chromium/ui/events/event_modifiers.h

// Copyright 2014 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_EVENTS_EVENT_MODIFIERS_H_
#define UI_EVENTS_EVENT_MODIFIERS_H_

#include "ui/events/events_export.h"

namespace ui {

enum { … };

// Modifier key state for Evdev.
//
// Chrome relies on the underlying OS to interpret modifier keys such as Shift,
// Ctrl, and Alt. The Linux input subsystem does not assign any special meaning
// to these keys, so this work must happen at a higher layer (normally X11 or
// the console driver). When using evdev directly, we must do it ourselves.
//
// The modifier state is shared between all input devices connected to the
// system. This is to support actions such as Shift-Clicking that use multiple
// devices.
//
// Normally a modifier is set if any of the keys or buttons assigned to it are
// currently pressed. However some keys toggle a persistent "lock" for the
// modifier instead, such as CapsLock. If a modifier is "locked" then its state
// is inverted until it is unlocked.
class EVENTS_EXPORT EventModifiers { … };

}  // namespace ui

#endif  // UI_EVENTS_EVENT_MODIFIERS_H_