Web MIDI: make MidiManagerMac notify device connection status

To handle device connection status, MidiManager and MidiMessageFilter
hold all devices as a list. These lists are modified by event
notifications that are delivered asynchronously.

They do not remove disconnected devices, but just mark as disconnected.
This is useful when JavaScript has a reference to a device
that got disconnected. The reference can be availalbe if the device
gets connected again.

BUG=422333
TEST=media_unittests

Review URL: https://codereview.chromium.org/662233002

Cr-Commit-Position: refs/heads/master@{#317000}

16 files changed, 192 insertions, 23 deletions

diff --git a/content/browser/media/midi_host.cc b/content/browser/media/midi_host.cc
index 37e5411..b8fcdd0 100644
--- a/content/browser/media/midi_host.cc
+++ b/content/browser/media/midi_host.cc
@@ -145,6 +145,14 @@ void MidiHost::AddOutputPort(const media::MidiPortInfo& info) {
   Send(new MidiMsg_AddOutputPort(info));
 }
 
+void MidiHost::SetInputPortState(uint32 port, media::MidiPortState state) {
+  Send(new MidiMsg_SetInputPortState(port, state));
+}
+
+void MidiHost::SetOutputPortState(uint32 port, media::MidiPortState state) {
+  Send(new MidiMsg_SetOutputPortState(port, state));
+}
+
 void MidiHost::ReceiveMidiData(
     uint32 port,
     const uint8* data,
diff --git a/content/browser/media/midi_host.h b/content/browser/media/midi_host.h
index 3a469bf..9d9c01f 100644
--- a/content/browser/media/midi_host.h
+++ b/content/browser/media/midi_host.h
@@ -16,6 +16,7 @@
 #include "content/public/browser/browser_message_filter.h"
 #include "content/public/browser/browser_thread.h"
 #include "media/midi/midi_manager.h"
+#include "media/midi/midi_port_info.h"
 
 namespace media {
 class MidiManager;
@@ -39,6 +40,8 @@ class CONTENT_EXPORT MidiHost
   void CompleteStartSession(media::MidiResult result) override;
   void AddInputPort(const media::MidiPortInfo& info) override;
   void AddOutputPort(const media::MidiPortInfo& info) override;
+  void SetInputPortState(uint32 port, media::MidiPortState state) override;
+  void SetOutputPortState(uint32 port, media::MidiPortState state) override;
   void ReceiveMidiData(uint32 port,
                        const uint8* data,
                        size_t length,
diff --git a/content/common/media/midi_messages.h b/content/common/media/midi_messages.h
index 6f314b6..6147c8a 100644
--- a/content/common/media/midi_messages.h
+++ b/content/common/media/midi_messages.h
@@ -17,11 +17,15 @@
 #define IPC_MESSAGE_EXPORT CONTENT_EXPORT
 #define IPC_MESSAGE_START MidiMsgStart
 
+IPC_ENUM_TRAITS_MAX_VALUE(media::MidiPortState,
+                          media::MIDI_PORT_STATE_LAST)
+
 IPC_STRUCT_TRAITS_BEGIN(media::MidiPortInfo)
   IPC_STRUCT_TRAITS_MEMBER(id)
   IPC_STRUCT_TRAITS_MEMBER(manufacturer)
   IPC_STRUCT_TRAITS_MEMBER(name)
   IPC_STRUCT_TRAITS_MEMBER(version)
+  IPC_STRUCT_TRAITS_MEMBER(state)
 IPC_STRUCT_TRAITS_END()
 
 IPC_ENUM_TRAITS_MAX_VALUE(media::MidiResult, media::MIDI_RESULT_LAST)
@@ -46,6 +50,14 @@ IPC_MESSAGE_CONTROL1(MidiMsg_AddInputPort,
 IPC_MESSAGE_CONTROL1(MidiMsg_AddOutputPort,
                      media::MidiPortInfo /* output port */)
 
