chromium/ui/base/accelerators/accelerator_map.h

// Copyright 2021 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef UI_BASE_ACCELERATORS_ACCELERATOR_MAP_H_
#define UI_BASE_ACCELERATORS_ACCELERATOR_MAP_H_

#include <map>
#include <utility>
#include <vector>

#include "base/component_export.h"
#include "build/build_config.h"
#include "ui/base/accelerators/accelerator.h"

#if BUILDFLAG(IS_CHROMEOS)
#include "ui/events/keycodes/dom/dom_code.h"
#include "ui/events/keycodes/dom/keycode_converter.h"
#endif

namespace ui {

// This is a wrapper around an internal std::map of type
// |std::map<Accelerator, V>| where |V| is the mapped value.
//
// Accelerators in Chrome on all platforms are specified with the |key_code|,
// aka VKEY, however certain keys (eg. brackets, comma, period, plus, minus),
// are in different places based on the keyboard layout. In some cases the
// VKEYs don't exist, in some cases they now conflict with other shortcuts.
//
// Chrome OS uses a positional mapping for this subset of keys. Shortcuts
// based on these keys are determined by the position of the key on a US
// keyboard. This was already the case for all non-latin alphabet keyboards
// (Chinese, Japanese, Arabic, Russian, etc.).
//
// To achieve this on Chrome OS for the remaining layouts, an additional
// remapping may happen to the accelerator used for lookup based on the state
// of |use_positional_lookup_|. When false no remapping occurs. When true,
// the |code| aka DomCode (which is by definition fixed position), is used to
// find the US layout VKEY, and that VKEY is used to lookup in the map.
//
// Other non-positional keys, eg. alphanumeric, F-keys, and special keys are
// all not remapped. Alphanumeric keys always continue to follow the
// |code|/VKEY defined by the current layout as is existing behavior.
template <typename V>
class COMPONENT_EXPORT(UI_BASE) AcceleratorMap { … };

}  // namespace ui

#endif  // UI_BASE_ACCELERATORS_ACCELERATOR_MAP_H_