Move device monitors out of //media/capture into //media/device_monitors

media/capture/system_message_window_win.cc

-// Copyright (c) 2012 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/capture/system_message_window_win.h"
-
-#include <dbt.h>
-#include <stddef.h>
-
-#include "base/logging.h"
-#include "base/macros.h"
-#include "base/system_monitor/system_monitor.h"
-#include "base/win/wrapped_window_proc.h"
-#include "media/audio/win/core_audio_util_win.h"
-
-namespace media {
-
-namespace {
-const wchar_t kWindowClassName[] = L"Chrome_SystemMessageWindow";
-
-// A static map from a device category guid to base::SystemMonitor::DeviceType.
-struct {
-  const GUID device_category;
-  const base::SystemMonitor::DeviceType device_type;
-} const kDeviceCategoryMap[] = {
-    {KSCATEGORY_AUDIO, base::SystemMonitor::DEVTYPE_AUDIO_CAPTURE},
-    {KSCATEGORY_VIDEO, base::SystemMonitor::DEVTYPE_VIDEO_CAPTURE},
-};
-}  // namespace
-
-// Manages the device notification handles for SystemMessageWindowWin.
-class SystemMessageWindowWin::DeviceNotifications {
- public:
-  explicit DeviceNotifications(HWND hwnd) : notifications_() { Register(hwnd); }
-
-  ~DeviceNotifications() { Unregister(); }
-
-  void Register(HWND hwnd) {
-    // Request to receive device notifications.  All applications receive basic
-    // notifications via WM_DEVICECHANGE but in order to receive detailed device
-    // arrival and removal messages, we need to register.
-    DEV_BROADCAST_DEVICEINTERFACE filter = {0};
-    filter.dbcc_size = sizeof(filter);
-    filter.dbcc_devicetype = DBT_DEVTYP_DEVICEINTERFACE;
-    bool core_audio_support = media::CoreAudioUtil::IsSupported();
-    for (size_t i = 0; i < arraysize(kDeviceCategoryMap); ++i) {
-      // If CoreAudio is supported, AudioDeviceListenerWin will
-      // take care of monitoring audio devices.
-      if (core_audio_support &&
-          KSCATEGORY_AUDIO == kDeviceCategoryMap[i].device_category) {
-        continue;
-      }
-
-      filter.dbcc_classguid = kDeviceCategoryMap[i].device_category;
-      DCHECK_EQ(notifications_[i], static_cast<HDEVNOTIFY>(NULL));
-      notifications_[i] = RegisterDeviceNotification(
-          hwnd, &filter, DEVICE_NOTIFY_WINDOW_HANDLE);
-      DPLOG_IF(ERROR, !notifications_[i])
-          << "RegisterDeviceNotification failed";
-    }
-  }
-
-  void Unregister() {
-    for (size_t i = 0; i < arraysize(notifications_); ++i) {
-      if (notifications_[i]) {
-        UnregisterDeviceNotification(notifications_[i]);
-        notifications_[i] = NULL;
-      }
-    }
-  }
-
- private:
-  HDEVNOTIFY notifications_[arraysize(kDeviceCategoryMap)];
-
-  DISALLOW_IMPLICIT_CONSTRUCTORS(DeviceNotifications);
-};
-
-SystemMessageWindowWin::SystemMessageWindowWin() {
-  WNDCLASSEX window_class;
-  base::win::InitializeWindowClass(
-      kWindowClassName,
-      &base::win::WrappedWindowProc<SystemMessageWindowWin::WndProcThunk>, 0, 0,
-      0, NULL, NULL, NULL, NULL, NULL, &window_class);
-  instance_ = window_class.hInstance;
-  ATOM clazz = RegisterClassEx(&window_class);
-  DCHECK(clazz);
-
-  window_ =
-      CreateWindow(kWindowClassName, 0, 0, 0, 0, 0, 0, 0, 0, instance_, 0);
-  SetWindowLongPtr(window_, GWLP_USERDATA, reinterpret_cast<LONG_PTR>(this));
-  device_notifications_.reset(new DeviceNotifications(window_));
-}
-
-SystemMessageWindowWin::~SystemMessageWindowWin() {
-  if (window_) {
-    DestroyWindow(window_);
-    UnregisterClass(kWindowClassName, instance_);
-  }
-}
-
-LRESULT SystemMessageWindowWin::OnDeviceChange(UINT event_type, LPARAM data) {
-  base::SystemMonitor* monitor = base::SystemMonitor::Get();
-  base::SystemMonitor::DeviceType device_type =
-      base::SystemMonitor::DEVTYPE_UNKNOWN;
-  switch (event_type) {
-    case DBT_DEVNODES_CHANGED:
-      // For this notification, we're happy with the default DEVTYPE_UNKNOWN.
-      break;
-
-    case DBT_DEVICEREMOVECOMPLETE:
-    case DBT_DEVICEARRIVAL: {
-      // This notification has more details about the specific device that
-      // was added or removed.  See if this is a category we're interested
-      // in monitoring and if so report the specific device type.  If we don't
-      // find the category in our map, ignore the notification and do not
-      // notify the system monitor.
-      DEV_BROADCAST_DEVICEINTERFACE* device_interface =
-          reinterpret_cast<DEV_BROADCAST_DEVICEINTERFACE*>(data);
-      if (device_interface->dbcc_devicetype != DBT_DEVTYP_DEVICEINTERFACE)
-        return TRUE;
-      for (const auto& map_entry : kDeviceCategoryMap) {
-        if (map_entry.device_category == device_interface->dbcc_classguid) {
-          device_type = map_entry.device_type;
-          break;
-        }
-      }
-
-      // Devices that we do not have a DEVTYPE_ for, get detected via
-      // DBT_DEVNODES_CHANGED, so we avoid sending additional notifications
-      // for those here.
-      if (device_type == base::SystemMonitor::DEVTYPE_UNKNOWN)
-        return TRUE;
-      break;
-    }
-
-    default:
-      return TRUE;
-  }
-
-  monitor->ProcessDevicesChanged(device_type);
-
-  return TRUE;
-}
-
-LRESULT CALLBACK SystemMessageWindowWin::WndProc(HWND hwnd,
-                                                 UINT message,
-                                                 WPARAM wparam,
-                                                 LPARAM lparam) {
-  switch (message) {
-    case WM_DEVICECHANGE:
-      return OnDeviceChange(static_cast<UINT>(wparam), lparam);
-    default:
-      break;
-  }
-
-  return ::DefWindowProc(hwnd, message, wparam, lparam);
-}
-
-}  // namespace media