+IPC_MESSAGE_CONTROL2(MidiMsg_SetInputPortState,
+                     uint32 /* port */,
+                     media::MidiPortState /* state */)
+
+IPC_MESSAGE_CONTROL2(MidiMsg_SetOutputPortState,
+                     uint32 /* port */,
+                     media::MidiPortState /* state */)
+
 IPC_MESSAGE_CONTROL1(MidiMsg_SessionStarted,
                      media::MidiResult /* result */)
 
diff --git a/content/renderer/media/midi_message_filter.cc b/content/renderer/media/midi_message_filter.cc
index 03a9d00..258d04d 100644
--- a/content/renderer/media/midi_message_filter.cc
+++ b/content/renderer/media/midi_message_filter.cc
@@ -116,6 +116,8 @@ bool MidiMessageFilter::OnMessageReceived(const IPC::Message& message) {
     IPC_MESSAGE_HANDLER(MidiMsg_SessionStarted, OnSessionStarted)
     IPC_MESSAGE_HANDLER(MidiMsg_AddInputPort, OnAddInputPort)
     IPC_MESSAGE_HANDLER(MidiMsg_AddOutputPort, OnAddOutputPort)
+    IPC_MESSAGE_HANDLER(MidiMsg_SetInputPortState, OnSetInputPortState)
+    IPC_MESSAGE_HANDLER(MidiMsg_SetOutputPortState, OnSetOutputPortState)
     IPC_MESSAGE_HANDLER(MidiMsg_DataReceived, OnDataReceived)
     IPC_MESSAGE_HANDLER(MidiMsg_AcknowledgeSentData, OnAcknowledgeSentData)
     IPC_MESSAGE_UNHANDLED(handled = false)
@@ -163,6 +165,24 @@ void MidiMessageFilter::OnAddOutputPort(media::MidiPortInfo info) {
       base::Bind(&MidiMessageFilter::HandleAddOutputPort, this, info));
 }
 
+void MidiMessageFilter::OnSetInputPortState(uint32 port,
+                                            media::MidiPortState state) {
+  DCHECK(io_message_loop_->BelongsToCurrentThread());
+  main_message_loop_->PostTask(
+      FROM_HERE,
+      base::Bind(&MidiMessageFilter::HandleSetInputPortState,
+                 this, port, state));
+}
+
+void MidiMessageFilter::OnSetOutputPortState(uint32 port,
+                                             media::MidiPortState state) {
+  DCHECK(io_message_loop_->BelongsToCurrentThread());
+  main_message_loop_->PostTask(
+      FROM_HERE,
+      base::Bind(&MidiMessageFilter::HandleSetOutputPortState,
+                 this, port, state));
+}
+
 void MidiMessageFilter::OnDataReceived(uint32 port,
                                        const std::vector<uint8>& data,
                                        double timestamp) {
@@ -265,4 +285,18 @@ void MidiMessageFilter::HandleAckknowledgeSentData(size_t bytes_sent) {
     unacknowledged_bytes_sent_ -= bytes_sent;
 }
 
+void MidiMessageFilter::HandleSetInputPortState(uint32 port,
+                                                media::MidiPortState state) {
+  DCHECK(main_message_loop_->BelongsToCurrentThread());
+  inputs_[port].state = state;
+  // TODO(toyoshim): Notify to all clients.
+}
+
+void MidiMessageFilter::HandleSetOutputPortState(uint32 port,
+                                                 media::MidiPortState state) {
+  DCHECK(main_message_loop_->BelongsToCurrentThread());
+  outputs_[port].state = state;
+  // TODO(toyoshim): Notify to all clients.
+}
+
 }  // namespace content
diff --git a/content/renderer/media/midi_message_filter.h b/content/renderer/media/midi_message_filter.h
index f7e1a84..83e760a 100644
--- a/content/renderer/media/midi_message_filter.h
+++ b/content/renderer/media/midi_message_filter.h
@@ -77,6 +77,12 @@ class CONTENT_EXPORT MidiMessageFilter : public IPC::MessageFilter {
   void OnAddInputPort(media::MidiPortInfo info);
   void OnAddOutputPort(media::MidiPortInfo info);
 
+  // These functions are called to notify the recipient that a device that is
+  // notified via OnAddInputPort() or OnAddOutputPort() gets disconnected, or
+  // connected again.
+  void OnSetInputPortState(uint32 port, media::MidiPortState state);
+  void OnSetOutputPortState(uint32 port, media::MidiPortState state);
+
   // Called when the browser process has sent MIDI data containing one or
   // more messages.
   void OnDataReceived(uint32 port,
@@ -93,6 +99,8 @@ class CONTENT_EXPORT MidiMessageFilter : public IPC::MessageFilter {
 
