Add support for device removal/arrival detection with device type. For now this allows us to detect…

content/browser/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 "content/browser/system_message_window_win.h"
 
-#include <windows.h>
 #include <dbt.h>
+#include <ks.h>
+#include <ksmedia.h>
 
 #include "base/logging.h"
 #include "base/system_monitor/system_monitor.h"
 #include "base/win/wrapped_window_proc.h"
 
-static const wchar_t* const WindowClassName = L"Chrome_SystemMessageWindow";
+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 },
+};
+}
+
+// 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;
+    for (int i = 0; i < arraysize(kDeviceCategoryMap); ++i) {
+      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 (int 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(
-      WindowClassName,
+      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(WindowClassName,
+  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(WindowClassName, instance_);
+    UnregisterClass(kWindowClassName, instance_);
   }
 }
 
-LRESULT SystemMessageWindowWin::OnDeviceChange(UINT event_type, DWORD data) {
+LRESULT SystemMessageWindowWin::OnDeviceChange(UINT event_type,
+                                               DWORD_PTR data) {
   base::SystemMonitor* monitor = base::SystemMonitor::Get();
+  base::SystemMonitor::DeviceType device_type =
+      base::SystemMonitor::DEVTYPE_UNKNOWN;
   switch (event_type) {
     case DBT_DEVNODES_CHANGED:
-      monitor->ProcessDevicesChanged(base::SystemMonitor::DEVTYPE_UNKNOWN);
+      // 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);
+      DCHECK_EQ(device_interface->dbcc_devicetype,
+                static_cast<DWORD>(DBT_DEVTYP_DEVICEINTERFACE));
+      for (int i = 0; i < arraysize(kDeviceCategoryMap); ++i) {
+        if (kDeviceCategoryMap[i].device_category ==
+            device_interface->dbcc_classguid) {
+          device_type = kDeviceCategoryMap[i].device_type;
+          break;
+        }
+      }
+
+      if (device_type == base::SystemMonitor::DEVTYPE_UNKNOWN) {
+        DVLOG(1) << "Ignoring device of unknown type arrival/removal.";

[Lei Zhang, 2012/07/31 05:15:54]

The Windows gamepad code needs this as well. You need to put gamepad devices in
kDeviceCategoryMap.

[tommi (sloooow) - chröme, 2012/07/31 09:56:15]

We also get the DBT_DEVNODES_CHANGED notification above so the functionality for
gamepad is unchanged.  I removed this DVLOG and added comments to explain why we
return here.

Here's the background:
The DBT_DEVICEREMOVECOMPLETE/DBT_DEVICEARRIVAL notifications are new and come in
addition of the DBT_DEVNODES_CHANGED notification.  When a gamepad device is
plugged in/unplugged, we have the same functionality as today, but for an audio
or video capture device, we'll get two or more notifications (>2 for composite
devices).  One of those notifications will have device_type set to
AUDIO_CAPTURE/VIDEO_CAPTURE, but the others (received via DBT_DEVNODE_CHANGED)
will have device_type==DEVTYPE_UNKNOWN.

The MediaStreamManager will ignore notifications for DEVTYPE_UNKNOWN and handle
only the audio/video ones.

The gamepad code could do something similar as well, but when we add that
functionality we have to update the devtype enum, add gamepad devices to the
kDeviceCategoryMap, and then updated the linux and mac device detection code as
well.

+        return TRUE;
+      }
+      break;
+    }
+
+    default:
+      DVLOG(1) << "Ignoring device notification " << event_type;
+      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),
-                            static_cast<DWORD>(lparam));
+                            static_cast<DWORD_PTR>(lparam));
     default:
       break;
   }
 
   return ::DefWindowProc(hwnd, message, wparam, lparam);
 }