Adds the UserInputMonitor implementation for Windows.

media/base/user_input_monitor_win.cc

 // Copyright 2013 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 "media/base/user_input_monitor.h"
 
+#include "base/bind.h"
+#include "base/location.h"
+#include "base/logging.h"
+#include "base/memory/weak_ptr.h"
+#include "base/observer_list_threadsafe.h"
+#include "base/single_thread_task_runner.h"
+#include "base/strings/stringprintf.h"
+#include "base/synchronization/lock.h"
+#include "base/win/message_window.h"
+#include "media/base/keyboard_event_counter.h"
+#include "third_party/skia/include/core/SkPoint.h"
+#include "ui/base/keycodes/keyboard_code_conversion_win.h"
+
 namespace media {
-
-// TODO(jiayl): add the implementation.
+namespace {
+
+// From the HID Usage Tables specification.
+const USHORT kGenericDesktopPage = 1;
+const USHORT kMouseUsage = 2;
+const USHORT kKeyboardUsage = 6;
+
+class UserInputMonitorWin : public UserInputMonitor {
+ public:
+  explicit UserInputMonitorWin(
+      const scoped_refptr<base::SingleThreadTaskRunner>& ui_task_runner);
+  virtual ~UserInputMonitorWin();
+
+  // Public interface of UserInputMonitor.
+  virtual void AddMouseListener(MouseEventListener* listener) OVERRIDE;
+  virtual void RemoveMouseListener(MouseEventListener* listener) OVERRIDE;
+  virtual size_t GetKeyPressCount() const OVERRIDE;
+
+ private:
+  // Private interface of UserInputMonitor.

[Sergey Ulanov, 2013/09/10 18:28:39]

nit: It's more common to say something like "UserInputMonitor overrides".
UserInputMonitor is not an interface, so this comment may be confusing.

[jiayl, 2013/09/10 18:34:15]

Done.

+  virtual void StartKeyboardMonitoring() OVERRIDE;
+  virtual void StopKeyboardMonitoring() OVERRIDE;
+
+  class Core;

[Sergey Ulanov, 2013/09/10 18:28:39]

nit: class declaration should be before the methods.

[jiayl, 2013/09/10 18:34:15]

Done.