   void HandleAddInputPort(media::MidiPortInfo info);
   void HandleAddOutputPort(media::MidiPortInfo info);
+  void HandleSetInputPortState(uint32 port, media::MidiPortState state);
+  void HandleSetOutputPortState(uint32 port, media::MidiPortState state);
 
   void HandleDataReceived(uint32 port,
                           const std::vector<uint8>& data,
diff --git a/media/midi/midi_manager.cc b/media/midi/midi_manager.cc
index 9e1f1e2..f7de36f 100644
--- a/media/midi/midi_manager.cc
+++ b/media/midi/midi_manager.cc
@@ -130,6 +130,22 @@ void MidiManager::AddOutputPort(const MidiPortInfo& info) {
     client->AddOutputPort(info);
 }
 
+void MidiManager::SetInputPortState(uint32 port_index, MidiPortState state) {
+  base::AutoLock auto_lock(lock_);
+  DCHECK_LT(port_index, input_ports_.size());
+  input_ports_[port_index].state = state;
+  for (auto client : clients_)
+    client->SetInputPortState(port_index, state);
+}
+
+void MidiManager::SetOutputPortState(uint32 port_index, MidiPortState state) {
+  base::AutoLock auto_lock(lock_);
+  DCHECK_LT(port_index, output_ports_.size());
+  output_ports_[port_index].state = state;
+  for (auto client : clients_)
+    client->SetOutputPortState(port_index, state);
+}
+
 void MidiManager::ReceiveMidiData(
     uint32 port_index,
     const uint8* data,
diff --git a/media/midi/midi_manager.h b/media/midi/midi_manager.h
index d7e7e47..a7c5262 100644
--- a/media/midi/midi_manager.h
+++ b/media/midi/midi_manager.h
@@ -35,10 +35,10 @@ class MEDIA_EXPORT MidiManagerClient {
   virtual void AddInputPort(const MidiPortInfo& info) = 0;
   virtual void AddOutputPort(const MidiPortInfo& info) = 0;
 
-  // TODO(toyoshim): DisableInputPort(const MidiPortInfo& info) and
-  // DisableOutputPort(const MidiPortInfo& info) should be added.
-  // On DisableInputPort(), internal states, e.g. received_messages_queues in
-  // MidiHost, should be reset.
+  // SetInputPortState() and SetOutputPortState() are called to notify a known
+  // device gets disconnected, or connected again.
+  virtual void SetInputPortState(uint32 port_index, MidiPortState state) = 0;
+  virtual void SetOutputPortState(uint32 port_index, MidiPortState state) = 0;
 
   // CompleteStartSession() is called when platform dependent preparation is
   // finished.
@@ -122,6 +122,8 @@ class MEDIA_EXPORT MidiManager {
 
   void AddInputPort(const MidiPortInfo& info);
   void AddOutputPort(const MidiPortInfo& info);
+  void SetInputPortState(uint32 port_index, MidiPortState state);
+  void SetOutputPortState(uint32 port_index, MidiPortState state);
 
   // Dispatches to all clients.
   // TODO(toyoshim): Fix the mac implementation to use
diff --git a/media/midi/midi_manager_alsa.cc b/media/midi/midi_manager_alsa.cc
index e4cadfb..9043f1f 100644
--- a/media/midi/midi_manager_alsa.cc
+++ b/media/midi/midi_manager_alsa.cc
@@ -252,7 +252,8 @@ void MidiManagerAlsa::StartInitialization() {
             VLOG(1) << "snd_seq_subscribe_port fails: " << snd_strerror(err);
           } else {
             source_map_[AddrToInt(sender)] = current_input++;
-            AddInputPort(MidiPortInfo(id, manufacturer, name, version));
+            AddInputPort(MidiPortInfo(
+                id, manufacturer, name, version, MIDI_PORT_OPENED));
           }
         }
         if ((caps & kRequiredOutputPortCaps) == kRequiredOutputPortCaps) {
@@ -286,7 +287,8 @@ void MidiManagerAlsa::StartInitialization() {
             snd_midi_event_new(kSendBufferSize, &encoder);
             encoders_.push_back(encoder);
             out_ports_.push_back(out_port);
-            AddOutputPort(MidiPortInfo(id, manufacturer, name, version));
+            AddOutputPort(MidiPortInfo(
+                id, manufacturer, name, version, MIDI_PORT_OPENED));
           }
         }
       }
diff --git a/media/midi/midi_manager_mac.cc b/media/midi/midi_manager_mac.cc
index e9d56fb..8a9e0607 100644
--- a/media/midi/midi_manager_mac.cc
+++ b/media/midi/midi_manager_mac.cc
@@ -4,6 +4,7 @@
 
