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.
4
5#ifndef UI_EVENTS_KEYCODES_KEYBOARD_CODE_CONVERSION_H_
6#define UI_EVENTS_KEYCODES_KEYBOARD_CODE_CONVERSION_H_
7
8#include "base/basictypes.h"
9#include "ui/events/events_base_export.h"
10#include "ui/events/keycodes/keyboard_codes.h"
11
12namespace ui {
13
14// A helper function to get the character generated by a key event in a
15// platform independent way. It supports control characters as well.
16// It assumes a US keyboard layout is used, so it may only be used when there
17// is no native event or no better way to get the character.
18// For example, if a virtual keyboard implementation can only generate key
19// events with key_code and flags information, then there is no way for us to
20// determine the actual character that should be generate by the key. Because
21// a key_code only represents a physical key on the keyboard, it has nothing
22// to do with the actual character printed on that key. In such case, the only
23// thing we can do is to assume that we are using a US keyboard and get the
24// character according to US keyboard layout definition.
25// If a virtual keyboard implementation wants to support other keyboard
26// layouts, that may generate different text for a certain key than on a US
27// keyboard, a special native event object should be introduced to carry extra
28// information to help determine the correct character.
29// Take XKeyEvent as an example, it contains not only keycode and modifier
30// flags but also group and other extra XKB information to help determine the
31// correct character. That's why we can use XLookupString() function to get
32// the correct text generated by a X key event (See how is GetCharacter()
33// implemented in event_x.cc).
34EVENTS_BASE_EXPORT uint16 GetCharacterFromKeyCode(KeyboardCode key_code,
35                                                  int flags);
36
37}  // namespace ui
38
39#endif  // UI_EVENTS_KEYCODES_KEYBOARD_CODE_CONVERSION_H_
40