InputManager/AcceleratorManager for athena

InputManager provides ToplevelEventTarget and AcceleratorManager.

Added test short cut (ctrl-l) to show the home card.

BUG=375534
TEST=covered by unit tests
R=sadrul@chromium.org, sky@chromium.org

Review URL: https://codereview.chromium.org/305873002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@275545 0039d316-1c4b-4281-b951-d872f2087c98

13 files changed, 677 insertions, 1 deletions

diff --git a/athena/athena.gyp b/athena/athena.gyp
index c7adae5..6fdb64c 100644
--- a/athena/athena.gyp
+++ b/athena/athena.gyp
@@ -36,6 +36,11 @@
         'home/app_list_view_delegate.h',
         'home/home_card_impl.cc',
         'home/public/home_card.h',
+	'input/public/input_manager.h',
+	'input/public/accelerator_manager.h',
+	'input/input_manager_impl.cc',
+	'input/accelerator_manager_impl.cc',
+	'input/accelerator_manager_impl.h',
         'screen/background_controller.cc',
         'screen/background_controller.h',
         'screen/public/screen_manager.h',
@@ -104,6 +109,7 @@
       ],
       'sources': [
         'test/athena_unittests.cc',
+        'input/accelerator_manager_unittest.cc',
         'wm/window_manager_unittest.cc',
       ],
     }
diff --git a/athena/home/DEPS b/athena/home/DEPS
index 660f468..3c13d2d 100644
--- a/athena/home/DEPS
+++ b/athena/home/DEPS
@@ -1,4 +1,5 @@
 include_rules = [
+  "+athena/input/public",
   "+athena/screen/public",
   "+third_party/skia/include",
   "+ui/aura",
diff --git a/athena/home/home_card_impl.cc b/athena/home/home_card_impl.cc
index 13723af..949d551 100644
--- a/athena/home/home_card_impl.cc
+++ b/athena/home/home_card_impl.cc
@@ -5,6 +5,8 @@
 #include "athena/home/public/home_card.h"
 
 #include "athena/home/app_list_view_delegate.h"
+#include "athena/input/public/accelerator_manager.h"
+#include "athena/input/public/input_manager.h"
 #include "athena/screen/public/screen_manager.h"
 #include "ui/app_list/pagination_model.h"
 #include "ui/app_list/views/app_list_view.h"
@@ -68,7 +70,7 @@ class HomeCardLayoutManager : public aura::LayoutManager {
   DISALLOW_COPY_AND_ASSIGN(HomeCardLayoutManager);
 };
 
-class HomeCardImpl : public HomeCard {
+class HomeCardImpl : public HomeCard, public AcceleratorHandler {
  public:
   HomeCardImpl();
   virtual ~HomeCardImpl();
@@ -76,6 +78,20 @@ class HomeCardImpl : public HomeCard {
   void Init();
 
  private:
+  enum Command {
+    COMMAND_SHOW_HOME_CARD,
+  };
+  void InstallAccelerators();
+
+  // AcceleratorHandler:
+  virtual bool IsCommandEnabled(int command_id) const OVERRIDE { return true; }
+  virtual bool OnAcceleratorFired(int command_id,
+                                  const ui::Accelerator& accelerator) OVERRIDE {
+    DCHECK_EQ(COMMAND_SHOW_HOME_CARD, command_id);
+    home_card_widget_->Show();
+    return true;
+  }
+
   views::Widget* home_card_widget_;
 
   DISALLOW_COPY_AND_ASSIGN(HomeCardImpl);
@@ -94,6 +110,8 @@ HomeCardImpl::~HomeCardImpl() {
 }
 
 void HomeCardImpl::Init() {
+  InstallAccelerators();
+
   aura::Window* container =
       ScreenManager::Get()->CreateContainer("HomeCardContainer");
   container->SetLayoutManager(new HomeCardLayoutManager(container));
@@ -111,6 +129,15 @@ void HomeCardImpl::Init() {
   view->ShowWhenReady();
 }
 