 #include "media/midi/midi_manager_mac.h"
 
+#include <algorithm>
 #include <string>
 
 #include "base/bind.h"
@@ -25,8 +26,7 @@ namespace media {
 
 namespace {
 
-MidiPortInfo GetPortInfoFromEndpoint(
-    MIDIEndpointRef endpoint) {
+MidiPortInfo GetPortInfoFromEndpoint(MIDIEndpointRef endpoint) {
   SInt32 id_number = 0;
   MIDIObjectGetIntegerProperty(endpoint, kMIDIPropertyUniqueID, &id_number);
   string id = IntToString(id_number);
@@ -65,7 +65,8 @@ MidiPortInfo GetPortInfoFromEndpoint(
                   << result;
   }
 
-  return MidiPortInfo(id, manufacturer, name, version);
+  const MidiPortState state = MIDI_PORT_OPENED;
+  return MidiPortInfo(id, manufacturer, name, version, state);
 }
 
 double MIDITimeStampToSeconds(MIDITimeStamp timestamp) {
@@ -140,7 +141,8 @@ void MidiManagerMac::InitializeCoreMIDI() {
   // TODO(toyoshim): Set MIDINotifyProc to receive CoreMIDI event notifications.
   midi_client_ = 0;
   OSStatus result =
-      MIDIClientCreate(CFSTR("Chrome"), NULL, NULL, &midi_client_);
+      MIDIClientCreate(CFSTR("Chrome"), ReceiveMidiNotifyDispatch, this,
+                       &midi_client_);
 
   if (result != noErr)
     return CompleteInitialization(MIDI_INITIALIZATION_ERROR);
@@ -200,6 +202,61 @@ void MidiManagerMac::InitializeCoreMIDI() {
 }
 
 // static
+void MidiManagerMac::ReceiveMidiNotifyDispatch(const MIDINotification* message,
+                                               void* refcon) {
+  MidiManagerMac* manager = static_cast<MidiManagerMac*>(refcon);
+  manager->ReceiveMidiNotify(message);
+}
+
+void MidiManagerMac::ReceiveMidiNotify(const MIDINotification* message) {
+  DCHECK(client_thread_.message_loop_proxy()->BelongsToCurrentThread());
+
+  if (kMIDIMsgObjectAdded == message->messageID) {
+    const MIDIObjectAddRemoveNotification* notification =
+        reinterpret_cast<const MIDIObjectAddRemoveNotification*>(message);
+    MIDIEndpointRef endpoint =
+        static_cast<MIDIEndpointRef>(notification->child);
+    if (notification->childType == kMIDIObjectType_Source) {
+      SourceMap::iterator it = source_map_.find(endpoint);
+      if (it == source_map_.end()) {
+        uint32 index = source_map_.size();
+        source_map_[endpoint] = index;
+        MidiPortInfo info = GetPortInfoFromEndpoint(endpoint);
+        AddInputPort(info);
+      } else {
+        uint32 index = it->second;
+        SetInputPortState(index, MIDI_PORT_OPENED);
+      }
+    } else if (notification->childType == kMIDIObjectType_Destination) {
+      auto i = std::find(destinations_.begin(), destinations_.end(), endpoint);
+      if (i != destinations_.end()) {
+        SetOutputPortState(i - destinations_.begin(), MIDI_PORT_OPENED);
+      } else {
+        destinations_.push_back(endpoint);
+        MidiPortInfo info = GetPortInfoFromEndpoint(endpoint);
+        AddOutputPort(info);
+      }
+    }
+  } else if (kMIDIMsgObjectRemoved == message->messageID) {
+    const MIDIObjectAddRemoveNotification* notification =
+        reinterpret_cast<const MIDIObjectAddRemoveNotification*>(message);
+    MIDIEndpointRef endpoint =
+        static_cast<MIDIEndpointRef>(notification->child);
+    if (notification->childType == kMIDIObjectType_Source) {
+      SourceMap::iterator it = source_map_.find(endpoint);
+      if (it != source_map_.end()) {
+        uint32 index = it->second;
+        SetInputPortState(index, MIDI_PORT_DISCONNECTED);
+      }
+    } else if (notification->childType == kMIDIObjectType_Destination) {
+      auto i = std::find(destinations_.begin(), destinations_.end(), endpoint);
+      if (i != destinations_.end())
+        SetOutputPortState(i - destinations_.begin(), MIDI_PORT_DISCONNECTED);
+    }
+  }
+}
+
+// static
 void MidiManagerMac::ReadMidiDispatch(const MIDIPacketList* packet_list,
                                       void* read_proc_refcon,
                                       void* src_conn_refcon) {
diff --git a/media/midi/midi_manager_mac.h b/media/midi/midi_manager_mac.h
index f7179ec..e8e4474 100644
--- a/media/midi/midi_manager_mac.h
+++ b/media/midi/midi_manager_mac.h
@@ -42,13 +42,18 @@ class MEDIA_EXPORT MidiManagerMac : public MidiManager {
   // StartInitialization().
   void InitializeCoreMIDI();
 
