Keyboard Lock Host implementation

components/keyboard_lock/active_key_event_filter_registrar.h

+// Copyright 2017 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 COMPONENTS_KEYBOARD_LOCK_ACTIVE_KEY_EVENT_FILTER_REGISTRAR_H_
+#define COMPONENTS_KEYBOARD_LOCK_ACTIVE_KEY_EVENT_FILTER_REGISTRAR_H_
+
+#include <memory>
+
+#include "components/keyboard_lock/key_event_filter.h"
+#include "components/keyboard_lock/key_hook_activator.h"
+
+namespace keyboard_lock {
+
+class ActiveKeyEventFilterTracker;
+
+// An implementation of KeyHookActivator to forward requests to |key_hook| and
+// register / unregister cooresponding key event filter |filter| to |tracker|.
+class ActiveKeyEventFilterRegistrar final : public KeyHookActivator {
+ public:
+  // |tracker| should outlive |this|.
+  ActiveKeyEventFilterRegistrar(ActiveKeyEventFilterTracker* tracker,
+                                std::unique_ptr<KeyHookActivator> key_hook,
+                                KeyEventFilter* filter);
+  ~ActiveKeyEventFilterRegistrar() override;
+
+ private:
+  // KeyHookActivator implementations
+  void RegisterKey(const std::vector<ui::KeyboardCode>& codes,
+                   base::Callback<void(bool)> on_result) override;
+  void UnregisterKey(const std::vector<ui::KeyboardCode>& codes,
+                     base::Callback<void(bool)> on_result) override;
+  void Activate(base::Callback<void(bool)> on_result) override;
+  void Deactivate(base::Callback<void(bool)> on_result) override;
+
+  ActiveKeyEventFilterTracker* const tracker_;
+  std::unique_ptr<KeyHookActivator> key_hook_;
+  KeyEventFilter* const filter_;
+};
+
+}  // namespace keyboard_lock
+
+#endif  // COMPONENTS_KEYBOARD_LOCK_ACTIVE_KEY_EVENT_FILTER_REGISTRAR_H_