+void HomeCardImpl::InstallAccelerators() {
+  const AcceleratorData accelerator_data[] = {
+      {TRIGGER_ON_PRESS, ui::VKEY_L, ui::EF_CONTROL_DOWN,
+       COMMAND_SHOW_HOME_CARD, AF_NONE},
+  };
+  InputManager::Get()->GetAcceleratorManager()->RegisterAccelerators(
+      accelerator_data, arraysize(accelerator_data), this);
+}
+
 }  // namespace
 
 // static
diff --git a/athena/input/DEPS b/athena/input/DEPS
new file mode 100644
index 0000000..5b66b22
--- /dev/null
+++ b/athena/input/DEPS
@@ -0,0 +1,13 @@
+include_rules = [
+  "+ui/aura",
+  "+ui/base",
+  "+ui/events",
+  "+ui/wm/core",
+  "+ui/wm/public",
+]
+
+specific_include_rules = {
+  ".*unittest\.cc": [
+    "+athena/test",
+  ],
+}
diff --git a/athena/input/accelerator_manager_impl.cc b/athena/input/accelerator_manager_impl.cc
new file mode 100644
index 0000000..cdd4673
--- /dev/null
+++ b/athena/input/accelerator_manager_impl.cc
@@ -0,0 +1,190 @@
+// 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.
+
+#include "athena/input/accelerator_manager_impl.h"
+
+#include "athena/input/public/input_manager.h"
+#include "base/logging.h"
+#include "ui/aura/window.h"
+#include "ui/base/accelerators/accelerator_manager.h"
+#include "ui/events/event.h"
+#include "ui/events/event_target.h"
+#include "ui/wm/core/accelerator_delegate.h"
+#include "ui/wm/core/accelerator_filter.h"
+#include "ui/wm/core/nested_accelerator_controller.h"
+#include "ui/wm/core/nested_accelerator_delegate.h"
+#include "ui/wm/public/dispatcher_client.h"
+
+namespace athena {
+
+namespace {
+
+// Accelerators inside nested message loop are handled by
+// wm::NestedAcceleratorController while accelerators in normal case are
+// handled by wm::AcceleratorFilter. These delegates act bridges in these
+// two different environment so that AcceleratorManagerImpl can handle
+// accelerators in an uniform way.
+
+class NestedAcceleratorDelegate : public wm::NestedAcceleratorDelegate {
+ public:
+  explicit NestedAcceleratorDelegate(
+      AcceleratorManagerImpl* accelerator_manager)
+      : accelerator_manager_(accelerator_manager) {}
+  virtual ~NestedAcceleratorDelegate() {}
+
+ private:
+  // wm::NestedAcceleratorDelegate:
+  virtual Result ProcessAccelerator(
+      const ui::Accelerator& accelerator) OVERRIDE {
+    return accelerator_manager_->ProcessAccelerator(accelerator)
+               ? RESULT_PROCESSED
+               : RESULT_NOT_PROCESSED;
+  }
+
+  AcceleratorManagerImpl* accelerator_manager_;
+
+  DISALLOW_COPY_AND_ASSIGN(NestedAcceleratorDelegate);
+};
+
+class AcceleratorDelegate : public wm::AcceleratorDelegate {
+ public:
+  explicit AcceleratorDelegate(AcceleratorManagerImpl* accelerator_manager)
+      : accelerator_manager_(accelerator_manager) {}
+  virtual ~AcceleratorDelegate() {}
+
+ private:
+  // wm::AcceleratorDelegate:
+  virtual bool ProcessAccelerator(const ui::KeyEvent& event,
+                                  const ui::Accelerator& accelerator,
+                                  KeyType key_type) OVERRIDE {
+    aura::Window* target = static_cast<aura::Window*>(event.target());
+    if (!target->IsRootWindow() &&
+        !accelerator_manager_->IsReservedAccelerator(accelerator)) {
+      // TODO(oshima): do the same when the active window is in fullscreen.