+  // CoreMIDI callback for MIDI notification.
+  // Receives MIDI related event notifications from CoreMIDI.
+  static void ReceiveMidiNotifyDispatch(const MIDINotification* message,
+                                        void* refcon);
+  void ReceiveMidiNotify(const MIDINotification* message);
+
   // CoreMIDI callback for MIDI data.
   // Each callback can contain multiple packets, each of which can contain
   // multiple MIDI messages.
-  static void ReadMidiDispatch(
-      const MIDIPacketList *pktlist,
-      void *read_proc_refcon,
-      void *src_conn_refcon);
+  static void ReadMidiDispatch(const MIDIPacketList* packet_list,
+                               void* read_proc_refcon,
+                               void* src_conn_refcon);
   virtual void ReadMidi(MIDIEndpointRef source, const MIDIPacketList *pktlist);
 
   // An internal callback that runs on MidiSendThread.
@@ -67,13 +72,13 @@ class MEDIA_EXPORT MidiManagerMac : public MidiManager {
   MIDIPacketList* packet_list_;
   MIDIPacket* midi_packet_;
 
-  typedef std::map<MIDIEndpointRef, uint32> SourceMap;
-
   // Keeps track of the index (0-based) for each of our sources.
+  typedef std::map<MIDIEndpointRef, uint32> SourceMap;
   SourceMap source_map_;
 
   // Keeps track of all destinations.
-  std::vector<MIDIEndpointRef> destinations_;
+  typedef std::vector<MIDIEndpointRef> DestinationVector;
+  DestinationVector destinations_;
 
   // |client_thread_| is used to handle platform dependent operations.
   base::Thread client_thread_;
diff --git a/media/midi/midi_manager_unittest.cc b/media/midi/midi_manager_unittest.cc
index 40d9152..680f9db 100644
--- a/media/midi/midi_manager_unittest.cc
+++ b/media/midi/midi_manager_unittest.cc
@@ -62,6 +62,8 @@ class FakeMidiManagerClient : public MidiManagerClient {
   // MidiManagerClient implementation.
   void AddInputPort(const MidiPortInfo& info) override {}
   void AddOutputPort(const MidiPortInfo& info) override {}
+  void SetInputPortState(uint32 port_index, MidiPortState state) override {}
+  void SetOutputPortState(uint32 port_index, MidiPortState state) override {}
 
   void CompleteStartSession(MidiResult result) override {
     EXPECT_TRUE(wait_for_result_);
diff --git a/media/midi/midi_manager_usb.cc b/media/midi/midi_manager_usb.cc
index 63c241b..67953e4 100644
--- a/media/midi/midi_manager_usb.cc
+++ b/media/midi/midi_manager_usb.cc
@@ -106,6 +106,7 @@ void MidiManagerUsb::OnEnumerateDevicesDone(bool result,
         // setting is sufficiently unique although there is no user-friendly
         // meaning.
         MidiPortInfo port;
+        port.state = MIDI_PORT_OPENED;
         port.id = base::StringPrintf("port-%ld-%ld",
                                      static_cast<long>(i),
                                      static_cast<long>(j));
@@ -115,6 +116,7 @@ void MidiManagerUsb::OnEnumerateDevicesDone(bool result,
         input_jacks.push_back(jacks[j]);
         // TODO(yhirano): Set appropriate properties.
         MidiPortInfo port;
+        port.state = MIDI_PORT_OPENED;
         port.id = base::StringPrintf("port-%ld-%ld",
                                      static_cast<long>(i),
                                      static_cast<long>(j));
diff --git a/media/midi/midi_manager_usb_unittest.cc b/media/midi/midi_manager_usb_unittest.cc
index 8552403..d59f857 100644
--- a/media/midi/midi_manager_usb_unittest.cc
+++ b/media/midi/midi_manager_usb_unittest.cc
@@ -86,6 +86,10 @@ class FakeMidiManagerClient : public MidiManagerClient {
     output_ports_.push_back(info);
   }
 
