blob: 71027914f51a2f94a4cde3bb9cf1b7bc8fc16dd9 [file] [log] [blame]
// Copyright 2014 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include <string>
#include "base/strings/string16.h"
#include "ui/events/keycodes/dom/dom_key.h"
#include "ui/events/keycodes/keyboard_codes.h"
#include "ui/events/ozone/layout/events_ozone_layout_export.h"
namespace ui {
enum class DomCode;
// A KeyboardLayoutEngine provides a platform-independent interface to
// key mapping. Key mapping provides a meaning (DomKey and character,
// and optionally Windows key code) for a physical key press (DomCode
// and modifier flags).
// This interface does not expose individual layouts because it must support
// platforms that only provide for one active system layout, and/or platforms
// where layouts have no accessible representation.
class EVENTS_OZONE_LAYOUT_EXPORT KeyboardLayoutEngine {
KeyboardLayoutEngine() {}
virtual ~KeyboardLayoutEngine() {}
// Returns true if it is possible to change the current layout.
virtual bool CanSetCurrentLayout() const = 0;
// Sets the current layout; returns true on success.
// Drop-in replacement for ImeKeyboard::SetCurrentKeyboardLayoutByName();
// the argument string is defined by that interface (
virtual bool SetCurrentLayoutByName(const std::string& layout_name) = 0;
// Sets the current layout given a memory location and the buffer size in
// bytes, that represent keyboard mapping description; returns true on
// success.
virtual bool SetCurrentLayoutFromBuffer(const char* keymap_string,
size_t size) = 0;
// Returns true if the current layout makes use of the ISO Level 5 Shift key.
// Drop-in replacement for ImeKeyboard::IsISOLevel5ShiftAvailable().
virtual bool UsesISOLevel5Shift() const = 0;
// Returns true if the current layout makes use of the AltGr
// (ISO Level 3 Shift) key.
// Drop-in replacement for ImeKeyboard::IsAltGrAvailable().
virtual bool UsesAltGr() const = 0;
// Provides the meaning of a physical key.
// The caller must supply valid addresses for all the output parameters;
// the function must not use their initial values.
// Returns true if it can determine the DOM meaning (i.e. ui::DomKey and
// character) and the corresponding (non-located) KeyboardCode from the given
// physical state (ui::DomCode and ui::EventFlags), OR if it can determine
// that there is no meaning in the current layout (e.g. the key is unbound).
// In the latter case, the function sets *dom_key to UNIDENTIFIED and
// *key_code to VKEY_UNKNOWN.
// Returns false if it cannot determine the meaning (and cannot determine
// that there is none); in this case it does not set any of the output
// parameters.
virtual bool Lookup(DomCode dom_code,
int event_flags,
DomKey* dom_key,
KeyboardCode* key_code) const = 0;
} // namespace ui