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40 lines
2.0 KiB
C++
40 lines
2.0 KiB
C++
// Copyright (c) 2011 The Chromium Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style license that can be
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// found in the LICENSE file.
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#ifndef UI_EVENTS_KEYCODES_KEYBOARD_CODE_CONVERSION_H_
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#define UI_EVENTS_KEYCODES_KEYBOARD_CODE_CONVERSION_H_
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#include "base/basictypes.h"
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#include "ui/events/events_base_export.h"
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#include "ui/events/keycodes/keyboard_codes.h"
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namespace ui {
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// A helper function to get the character generated by a key event in a
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// platform independent way. It supports control characters as well.
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// It assumes a US keyboard layout is used, so it may only be used when there
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// is no native event or no better way to get the character.
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// For example, if a virtual keyboard implementation can only generate key
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// events with key_code and flags information, then there is no way for us to
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// determine the actual character that should be generate by the key. Because
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// a key_code only represents a physical key on the keyboard, it has nothing
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// to do with the actual character printed on that key. In such case, the only
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// thing we can do is to assume that we are using a US keyboard and get the
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// character according to US keyboard layout definition.
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// If a virtual keyboard implementation wants to support other keyboard
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// layouts, that may generate different text for a certain key than on a US
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// keyboard, a special native event object should be introduced to carry extra
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// information to help determine the correct character.
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// Take XKeyEvent as an example, it contains not only keycode and modifier
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// flags but also group and other extra XKB information to help determine the
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// correct character. That's why we can use XLookupString() function to get
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// the correct text generated by a X key event (See how is GetCharacter()
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// implemented in event_x.cc).
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EVENTS_BASE_EXPORT uint16 GetCharacterFromKeyCode(KeyboardCode key_code,
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int flags);
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} // namespace ui
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#endif // UI_EVENTS_KEYCODES_KEYBOARD_CODE_CONVERSION_H_
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