+      return false;
+    }
+    return accelerator_manager_->ProcessAccelerator(accelerator);
+  }
+
+  AcceleratorManagerImpl* accelerator_manager_;
+  DISALLOW_COPY_AND_ASSIGN(AcceleratorDelegate);
+};
+
+}  // namespace
+
+class AcceleratorManagerImpl::InternalData {
+ public:
+  InternalData(int command_id, AcceleratorHandler* handler, int flags)
+      : command_id_(command_id), handler_(handler), flags_(flags) {}
+
+  bool IsNonAutoRepeatable() const { return flags_ & AF_NON_AUTO_REPEATABLE; }
+  bool IsDebug() const { return flags_ & AF_DEBUG; }
+  bool IsReserved() const { return flags_ & AF_RESERVED; }
+
+  bool IsCommandEnabled() const {
+    return handler_->IsCommandEnabled(command_id_);
+  }
+
+  bool OnAcceleratorFired(const ui::Accelerator& accelerator) {
+    return handler_->OnAcceleratorFired(command_id_, accelerator);
+  }
+
+ private:
+  int command_id_;
+  AcceleratorHandler* handler_;
+  int flags_;
+
+  // This class is copyable by design.
+};
+
+AcceleratorManagerImpl::AcceleratorManagerImpl()
+    : accelerator_manager_(new ui::AcceleratorManager) {
+}
+
+AcceleratorManagerImpl::~AcceleratorManagerImpl() {
+  nested_accelerator_controller_.reset();
+  accelerator_filter_.reset();
+}
+
+void AcceleratorManagerImpl::Init() {
+  ui::EventTarget* toplevel = InputManager::Get()->GetTopmostEventTarget();
+  nested_accelerator_controller_.reset(
+      new wm::NestedAcceleratorController(new NestedAcceleratorDelegate(this)));
+
+  scoped_ptr<wm::AcceleratorDelegate> accelerator_delegate(
+      new AcceleratorDelegate(this));
+
+  accelerator_filter_.reset(
+      new wm::AcceleratorFilter(accelerator_delegate.Pass()));
+  toplevel->AddPreTargetHandler(accelerator_filter_.get());
+}
+
+void AcceleratorManagerImpl::OnRootWindowCreated(aura::Window* root_window) {
+  aura::client::SetDispatcherClient(root_window,
+                                    nested_accelerator_controller_.get());
+}
+
+bool AcceleratorManagerImpl::IsReservedAccelerator(
+    const ui::Accelerator& accelerator) const {
+  std::map<ui::Accelerator, InternalData>::const_iterator iter =
+      accelerators_.find(accelerator);
+  if (iter == accelerators_.end())
+    return false;
+  return iter->second.IsReserved();
+}
+
+bool AcceleratorManagerImpl::ProcessAccelerator(
+    const ui::Accelerator& accelerator) {
+  return accelerator_manager_->Process(accelerator);
+}
+
+void AcceleratorManagerImpl::RegisterAccelerators(
+    const AcceleratorData accelerators[],
+    size_t num_accelerators,
+    AcceleratorHandler* handler) {
+  for (size_t i = 0; i < num_accelerators; ++i)
+    RegisterAccelerator(accelerators[i], handler);
+}
+
+void AcceleratorManagerImpl::EnableDebugAccelerators() {
+  debug_accelerators_enabled_ = true;
+}
+
+bool AcceleratorManagerImpl::AcceleratorPressed(
+    const ui::Accelerator& accelerator) {
+  std::map<ui::Accelerator, InternalData>::iterator iter =
+      accelerators_.find(accelerator);
+  DCHECK(iter != accelerators_.end());
+  if (iter == accelerators_.end())
+    return false;
+  InternalData& data = iter->second;
+  if (data.IsDebug() && !debug_accelerators_enabled_)
+    return false;
+  if (accelerator.IsRepeat() && data.IsNonAutoRepeatable())
+    return false;