+  void SetInputPortState(uint32 port_index, MidiPortState state) override {}
+
+  void SetOutputPortState(uint32 port_index, MidiPortState state) override {}
+
   void CompleteStartSession(MidiResult result) override {
     complete_start_session_ = true;
     result_ = result;
diff --git a/media/midi/midi_manager_win.cc b/media/midi/midi_manager_win.cc
index bc4b15d..26657d6 100644
--- a/media/midi/midi_manager_win.cc
+++ b/media/midi/midi_manager_win.cc
@@ -515,7 +515,8 @@ void MidiManagerWin::StartInitialization() {
         base::IntToString(static_cast<int>(device_id)),
         "",
         base::WideToUTF8(caps.szPname),
-        base::IntToString(static_cast<int>(caps.vDriverVersion)));
+        base::IntToString(static_cast<int>(caps.vDriverVersion)),
+        MIDI_PORT_OPENED);
     AddInputPort(info);
     in_device->set_port_index(inport_index++);
     in_devices_.push_back(in_device.release());
@@ -538,7 +539,8 @@ void MidiManagerWin::StartInitialization() {
         base::IntToString(static_cast<int>(device_id)),
         "",
         base::WideToUTF8(caps.szPname),
-        base::IntToString(static_cast<int>(caps.vDriverVersion)));
+        base::IntToString(static_cast<int>(caps.vDriverVersion)),
+        MIDI_PORT_OPENED);
     AddOutputPort(info);
     out_devices_.push_back(out_port.release());
   }
diff --git a/media/midi/midi_port_info.cc b/media/midi/midi_port_info.cc
index 02b4aa9..020394e 100644
--- a/media/midi/midi_port_info.cc
+++ b/media/midi/midi_port_info.cc
@@ -11,11 +11,13 @@ MidiPortInfo::MidiPortInfo() {}
 MidiPortInfo::MidiPortInfo(const std::string& in_id,
                            const std::string& in_manufacturer,
                            const std::string& in_name,
-                           const std::string& in_version)
+                           const std::string& in_version,
+                           MidiPortState in_state)
     : id(in_id),
       manufacturer(in_manufacturer),
       name(in_name),
-      version(in_version) {}
+      version(in_version),
+      state(in_state) {}
 
 MidiPortInfo::~MidiPortInfo() {}
 
@@ -23,6 +25,7 @@ MidiPortInfo::MidiPortInfo(const MidiPortInfo& info)
     : id(info.id),
       manufacturer(info.manufacturer),
       name(info.name),
-      version(info.version) {}
+      version(info.version),
+      state(info.state) {}
 
 }  // namespace media
diff --git a/media/midi/midi_port_info.h b/media/midi/midi_port_info.h
index 1fe3bca..32b94b4 100644
--- a/media/midi/midi_port_info.h
+++ b/media/midi/midi_port_info.h
@@ -13,12 +13,20 @@
 
 namespace media {
 
+enum MidiPortState {
+  MIDI_PORT_DISCONNECTED,
+  MIDI_PORT_CONNECTED,
+  MIDI_PORT_OPENED,
+  MIDI_PORT_STATE_LAST = MIDI_PORT_OPENED,
+};
+
 struct MEDIA_EXPORT MidiPortInfo {
   MidiPortInfo();
   MidiPortInfo(const std::string& in_id,
                const std::string& in_manufacturer,
                const std::string& in_name,
-               const std::string& in_version);
+               const std::string& in_version,
+               MidiPortState in_state);
 
   MidiPortInfo(const MidiPortInfo& info);
   ~MidiPortInfo();
@@ -27,6 +35,7 @@ struct MEDIA_EXPORT MidiPortInfo {
   std::string manufacturer;
   std::string name;
   std::string version;
+  MidiPortState state;
 };
 
 typedef std::vector<MidiPortInfo> MidiPortInfoList;