+  Core* core_;
+
+  DISALLOW_COPY_AND_ASSIGN(UserInputMonitorWin);
+};
+
+// This is the actual implementation of event monitoring. It's separated from
+// UserInputMonitorWin since it needs to be deleted on the UI thread.
+class UserInputMonitorWin::Core {
+ public:
+  explicit Core(scoped_refptr<base::SingleThreadTaskRunner> ui_task_runner);
+  ~Core();
+
+  void AddMouseListener(MouseEventListener* listener);
+  void RemoveMouseListener(MouseEventListener* listener);
+  size_t GetKeyPressCount() const;
+  void StartKeyboardMonitoring();
+  void StopKeyboardMonitoring();
+  scoped_refptr<base::SingleThreadTaskRunner> ui_task_runner() {
+    return ui_task_runner_;
+  }
+
+ private:
+  enum EventBitMask {
+    MOUSE_EVENT_MASK = 1,
+    KEYBOARD_EVENT_MASK = 2,
+  };
+
+  void StartMonitor(EventBitMask type);
+  void StopMonitor(EventBitMask type);
+
+  // Handles WM_INPUT messages.
+  LRESULT OnInput(HRAWINPUT input_handle);
+  // Handles messages received by |window_|.
+  bool HandleMessage(UINT message,
+                     WPARAM wparam,
+                     LPARAM lparam,
+                     LRESULT* result);
+  RAWINPUTDEVICE* GetRawInputDevices(EventBitMask event, DWORD flags);
+
+  // Task runner on which |window_| is created.
+  base::Lock lock_;
+  scoped_refptr<base::SingleThreadTaskRunner> ui_task_runner_;
+  scoped_refptr<ObserverListThreadSafe<MouseEventListener> > mouse_listeners_;
+  size_t mouse_listeners_count_;
+
+  // These members are only accessed on the UI thread.
+  scoped_ptr<base::win::MessageWindow> window_;
+  uint8 events_monitored_;
+  KeyboardEventCounter counter_;
+  base::WeakPtrFactory<Core> weak_factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(Core);
+};
+
+UserInputMonitorWin::Core::Core(
+    scoped_refptr<base::SingleThreadTaskRunner> ui_task_runner)
+    : ui_task_runner_(ui_task_runner),
+      events_monitored_(0),
+      weak_factory_(this) {}
+
+UserInputMonitorWin::Core::~Core() {
+  DCHECK(!window_);
+  DCHECK(!events_monitored_);
+}
+
+void UserInputMonitorWin::Core::AddMouseListener(MouseEventListener* listener) {
+  mouse_listeners_->AddObserver(listener);
+  {
+    base::AutoLock auto_lock(lock_);
+    mouse_listeners_count_++;
+    if (mouse_listeners_count_ == 1) {
+      ui_task_runner_->PostTask(FROM_HERE,
+                                base::Bind(&Core::StartMonitor,
+                                           weak_factory_.GetWeakPtr(),
+                                           MOUSE_EVENT_MASK));
+      DVLOG(2) << "Started mouse monitoring.";
+    }
+  }
+}
+
+void UserInputMonitorWin::Core::RemoveMouseListener(
+    MouseEventListener* listener) {
+  mouse_listeners_->RemoveObserver(listener);
+  {
+    base::AutoLock auto_lock(lock_);
+    mouse_listeners_count_--;
+    if (mouse_listeners_count_ == 0) {
+      ui_task_runner_->PostTask(FROM_HERE,
+                                base::Bind(&Core::StopMonitor,
+                                           weak_factory_.GetWeakPtr(),
+                                           MOUSE_EVENT_MASK));
+      DVLOG(2) << "Stopped mouse monitoring.";
+    }
+  }
+}
+
+size_t UserInputMonitorWin::Core::GetKeyPressCount() const {
+  return counter_.GetKeyPressCount();
+}
+
+void UserInputMonitorWin::Core::StartKeyboardMonitoring() {
+  ui_task_runner_->PostTask(FROM_HERE,
+                            base::Bind(&Core::StartMonitor,
+                                       weak_factory_.GetWeakPtr(),
+                                       KEYBOARD_EVENT_MASK));
+}
+
+void UserInputMonitorWin::Core::StopKeyboardMonitoring() {
+  ui_task_runner_->PostTask(
+      FROM_HERE,
+      base::Bind(
+          &Core::StopMonitor, weak_factory_.GetWeakPtr(), KEYBOARD_EVENT_MASK));
+}
+
+void UserInputMonitorWin::Core::StartMonitor(EventBitMask type) {
+  DCHECK(ui_task_runner_->BelongsToCurrentThread());
+
+  if (events_monitored_ & type)
+    return;
+
+  if (type == KEYBOARD_EVENT_MASK)
+    counter_.Reset();
+
+  if (!window_) {
+    window_.reset(new base::win::MessageWindow());
+    if (!window_->Create(
+             base::Bind(&Core::HandleMessage, base::Unretained(this)))) {
+      LOG_GETLASTERROR(ERROR) << "Failed to create the raw input window";
+      window_.reset();
+      return;
+    }
+  }
+
+  // Register to receive raw mouse and/or keyboard input.
+  scoped_ptr<RAWINPUTDEVICE> device(GetRawInputDevices(type, RIDEV_INPUTSINK));
+  if (!RegisterRawInputDevices(device.get(), 1, sizeof(*device))) {
+    LOG_GETLASTERROR(ERROR)
+        << "RegisterRawInputDevices() failed for RIDEV_INPUTSINK";
+    return;
+  }
+  events_monitored_ |= type;
+}
+
+void UserInputMonitorWin::Core::StopMonitor(EventBitMask type) {
+  DCHECK(ui_task_runner_->BelongsToCurrentThread());
+
+  if (!(events_monitored_ & type))
+    return;
+
+  // Stop receiving raw input.
+  DCHECK(window_);
+  scoped_ptr<RAWINPUTDEVICE> device(GetRawInputDevices(type, RIDEV_REMOVE));
+
+  if (!RegisterRawInputDevices(device.get(), 1, sizeof(*device))) {
+    LOG_GETLASTERROR(INFO)
+        << "RegisterRawInputDevices() failed for RIDEV_REMOVE";
+  }
+
+  events_monitored_ &= ~type;
+  if (events_monitored_ == 0)
+    window_.reset();
+}
+
+LRESULT UserInputMonitorWin::Core::OnInput(HRAWINPUT input_handle) {
+  DCHECK(ui_task_runner_->BelongsToCurrentThread());
+
+  // Get the size of the input record.
+  UINT size = 0;
+  UINT result = GetRawInputData(
+      input_handle, RID_INPUT, NULL, &size, sizeof(RAWINPUTHEADER));
+  if (result == -1) {
+    LOG_GETLASTERROR(ERROR) << "GetRawInputData() failed";
+    return 0;
+  }
+  DCHECK_EQ(0u, result);
+
+  // Retrieve the input record itself.
+  scoped_ptr<uint8[]> buffer(new uint8[size]);
+  RAWINPUT* input = reinterpret_cast<RAWINPUT*>(buffer.get());
+  result = GetRawInputData(
+      input_handle, RID_INPUT, buffer.get(), &size, sizeof(RAWINPUTHEADER));
+  if (result == -1) {
+    LOG_GETLASTERROR(ERROR) << "GetRawInputData() failed";
+    return 0;
+  }
+  DCHECK_EQ(size, result);
+
+  // Notify the observer about events generated locally.
+  if (input->header.dwType == RIM_TYPEMOUSE && input->header.hDevice != NULL) {
+    POINT position;
+    if (!GetCursorPos(&position)) {
+      position.x = 0;
+      position.y = 0;
+    }
+    mouse_listeners_->Notify(&MouseEventListener::OnMouseMoved,
+                             SkIPoint::Make(position.x, position.y));
+  } else if (input->header.dwType == RIM_TYPEKEYBOARD &&
+             input->header.hDevice != NULL) {
+    ui::EventType event = (input->data.keyboard.Flags & RI_KEY_BREAK)
+                              ? ui::ET_KEY_RELEASED

