1 // Copyright 2013 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_H_ 6 #define UI_EVENTS_OZONE_EVDEV_EVENT_MODIFIERS_H_ 7 8 #include "ui/events/events_export.h" 9 #include "ui/events/ozone/event_converter_ozone.h" 10 11 namespace ui { 12 13 enum { 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. 42 class EVENTS_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 private: 57 // Count of keys pressed for each modifier. 58 int modifiers_down_[EVDEV_NUM_MODIFIERS]; 59 60 // Mask of modifier flags currently "locked". 61 int modifier_flags_locked_; 62 63 // Mask of modifier flags currently active (nonzero keys pressed xor locked). 64 int modifier_flags_; 65 66 // Update modifier_flags_ from modifiers_down_ and modifier_flags_locked_. 67 void UpdateFlags(unsigned int modifier); 68 69 DISALLOW_COPY_AND_ASSIGN(EventModifiersEvdev); 70 }; 71 72 } // namspace ui 73 74 #endif // UI_EVENTS_OZONE_EVDEV_EVENT_MODIFIERS_H_ 75