MD Settings: First half of Device > Keyboard sub-page.

chrome/browser/ui/webui/settings/chromeos/device_keyboard_handler.h

+// Copyright 2016 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 CHROME_BROWSER_UI_WEBUI_SETTINGS_CHROMEOS_DEVICE_KEYBOARD_HANDLER_H_
+#define CHROME_BROWSER_UI_WEBUI_SETTINGS_CHROMEOS_DEVICE_KEYBOARD_HANDLER_H_
+
+#include "base/macros.h"
+#include "chrome/browser/ui/webui/settings/md_settings_ui.h"
+#include "ui/events/devices/input_device_event_observer.h"
+
+namespace base {
+class ListValue;
+}
+
+namespace content {
+class WebUI;
+}
+
+class Profile;
+
+namespace chromeos {
+namespace settings {
+
+// Chrome OS "Keyboard" settings page UI handler.
+class KeyboardHandler
+    : public ::settings::SettingsPageUIHandler,
+      public ui::InputDeviceEventObserver {
+ public:
+  explicit KeyboardHandler(content::WebUI* webui);
+  ~KeyboardHandler() override;
+
+  // SettingsPageUIHandler implementation.
+  void RegisterMessages() override;
+
+  // ui::InputDeviceEventObserver implementation.
+  void OnKeyboardDeviceConfigurationChanged() override;
+
+ private:
+  // Initializes the page with the current keyboard information.
+  void HandleInitialize(const base::ListValue* args);
+
+  // Shows or hides the Caps Lock and Diamond key settings based on whether the
+  // system status.
+  void UpdateShowKeys() const;
+
+  Profile* profile_;  // Weak pointer.
+
+  DISALLOW_COPY_AND_ASSIGN(KeyboardHandler);
+};
+
+}  // namespace settings
+}  // namespace chromeos
+
+#endif  // CHROME_BROWSER_UI_WEBUI_SETTINGS_CHROMEOS_DEVICE_KEYBOARD_HANDLER_H_