1// Copyright (c) 2012 The Chromium Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5#include "content/browser/system_message_window_win.h"
6
7#include <dbt.h>
8
9#include "base/logging.h"
10#include "base/system_monitor/system_monitor.h"
11#include "base/win/wrapped_window_proc.h"
12#include "media/audio/win/core_audio_util_win.h"
13
14namespace content {
15
16namespace {
17const wchar_t kWindowClassName[] = L"Chrome_SystemMessageWindow";
18
19// A static map from a device category guid to base::SystemMonitor::DeviceType.
20struct {
21  const GUID device_category;
22  const base::SystemMonitor::DeviceType device_type;
23} const kDeviceCategoryMap[] = {
24  { KSCATEGORY_AUDIO, base::SystemMonitor::DEVTYPE_AUDIO_CAPTURE },
25  { KSCATEGORY_VIDEO, base::SystemMonitor::DEVTYPE_VIDEO_CAPTURE },
26};
27}  // namespace
28
29// Manages the device notification handles for SystemMessageWindowWin.
30class SystemMessageWindowWin::DeviceNotifications {
31 public:
32  explicit DeviceNotifications(HWND hwnd) : notifications_() {
33    Register(hwnd);
34  }
35
36  ~DeviceNotifications() {
37    Unregister();
38  }
39
40  void Register(HWND hwnd) {
41    // Request to receive device notifications.  All applications receive basic
42    // notifications via WM_DEVICECHANGE but in order to receive detailed device
43    // arrival and removal messages, we need to register.
44    DEV_BROADCAST_DEVICEINTERFACE filter = {0};
45    filter.dbcc_size = sizeof(filter);
46    filter.dbcc_devicetype = DBT_DEVTYP_DEVICEINTERFACE;
47    bool core_audio_support = media::CoreAudioUtil::IsSupported();
48    for (int i = 0; i < arraysize(kDeviceCategoryMap); ++i) {
49      // If CoreAudio is supported, AudioDeviceListenerWin will
50      // take care of monitoring audio devices.
51      if (core_audio_support &&
52          KSCATEGORY_AUDIO == kDeviceCategoryMap[i].device_category) {
53        continue;
54      }
55
56      filter.dbcc_classguid = kDeviceCategoryMap[i].device_category;
57      DCHECK_EQ(notifications_[i], static_cast<HDEVNOTIFY>(NULL));
58      notifications_[i] = RegisterDeviceNotification(
59          hwnd, &filter, DEVICE_NOTIFY_WINDOW_HANDLE);
60      DPLOG_IF(ERROR, !notifications_[i])
61          << "RegisterDeviceNotification failed";
62    }
63  }
64
65  void Unregister() {
66    for (int i = 0; i < arraysize(notifications_); ++i) {
67      if (notifications_[i]) {
68        UnregisterDeviceNotification(notifications_[i]);
69        notifications_[i] = NULL;
70      }
71    }
72  }
73
74 private:
75  HDEVNOTIFY notifications_[arraysize(kDeviceCategoryMap)];
76
77  DISALLOW_IMPLICIT_CONSTRUCTORS(DeviceNotifications);
78};
79
80
81SystemMessageWindowWin::SystemMessageWindowWin() {
82  WNDCLASSEX window_class;
83  base::win::InitializeWindowClass(
84      kWindowClassName,
85      &base::win::WrappedWindowProc<SystemMessageWindowWin::WndProcThunk>,
86      0, 0, 0, NULL, NULL, NULL, NULL, NULL,
87      &window_class);
88  instance_ = window_class.hInstance;
89  ATOM clazz = RegisterClassEx(&window_class);
90  DCHECK(clazz);
91
92  window_ = CreateWindow(kWindowClassName,
93                         0, 0, 0, 0, 0, 0, 0, 0, instance_, 0);
94  SetWindowLongPtr(window_, GWLP_USERDATA, reinterpret_cast<LONG_PTR>(this));
95  device_notifications_.reset(new DeviceNotifications(window_));
96}
97
98SystemMessageWindowWin::~SystemMessageWindowWin() {
99  if (window_) {
100    DestroyWindow(window_);
101    UnregisterClass(kWindowClassName, instance_);
102  }
103}
104
105LRESULT SystemMessageWindowWin::OnDeviceChange(UINT event_type, LPARAM data) {
106  base::SystemMonitor* monitor = base::SystemMonitor::Get();
107  base::SystemMonitor::DeviceType device_type =
108      base::SystemMonitor::DEVTYPE_UNKNOWN;
109  switch (event_type) {
110    case DBT_DEVNODES_CHANGED:
111      // For this notification, we're happy with the default DEVTYPE_UNKNOWN.
112      break;
113
114    case DBT_DEVICEREMOVECOMPLETE:
115    case DBT_DEVICEARRIVAL: {
116      // This notification has more details about the specific device that
117      // was added or removed.  See if this is a category we're interested
118      // in monitoring and if so report the specific device type.  If we don't
119      // find the category in our map, ignore the notification and do not
120      // notify the system monitor.
121      DEV_BROADCAST_DEVICEINTERFACE* device_interface =
122          reinterpret_cast<DEV_BROADCAST_DEVICEINTERFACE*>(data);
123      if (device_interface->dbcc_devicetype != DBT_DEVTYP_DEVICEINTERFACE)
124        return TRUE;
125      for (int i = 0; i < arraysize(kDeviceCategoryMap); ++i) {
126        if (kDeviceCategoryMap[i].device_category ==
127            device_interface->dbcc_classguid) {
128          device_type = kDeviceCategoryMap[i].device_type;
129          break;
130        }
131      }
132
133      // Devices that we do not have a DEVTYPE_ for, get detected via
134      // DBT_DEVNODES_CHANGED, so we avoid sending additional notifications
135      // for those here.
136      if (device_type == base::SystemMonitor::DEVTYPE_UNKNOWN)
137        return TRUE;
138      break;
139    }
140
141    default:
142      return TRUE;
143  }
144
145  monitor->ProcessDevicesChanged(device_type);
146
147  return TRUE;
148}
149
150LRESULT CALLBACK SystemMessageWindowWin::WndProc(HWND hwnd, UINT message,
151                                                 WPARAM wparam, LPARAM lparam) {
152  switch (message) {
153    case WM_DEVICECHANGE:
154      return OnDeviceChange(static_cast<UINT>(wparam), lparam);
155    default:
156      break;
157  }
158
159  return ::DefWindowProc(hwnd, message, wparam, lparam);
160}
161
162}  // namespace content
163