+  return data.IsCommandEnabled() ? data.OnAcceleratorFired(accelerator) : false;
+}
+
+bool AcceleratorManagerImpl::CanHandleAccelerators() const {
+  return true;
+}
+
+void AcceleratorManagerImpl::RegisterAccelerator(
+    const AcceleratorData& accelerator_data,
+    AcceleratorHandler* handler) {
+  ui::Accelerator accelerator(accelerator_data.keycode,
+                              accelerator_data.keyevent_flags);
+  accelerator.set_type(accelerator_data.trigger_event == TRIGGER_ON_PRESS
+                           ? ui::ET_KEY_PRESSED
+                           : ui::ET_KEY_RELEASED);
+  accelerator_manager_->Register(
+      accelerator, ui::AcceleratorManager::kNormalPriority, this);
+  accelerators_.insert(
+      std::make_pair(accelerator,
+                     InternalData(accelerator_data.command_id,
+                                  handler,
+                                  accelerator_data.accelerator_flags)));
+}
+
+}  // namespace athena
diff --git a/athena/input/accelerator_manager_impl.h b/athena/input/accelerator_manager_impl.h
new file mode 100644
index 0000000..1a5e8a9
--- /dev/null
+++ b/athena/input/accelerator_manager_impl.h
@@ -0,0 +1,76 @@
+// 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 ATHENA_INPUT_ACCELERATOR_MANAGER_H_
+#define ATHENA_INPUT_ACCELERATOR_MANAGER_H_
+
+#include "athena/input/public/accelerator_manager.h"
+
+#include <map>
+
+#include "base/macros.h"
+#include "ui/base/accelerators/accelerator.h"
+#include "ui/events/event_target_iterator.h"
+
+namespace aura {
+class Window;
+}
+
+namespace ui {
+class AcceleratorManager;
+}
+
+namespace wm {
+class AcceleratorFilter;
+class NestedAcceleratorController;
+}
+
+namespace athena {
+
+// AcceleratorManagerImpl provides a API to register accelerators
+// for athena modules. It hides various details on accelerator handling
+// such as how to handle accelerator in a nested loop, reserved accelerators
+// and repeated accelerators.
+class AcceleratorManagerImpl : public AcceleratorManager,
+                               public ui::AcceleratorTarget {
+ public:
+  AcceleratorManagerImpl();
+  virtual ~AcceleratorManagerImpl();
+
+  void Init();
+
+  void OnRootWindowCreated(aura::Window* root_window);
+
+  bool IsReservedAccelerator(const ui::Accelerator& accelerator) const;
+  bool ProcessAccelerator(const ui::Accelerator& accelerator);
+
+ private:
+  // AcceleratorManager:
+  virtual void RegisterAccelerators(const AcceleratorData accelerators[],
+                                    size_t num_accelerators,
+                                    AcceleratorHandler* handler) OVERRIDE;
+  virtual void EnableDebugAccelerators() OVERRIDE;
+
+  // ui::AcceleratorTarget:
+  virtual bool AcceleratorPressed(const ui::Accelerator& accelerator) OVERRIDE;
+  virtual bool CanHandleAccelerators() const OVERRIDE;
+
+  class InternalData;
+
+  void RegisterAccelerator(const AcceleratorData& accelerator,
+                           AcceleratorHandler* handler);
+
+  bool debug_accelerators_enabled_;
+  std::map<ui::Accelerator, InternalData> accelerators_;
+  scoped_ptr<ui::AcceleratorManager> accelerator_manager_;
+
+  scoped_ptr<wm::AcceleratorFilter> accelerator_filter_;
+  scoped_ptr<wm::NestedAcceleratorController> nested_accelerator_controller_;
+