[Sergey Ulanov, 2013/09/10 18:28:39]

nit: Operators normally should not be wrapped, i.e. ? should be on the previous
line. Ignore me if you used clang-format to format this code.

+                              : ui::ET_KEY_PRESSED;
+    ui::KeyboardCode key_code =
+        ui::KeyboardCodeForWindowsKeyCode(input->data.keyboard.VKey);
+    counter_.OnKeyboardEvent(event, key_code);
+  }
+
+  return DefRawInputProc(&input, 1, sizeof(RAWINPUTHEADER));
+}
+
+bool UserInputMonitorWin::Core::HandleMessage(UINT message,
+                                              WPARAM wparam,
+                                              LPARAM lparam,
+                                              LRESULT* result) {
+  DCHECK(ui_task_runner_->BelongsToCurrentThread());
+
+  switch (message) {
+    case WM_INPUT:
+      *result = OnInput(reinterpret_cast<HRAWINPUT>(lparam));
+      return true;
+
+    default:
+      return false;
+  }
+}
+
+RAWINPUTDEVICE* UserInputMonitorWin::Core::GetRawInputDevices(
+    EventBitMask event,
+    DWORD flags) {
+  DCHECK(ui_task_runner_->BelongsToCurrentThread());
+
+  scoped_ptr<RAWINPUTDEVICE> device(new RAWINPUTDEVICE());
+  if (event == MOUSE_EVENT_MASK) {
+    device->dwFlags = flags;
+    device->usUsagePage = kGenericDesktopPage;
+    device->usUsage = kMouseUsage;
+    device->hwndTarget = window_->hwnd();
+  } else {
+    DCHECK_EQ(KEYBOARD_EVENT_MASK, event);
+    device->dwFlags = flags;
+    device->usUsagePage = kGenericDesktopPage;
+    device->usUsage = kKeyboardUsage;
+    device->hwndTarget = window_->hwnd();
+  }
+  return device.release();
+}
+
+//
+// Implementation of UserInputMonitorWin.
+//
+
+UserInputMonitorWin::UserInputMonitorWin(
+    const scoped_refptr<base::SingleThreadTaskRunner>& ui_task_runner)
+    : core_(new Core(ui_task_runner)) {}
+UserInputMonitorWin::~UserInputMonitorWin() {

[Sergey Ulanov, 2013/09/10 18:28:39]

nit: empty lines between methods please.

[jiayl, 2013/09/10 18:34:15]

Done.

+  if (!core_->ui_task_runner()->DeleteSoon(FROM_HERE, core_))
+    delete core_;
+}
+void UserInputMonitorWin::AddMouseListener(MouseEventListener* listener) {
+  core_->AddMouseListener(listener);
+}
+void UserInputMonitorWin::RemoveMouseListener(MouseEventListener* listener) {
+  core_->RemoveMouseListener(listener);
+}
+size_t UserInputMonitorWin::GetKeyPressCount() const {
+  return core_->GetKeyPressCount();
+}
+void UserInputMonitorWin::StartKeyboardMonitoring() {
+  core_->StartKeyboardMonitoring();
+}
+void UserInputMonitorWin::StopKeyboardMonitoring() {
+  core_->StopKeyboardMonitoring();
+}
+
+}  // namespace
+
 scoped_ptr<UserInputMonitor> UserInputMonitor::Create(
-    const scoped_refptr<base::SingleThreadTaskRunner>& input_task_runner,
+    const scoped_refptr<base::SingleThreadTaskRunner>& io_task_runner,
     const scoped_refptr<base::SingleThreadTaskRunner>& ui_task_runner) {
-  return scoped_ptr<UserInputMonitor>();
+  return scoped_ptr<UserInputMonitor>(new UserInputMonitorWin(ui_task_runner));
 }
 
 }  // namespace media