ui/events/ozone/layout/xkb/xkb_keyboard_layout_engine.h

   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_LAYOUT_XKB_XKB_KEYBOARD_LAYOUT_ENGINE_H_
   6 #define UI_EVENTS_OZONE_LAYOUT_XKB_XKB_KEYBOARD_LAYOUT_ENGINE_H_
   7
   8 #include <xkbcommon/xkbcommon.h>
   9 #include <vector>
  10
  11 #include "base/containers/hash_tables.h"
  12 #include "base/memory/ref_counted.h"
  13 #include "base/memory/scoped_ptr.h"
  14 #include "base/memory/weak_ptr.h"
  15 #include "base/strings/string16.h"
  16 #include "base/task_runner.h"
  17 #include "ui/events/ozone/layout/events_ozone_layout_export.h"
  18 #include "ui/events/ozone/layout/keyboard_layout_engine.h"
  19 #include "ui/events/ozone/layout/xkb/scoped_xkb.h"
  20 #include "ui/events/ozone/layout/xkb/xkb_key_code_converter.h"
  21
  22 namespace ui {
  23
  24 class EVENTS_OZONE_LAYOUT_EXPORT XkbKeyboardLayoutEngine
  25     : public KeyboardLayoutEngine {
  26  public:
  27   XkbKeyboardLayoutEngine(const XkbKeyCodeConverter& converter);
  28   ~XkbKeyboardLayoutEngine() override;
  29
  30   // KeyboardLayoutEngine:
  31   bool CanSetCurrentLayout() const override;
  32   bool SetCurrentLayoutByName(const std::string& layout_name) override;
  33
  34   bool UsesISOLevel5Shift() const override;
  35   bool UsesAltGr() const override;
  36
  37   bool Lookup(DomCode dom_code,
  38               int flags,
  39               DomKey* dom_key,
  40               base::char16* character,
  41               KeyboardCode* key_code,
  42               uint32* platform_keycode) const override;
  43
  44   static void ParseLayoutName(const std::string& layout_name,
  45                               std::string* layout_id,
  46                               std::string* layout_variant);
  47
  48  protected:
  49   // Table for EventFlagsToXkbFlags().
  50   struct XkbFlagMapEntry {
  51     int ui_flag;
  52     xkb_mod_mask_t xkb_flag;
  53   };
  54   std::vector<XkbFlagMapEntry> xkb_flag_map_;
  55
  56   // Flag mask for num lock, which is always considered enabled.
  57   xkb_mod_mask_t num_lock_mod_mask_ = 0;
  58
  59   // Determines the Windows-based KeyboardCode (VKEY) for a character key,
  60   // accounting for non-US layouts. May return VKEY_UNKNOWN, in which case the
  61   // caller should, as a last resort, obtain a KeyboardCode using
  62   // |DomCodeToUsLayoutMeaning()|.
  63   KeyboardCode DifficultKeyboardCode(DomCode dom_code,
  64                                      int ui_flags,
  65                                      xkb_keycode_t xkb_keycode,
  66                                      xkb_mod_mask_t xkb_flags,
  67                                      xkb_keysym_t xkb_keysym,
  68                                      DomKey dom_key,
  69                                      base::char16 character) const;
  70
  71   // Maps DomCode to xkb_keycode_t.
  72   const XkbKeyCodeConverter& key_code_converter_;
  73
  74  private:
  75   struct XkbKeymapEntry {
  76     std::string layout_name;
  77     xkb_keymap* keymap;
  78   };
  79   std::vector<XkbKeymapEntry> xkb_keymaps_;
  80   // Sets a new XKB keymap. This updates xkb_state_ (which takes ownership
  81   // of the keymap), and updates xkb_flag_map_ for the new keymap.
  82   void SetKeymap(xkb_keymap* keymap);
  83
  84   // Returns the XKB modifiers flags corresponding to the given EventFlags.
  85   xkb_mod_mask_t EventFlagsToXkbFlags(int ui_flags) const;
  86
  87   // Determines the XKB KeySym and character associated with a key.
  88   // Returns true on success. This is virtual for testing.
  89   virtual bool XkbLookup(xkb_keycode_t xkb_keycode,
  90                          xkb_mod_mask_t xkb_flags,
  91                          xkb_keysym_t* xkb_keysym,
  92                          base::char16* character) const;
  93
  94   // Helper for difficult VKEY lookup. If |ui_flags| matches |base_flags|,
  95   // returns |base_character|; otherwise returns the XKB character for
  96   // the keycode and mapped |ui_flags|.
  97   base::char16 XkbSubCharacter(xkb_keycode_t xkb_keycode,
  98                                xkb_mod_mask_t base_flags,
  99                                base::char16 base_character,
 100                                int ui_flags) const;
 101
 102   // Callback when keymap file is loaded complete.
 103   void OnKeymapLoaded(const std::string& layout_name,
 104                       scoped_ptr<char, base::FreeDeleter> keymap_str);
 105
 106   // libxkbcommon uses explicit reference counting for its structures,
 107   // so we need to trigger its cleanup.
 108   scoped_ptr<xkb_context, XkbContextDeleter> xkb_context_;
 109   scoped_ptr<xkb_state, XkbStateDeleter> xkb_state_;
 110
 111   std::string current_layout_name_;
 112
 113   // Support weak pointers for attach & detach callbacks.
 114   base::WeakPtrFactory<XkbKeyboardLayoutEngine> weak_ptr_factory_;
 115 };
 116
 117 }  // namespace ui
 118
 119 #endif  // UI_EVENTS_OZONE_LAYOUT_XKB_XKB_KEYBOARD_LAYOUT_ENGINE_H_