+  DISALLOW_COPY_AND_ASSIGN(AcceleratorManagerImpl);
+};
+
+}  // namespace athena
+
+#endif  // ATHENA_INPUT_ACCELERATOR_MANAGER_H_
diff --git a/athena/input/accelerator_manager_unittest.cc b/athena/input/accelerator_manager_unittest.cc
new file mode 100644
index 0000000..cd80e86
--- /dev/null
+++ b/athena/input/accelerator_manager_unittest.cc
@@ -0,0 +1,120 @@
+// 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.
+
+#include "athena/input/public/accelerator_manager.h"
+
+#include "athena/input/public/input_manager.h"
+#include "athena/test/athena_test_base.h"
+#include "ui/aura/test/event_generator.h"
+
+namespace athena {
+namespace {
+
+const int kInvalidCommandId = -1;
+
+class TestHandler : public AcceleratorHandler {
+ public:
+  TestHandler() : fired_command_id_(kInvalidCommandId), enabled_(true) {}
+  virtual ~TestHandler() {}
+
+  void set_enabled(bool enabled) { enabled_ = enabled; }
+
+  int GetFiredCommandIdAndReset() {
+    int fired = fired_command_id_;
+    fired_command_id_ = kInvalidCommandId;
+    return fired;
+  }
+
+ private:
+  // AcceleratorHandler:
+  virtual bool IsCommandEnabled(int command_id) const OVERRIDE {
+    return enabled_;
+  }
+  virtual bool OnAcceleratorFired(int command_id,
+                                  const ui::Accelerator& accelerator) OVERRIDE {
+    fired_command_id_ = command_id;
+    return true;
+  }
+
+  int fired_command_id_;
+  bool enabled_;
+
+  DISALLOW_COPY_AND_ASSIGN(TestHandler);
+};
+
+}  // namespace athena
+
+typedef test::AthenaTestBase InputManagerTest;
+
+TEST_F(InputManagerTest, Basic) {
+  enum TestCommandId {
+    COMMAND_A,
+    COMMAND_B,
+    COMMAND_C,
+    COMMAND_D,
+    COMMAND_E,
+  };
+  const AcceleratorData data[] = {
+      {TRIGGER_ON_PRESS, ui::VKEY_A, ui::EF_SHIFT_DOWN, COMMAND_A, AF_RESERVED},
+      {TRIGGER_ON_RELEASE, ui::VKEY_B, ui::EF_SHIFT_DOWN, COMMAND_B,
+       AF_RESERVED},
+      {TRIGGER_ON_PRESS, ui::VKEY_C, ui::EF_SHIFT_DOWN, COMMAND_C,
+       AF_RESERVED | AF_DEBUG},
+      {TRIGGER_ON_PRESS, ui::VKEY_D, ui::EF_SHIFT_DOWN, COMMAND_D,
+       AF_RESERVED | AF_NON_AUTO_REPEATABLE},
+      {TRIGGER_ON_PRESS, ui::VKEY_E, ui::EF_SHIFT_DOWN, COMMAND_E, AF_NONE},
+  };
+  AcceleratorManager* accelerator_manager =
+      InputManager::Get()->GetAcceleratorManager();
+  TestHandler test_handler;
+  accelerator_manager->RegisterAccelerators(
+      data, arraysize(data), &test_handler);
+
+  aura::test::EventGenerator generator(root_window());
+  generator.PressKey(ui::VKEY_A, ui::EF_NONE);
+  EXPECT_EQ(kInvalidCommandId, test_handler.GetFiredCommandIdAndReset());
+
+  // Trigger on press.
+  generator.PressKey(ui::VKEY_A, ui::EF_SHIFT_DOWN);
+  EXPECT_EQ(COMMAND_A, test_handler.GetFiredCommandIdAndReset());
+  generator.ReleaseKey(ui::VKEY_A, ui::EF_SHIFT_DOWN);
+  EXPECT_EQ(kInvalidCommandId, test_handler.GetFiredCommandIdAndReset());
+
+  // Trigger on release.
+  generator.PressKey(ui::VKEY_B, ui::EF_SHIFT_DOWN);
+  EXPECT_EQ(kInvalidCommandId, test_handler.GetFiredCommandIdAndReset());
+  generator.ReleaseKey(ui::VKEY_B, ui::EF_SHIFT_DOWN);
+  EXPECT_EQ(COMMAND_B, test_handler.GetFiredCommandIdAndReset());
+
+  // Disable command.
+  test_handler.set_enabled(false);
+  generator.PressKey(ui::VKEY_A, ui::EF_SHIFT_DOWN);
