XKB implementation of Ozone key layout.

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

+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef UI_EVENTS_OZONE_LAYOUT_XKB_XKB_KEYBOARD_LAYOUT_ENGINE_H_
+#define UI_EVENTS_OZONE_LAYOUT_XKB_XKB_KEYBOARD_LAYOUT_ENGINE_H_
+
+#include <xkbcommon/xkbcommon.h>
+
+#include "base/containers/hash_tables.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/strings/string16.h"
+#include "ui/events/ozone/layout/events_ozone_layout_export.h"
+#include "ui/events/ozone/layout/keyboard_layout_engine.h"
+
+namespace ui {
+
+class EVENTS_OZONE_LAYOUT_EXPORT XkbKeyCodeConverter {
+ public:
+  XkbKeyCodeConverter();
+  virtual ~XkbKeyCodeConverter();
+  xkb_keycode_t InvalidXkbKeyCode() const { return invalid_xkb_keycode_; }
+  virtual xkb_keycode_t DomCodeToXkbKeyCode(DomCode dom_code) const = 0;
+
+ protected:
+  xkb_keycode_t invalid_xkb_keycode_;
+};
+
+class EVENTS_OZONE_LAYOUT_EXPORT XkbKeyboardLayoutEngine
+    : public KeyboardLayoutEngine {
+ public:
+  XkbKeyboardLayoutEngine(const XkbKeyCodeConverter& converter);
+  virtual ~XkbKeyboardLayoutEngine();
+
+  // KeyboardLayoutEngine:
+  virtual bool CanSetCurrentLayout() const override;
+  virtual bool SetCurrentLayoutByName(const std::string& layout_name) override;
+
+  virtual bool UsesISOLevel5Shift() const override;
+  virtual bool UsesAltGr() const override;
+
+  virtual bool Lookup(DomCode dom_code,
+                      int flags,
+                      DomKey* dom_key,
+                      base::char16* character,
+                      KeyboardCode* key_code) const override;
+
+ private:
+  // Sets a new XKB keymap, updating object fields.
+  void SetKeymap(xkb_keymap* keymap);
+
+  // Returns the XKB modifiers flags corresponding to the given EventFlags.
+  xkb_mod_mask_t EventFlagsToXkbFlags(int ui_flags) const;
+
+  // Determines the XKB KeySym and character associated with a key.
+  // Returns true on success.
+  bool XkbLookup(xkb_keycode_t xkb_keycode,
+                 xkb_mod_mask_t xkb_flags,
+                 xkb_keysym_t* xkb_keysym,
+                 base::char16* character) const;
+
+  // Maps DomCode to xkb_keycode_t.
+  const XkbKeyCodeConverter& key_code_converter_;
+
+  // libxkbcommon uses explicit reference counting for its structures,
+  // so we need to trigger its cleanup.
+  struct XkbContextDeleter {
+    void operator()(xkb_context* context) { xkb_context_unref(context); }
+  };
+  scoped_ptr<xkb_context, XkbContextDeleter> xkb_context_;
+  struct XkbstateDeleter {
+    void operator()(xkb_state* state) { xkb_state_unref(state); }
+  };
+  scoped_ptr<xkb_state, XkbstateDeleter> xkb_state_;
+
+  // Table for EventFlagsToXkbFlags().
+  struct XkbFlagMapEntry {
+    int ui_flag;
+    xkb_mod_mask_t xkb_flag;
+  };
+  std::vector<XkbFlagMapEntry> xkb_flag_map_;
+};
+
+}  // namespace ui
+
+#endif  // UI_EVENTS_OZONE_LAYOUT_XKB_XKB_KEYBOARD_LAYOUT_ENGINE_H_