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_BASE_IME_CHROMEOS_CHARACTER_COMPOSER_H_ 6 #define UI_BASE_IME_CHROMEOS_CHARACTER_COMPOSER_H_ 7 8 #include <vector> 9 10 #include "base/strings/string_util.h" 11 #include "ui/base/ui_export.h" 12 13 namespace ui { 14 class KeyEvent; 15 16 // A class to recognize compose and dead key sequence. 17 // Outputs composed character. 18 class UI_EXPORT CharacterComposer { 19 public: 20 CharacterComposer(); 21 ~CharacterComposer(); 22 23 void Reset(); 24 25 // Filters keypress. 26 // Returns true if the keypress is recognized as a part of composition 27 // sequence. 28 // Fabricated events which don't have the native event, are not supported. 29 bool FilterKeyPress(const ui::KeyEvent& event); 30 31 // Returns a string consisting of composed character. 32 // Empty string is returned when there is no composition result. 33 const string16& composed_character() const { return composed_character_; } 34 35 // Returns the preedit string. 36 const string16& preedit_string() const { return preedit_string_; } 37 38 private: 39 friend class CharacterComposerTest; 40 41 // An enum to describe composition mode. 42 enum CompositionMode { 43 // This is the initial state. 44 // Composite a character with dead-keys and compose-key. 45 KEY_SEQUENCE_MODE, 46 // Composite a character with a hexadecimal unicode sequence. 47 HEX_MODE, 48 }; 49 50 // Filters keypress using IBus defined value. 51 // Returns true if the keypress is recognized as a part of composition 52 // sequence. 53 // |keyval| must be a GDK_KEY_* constant. 54 // |keycode| must be a X key code. 55 // |flags| must be a combination of ui::EF_* flags. 56 // 57 // composed_character() returns non empty string when there is a character 58 // composed after this method returns true. 59 // preedit_string() returns non empty string when there is a preedit string 60 // after this method returns true. 61 // Return values of preedit_string() is empty after this method returns false. 62 // composed_character() may have some characters which are consumed in this 63 // composing session. 64 // 65 // 66 // TODO(nona): Actually a X KeySym is passed to |keyval|, so we should use 67 // XK_* rather than GDK_KEY_*. 68 bool FilterKeyPressInternal(unsigned int keyval, unsigned int keycode, 69 int flags); 70 71 // Filters keypress in key sequence mode. 72 bool FilterKeyPressSequenceMode(unsigned int keyval, int flags); 73 74 // Filters keypress in hexadecimal mode. 75 bool FilterKeyPressHexMode(unsigned int keyval, unsigned int keycode, 76 int flags); 77 78 // Commit a character composed from hexadecimal uncode sequence 79 void CommitHex(); 80 81 // Updates preedit string in hexadecimal mode. 82 void UpdatePreeditStringHexMode(); 83 84 // Remembers keypresses previously filtered. 85 std::vector<unsigned int> compose_buffer_; 86 87 // A string representing the composed character. 88 string16 composed_character_; 89 90 // Preedit string. 91 string16 preedit_string_; 92 93 // Composition mode which this instance is in. 94 CompositionMode composition_mode_; 95 96 DISALLOW_COPY_AND_ASSIGN(CharacterComposer); 97 }; 98 99 } // namespace ui 100 101 #endif // UI_BASE_IME_CHROMEOS_CHARACTER_COMPOSER_H_ 102