+  EXPECT_EQ(kInvalidCommandId, test_handler.GetFiredCommandIdAndReset());
+  test_handler.set_enabled(true);
+  generator.PressKey(ui::VKEY_A, ui::EF_SHIFT_DOWN);
+  EXPECT_EQ(COMMAND_A, test_handler.GetFiredCommandIdAndReset());
+
+  // Debug accelerators.
+  generator.PressKey(ui::VKEY_C, ui::EF_SHIFT_DOWN);
+  EXPECT_EQ(kInvalidCommandId, test_handler.GetFiredCommandIdAndReset());
+
+  accelerator_manager->EnableDebugAccelerators();
+  generator.PressKey(ui::VKEY_C, ui::EF_SHIFT_DOWN);
+  EXPECT_EQ(COMMAND_C, test_handler.GetFiredCommandIdAndReset());
+
+  // Non auto repeatable
+  generator.PressKey(ui::VKEY_D, ui::EF_SHIFT_DOWN);
+  EXPECT_EQ(COMMAND_D, test_handler.GetFiredCommandIdAndReset());
+  generator.PressKey(ui::VKEY_D, ui::EF_SHIFT_DOWN | ui::EF_IS_REPEAT);
+  EXPECT_EQ(kInvalidCommandId, test_handler.GetFiredCommandIdAndReset());
+
+  // Non reserved accelerator won't be handled unless there is
+  // a view's focus manager.
+  // TODO(oshima): Support view's focus manager. Investigate we can implement
+  // the non reserved behavior without view's focus manager.
+  generator.PressKey(ui::VKEY_E, ui::EF_SHIFT_DOWN);
+  EXPECT_EQ(kInvalidCommandId, test_handler.GetFiredCommandIdAndReset());
+}
+
+}  // namespace athena
diff --git a/athena/input/input_manager_impl.cc b/athena/input/input_manager_impl.cc
new file mode 100644
index 0000000..3d1c803
--- /dev/null
+++ b/athena/input/input_manager_impl.cc
@@ -0,0 +1,122 @@
+// 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.
+
+#include "athena/input/public/input_manager.h"
+
+#include "athena/input/accelerator_manager_impl.h"
+#include "base/logging.h"
+#include "ui/aura/client/event_client.h"
+#include "ui/aura/env.h"
+#include "ui/events/event_target.h"
+
+namespace athena {
+namespace {
+
+InputManager* instance = NULL;
+
+class InputManagerImpl : public InputManager,
+                         public ui::EventTarget,
+                         public aura::client::EventClient {
+ public:
+  InputManagerImpl();
+  virtual ~InputManagerImpl();
+
+  void Init();
+  void Shutdown();
+
+ private:
+  // InputManager:
+  virtual void OnRootWindowCreated(aura::Window* root_window) OVERRIDE;
+  virtual ui::EventTarget* GetTopmostEventTarget() OVERRIDE { return this; }
+  virtual AcceleratorManager* GetAcceleratorManager() OVERRIDE {
+    return accelerator_manager_.get();
+  }
+
+  // Overridden from aura::client::EventClient:
+  virtual bool CanProcessEventsWithinSubtree(
+      const aura::Window* window) const OVERRIDE {
+    return true;
+  }
+  virtual ui::EventTarget* GetToplevelEventTarget() OVERRIDE { return this; }
+
+  // ui::EventTarget:
+  virtual bool CanAcceptEvent(const ui::Event& event) OVERRIDE;
+  virtual ui::EventTarget* GetParentTarget() OVERRIDE;
+  virtual scoped_ptr<ui::EventTargetIterator> GetChildIterator() const OVERRIDE;
+  virtual ui::EventTargeter* GetEventTargeter() OVERRIDE;
+  virtual void OnEvent(ui::Event* event) OVERRIDE;
+
+  scoped_ptr<AcceleratorManagerImpl> accelerator_manager_;
+
+  DISALLOW_COPY_AND_ASSIGN(InputManagerImpl);
+};
+
+InputManagerImpl::InputManagerImpl()
+    : accelerator_manager_(new AcceleratorManagerImpl) {
+  DCHECK(!instance);
+  instance = this;
+}
+
+InputManagerImpl::~InputManagerImpl() {
