST,
  53   };
  54
  55   // Returns new state for given |ch|.
  56   State GetNewState(base::char16 ch);
  57
  58   const base::string16& word_;
  59   size_t prev_;
  60   size_t pos_;
  61
  62   scoped_ptr<base::i18n::UTF16CharIterator> iter_;
  63   State state_;
  64
  65   DISALLOW_COPY_AND_ASSIGN(TermBreakIterator);
  66 };
  67
  68 }  // namespace app_list
  69
  70 #endif  // UI_APP_LIST_SEARCH_TERM_BREAK_ITERATOR_H_