1// Copyright 2014 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_OZONE_EVDEV_EVENT_MODIFIERS_EVDEV_H_ 6#define UI_EVENTS_OZONE_EVDEV_EVENT_MODIFIERS_EVDEV_H_ 7 8#include "base/basictypes.h" 9#include "ui/events/ozone/evdev/events_ozone_evdev_export.h" 10 11namespace ui { 12 13enum { 14 EVDEV_MODIFIER_NONE, 15 EVDEV_MODIFIER_CAPS_LOCK, 16 EVDEV_MODIFIER_SHIFT, 17 EVDEV_MODIFIER_CONTROL, 18 EVDEV_MODIFIER_ALT, 19 EVDEV_MODIFIER_LEFT_MOUSE_BUTTON, 20 EVDEV_MODIFIER_MIDDLE_MOUSE_BUTTON, 21 EVDEV_MODIFIER_RIGHT_MOUSE_BUTTON, 22 EVDEV_MODIFIER_COMMAND, 23 EVDEV_MODIFIER_ALTGR, 24 EVDEV_NUM_MODIFIERS 25}; 26 27// Modifier key state for Evdev. 28// 29// Chrome relies on the underlying OS to interpret modifier keys such as Shift, 30// Ctrl, and Alt. The Linux input subsystem does not assign any special meaning 31// to these keys, so this work must happen at a higher layer (normally X11 or 32// the console driver). When using evdev directly, we must do it ourselves. 33// 34// The modifier state is shared between all input devices connected to the 35// system. This is to support actions such as Shift-Clicking that use multiple 36// devices. 37// 38// Normally a modifier is set if any of the keys or buttons assigned to it are 39// currently pressed. However some keys toggle a persistent "lock" for the 40// modifier instead, such as CapsLock. If a modifier is "locked" then its state 41// is inverted until it is unlocked. 42class EVENTS_OZONE_EVDEV_EXPORT EventModifiersEvdev { 43 public: 44 EventModifiersEvdev(); 45 ~EventModifiersEvdev(); 46 47 // Record key press or release for regular modifier key (shift, alt, etc). 48 void UpdateModifier(unsigned int modifier, bool down); 49 50 // Record key press or release for locking modifier key (caps lock). 51 void UpdateModifierLock(unsigned int modifier, bool down); 52 53 // Return current flags to use for incoming events. 54 int GetModifierFlags(); 55 56 // Return the mask for the specified modifier. 57 static int GetEventFlagFromModifier(unsigned int modifier); 58 59 private: 60 // Count of keys pressed for each modifier. 61 int modifiers_down_[EVDEV_NUM_MODIFIERS]; 62 63 // Mask of modifier flags currently "locked". 64 int modifier_flags_locked_; 65 66 // Mask of modifier flags currently active (nonzero keys pressed xor locked). 67 int modifier_flags_; 68 69 // Update modifier_flags_ from modifiers_down_ and modifier_flags_locked_. 70 void UpdateFlags(unsigned int modifier); 71 72 DISALLOW_COPY_AND_ASSIGN(EventModifiersEvdev); 73}; 74 75} // namspace ui 76 77#endif // UI_EVENTS_OZONE_EVDEV_EVENT_MODIFIERS_EVDEV_H_ 78