+  DCHECK_EQ(instance, this);
+  Shutdown();
+  instance = NULL;
+}
+
+void InputManagerImpl::Init() {
+  accelerator_manager_->Init();
+}
+
+void InputManagerImpl::Shutdown() {
+  accelerator_manager_.reset();
+}
+
+void InputManagerImpl::OnRootWindowCreated(aura::Window* root_window) {
+  aura::client::SetEventClient(root_window, this);
+  accelerator_manager_->OnRootWindowCreated(root_window);
+}
+
+bool InputManagerImpl::CanAcceptEvent(const ui::Event& event) {
+  return true;
+}
+
+ui::EventTarget* InputManagerImpl::GetParentTarget() {
+  return aura::Env::GetInstance();
+}
+
+scoped_ptr<ui::EventTargetIterator> InputManagerImpl::GetChildIterator() const {
+  return scoped_ptr<ui::EventTargetIterator>();
+}
+
+ui::EventTargeter* InputManagerImpl::GetEventTargeter() {
+  NOTREACHED();
+  return NULL;
+}
+
+void InputManagerImpl::OnEvent(ui::Event* event) {
+}
+
+}  // namespace
+
+// static
+InputManager* InputManager::Create() {
+  (new InputManagerImpl)->Init();
+  DCHECK(instance);
+  return instance;
+}
+
+// static
+InputManager* InputManager::Get() {
+  DCHECK(instance);
+  return instance;
+}
+
+// static
+void InputManager::Shutdown() {
+  DCHECK(instance);
+  delete instance;
+  DCHECK(!instance);
+}
+
+}  // namespace athena
diff --git a/athena/input/public/DEPS b/athena/input/public/DEPS
new file mode 100644
index 0000000..941cfac
--- /dev/null
+++ b/athena/input/public/DEPS
@@ -0,0 +1,4 @@
+include_rules = [
+  "-athena/input",
+  "+athena/athena_export.h",
+]
diff --git a/athena/input/public/accelerator_manager.h b/athena/input/public/accelerator_manager.h
new file mode 100644
index 0000000..e0a1ad4
--- /dev/null
+++ b/athena/input/public/accelerator_manager.h
@@ -0,0 +1,72 @@
+// 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 ATHENA_INPUT_PUBLIC_ACCELERATOR_MANAGER_H_
+#define ATHENA_INPUT_PUBLIC_ACCELERATOR_MANAGER_H_
+
+#include "athena/athena_export.h"
+#include "ui/events/keycodes/keyboard_codes.h"
+
+namespace ui {
+class Accelerator;
+}
+
+namespace athena {
+
+enum TriggerEvent {
+  TRIGGER_ON_PRESS,
+  TRIGGER_ON_RELEASE,
+};
+
+// Accelerator flags.
+enum AcceleratorFlags {
+  AF_NONE = 0,
+  // Used for accelerators that should not be fired on auto repeated
+  // key event, such as toggling fullscrren.
+  AF_NON_AUTO_REPEATABLE = 1 << 0,
+  // Most key events are sent to applications first as they may
+  // want to consume them. Reserverd accelerators are reserved for OS
+  // and cannot be consumed by apps. (such as window cycling)
+  AF_RESERVED = 1 << 1,
+  // Used for accelerators that are useful only in debug mode.
+  AF_DEBUG = 1 << 2,
+};
+
+struct AcceleratorData {
+  // true if the accelerator should be triggered upon ui::ET_KEY_PRESSED
+  TriggerEvent trigger_event;
+  ui::KeyboardCode keycode;  // KeyEvent event flags.
+  int keyevent_flags;        // Combination of ui::KeyEventFlags
+  int command_id;            // ID to distinguish
+  int accelerator_flags;     // Combination of AcceleratorFlags;
+};
+
+// An interface that implements behavior for the set of
+// accelerators.
+class ATHENA_EXPORT AcceleratorHandler {
+ public:
+  virtual ~AcceleratorHandler() {}
+
+  virtual bool IsCommandEnabled(int command_id) const = 0;
+  virtual bool OnAcceleratorFired(int command_id,
+                                  const ui::Accelerator& accelerator) = 0;
+};
+
+class AcceleratorManager {
+ public:
+  virtual ~AcceleratorManager() {}
+
+  // Register accelerators and its handler that will be invoked when
+  // one of accelerator is fired.
+  virtual void RegisterAccelerators(const AcceleratorData accelerators[],
+                                    size_t num_accelerators,
+                                    AcceleratorHandler* handler) = 0;
+
+  // Enables accelerators that has a AF_DEBUG flag.
+  virtual void EnableDebugAccelerators() = 0;
+};
+
+}  // namespace athena
+
+#endif  // ATHENA_INPUT_PUBLIC_ACCELERATOR_MANAGER_H_
diff --git a/athena/input/public/input_manager.h b/athena/input/public/input_manager.h
new file mode 100644
index 0000000..cc70175
--- /dev/null
+++ b/athena/input/public/input_manager.h
@@ -0,0 +1,41 @@
+// 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 ATHENA_INPUT_PUBLIC_INPUT_MANAGER_H_
+#define ATHENA_INPUT_PUBLIC_INPUT_MANAGER_H_
+
+#include "athena/athena_export.h"
+
+namespace aura {
+class Window;
+}
+
+namespace ui {
+class EventTarget;
+}
+
+namespace athena {
+class AcceleratorManager;
+
+class ATHENA_EXPORT InputManager {
+ public:
+  // Creates and deletes the singleton object of the InputManager
+  // implementation.
+  static InputManager* Create();
+  static InputManager* Get();
+  static void Shutdown();
+
+  // TODO(oshima): Fix the initialization process and replace this
+  // with EnvObserver::WindowInitialized
+  virtual void OnRootWindowCreated(aura::Window* root_window) = 0;
+
+  virtual ui::EventTarget* GetTopmostEventTarget() = 0;
+  virtual AcceleratorManager* GetAcceleratorManager() = 0;
+
+  virtual ~InputManager() {}
+};
+
+}  // namespace athena
+
+#endif  // ATHENA_INPUT_PUBLIC_INPUT_MANAGER_H_
diff --git a/athena/main/DEPS b/athena/main/DEPS
index 9d9de5a..2f77e06 100644
--- a/athena/main/DEPS
+++ b/athena/main/DEPS
@@ -2,6 +2,7 @@ include_rules = [
   "+athena/activity/public",
   "+athena/content/public",
   "+athena/home/public",
+  "+athena/input/public",
   "+athena/screen/public",
   "+athena/task/public",
   "+athena/wm/public",
diff --git a/athena/main/athena_launcher.cc b/athena/main/athena_launcher.cc
index 89e8452..6faa396 100644
--- a/athena/main/athena_launcher.cc
+++ b/athena/main/athena_launcher.cc
@@ -7,6 +7,7 @@
 #include "athena/activity/public/activity_factory.h"
 #include "athena/activity/public/activity_manager.h"
 #include "athena/home/public/home_card.h"
+#include "athena/input/public/input_manager.h"
 #include "athena/main/placeholder.h"
 #include "athena/screen/public/screen_manager.h"
 #include "athena/wm/public/window_manager.h"
@@ -47,6 +48,7 @@ void StartAthena(aura::Window* root_window,
   aura::client::SetVisibilityClient(root_window,
                                     root_window_state->visibility_client.get());
 
+  athena::InputManager::Create()->OnRootWindowCreated(root_window);
   athena::ScreenManager::Create(root_window);
   athena::WindowManager::Create();
   athena::HomeCard::Create();
@@ -61,6 +63,7 @@ void ShutdownAthena() {
   athena::HomeCard::Shutdown();
   athena::WindowManager::Shutdown();
   athena::ScreenManager::Shutdown();
+  athena::InputManager::Shutdown();
 }
 
 }  // namespace athena