Web MIDI: distributes MIDIPort information asynchronously

media/midi/midi_manager.h

 // Copyright (c) 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.
 
 #ifndef MEDIA_MIDI_MIDI_MANAGER_H_
 #define MEDIA_MIDI_MIDI_MANAGER_H_
 
 #include <set>
 #include <vector>
 
@@ skipping 11 matching lines @@
 
 namespace media {
 
 // A MidiManagerClient registers with the MidiManager to receive MIDI data.
 // See MidiManager::RequestAccess() and MidiManager::ReleaseAccess()
 // for details.
 class MEDIA_EXPORT MidiManagerClient {
  public:
   virtual ~MidiManagerClient() {}
 
+  // AddInputPort() and AddOutputPort() are called before CompleteStartSession()
+  // is called to notify existing MIDI ports, and also called after that to
+  // notify new MIDI ports are added.
+  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.
+
   // CompleteStartSession() is called when platform dependent preparation is
   // finished.
   virtual void CompleteStartSession(MidiResult result) = 0;
 
   // ReceiveMidiData() is called when MIDI data has been received from the
   // MIDI system.
   // |port_index| represents the specific input port from input_ports().
   // |data| represents a series of bytes encoding one or more MIDI messages.
   // |length| is the number of bytes in |data|.
   // |timestamp| is the time the data was received, in seconds.
@@ skipping 40 matching lines @@
   // |data| represents a series of bytes encoding one or more MIDI messages.
   // |length| is the number of bytes in |data|.
   // |timestamp| is the time to send the data, in seconds. A value of 0
   // means send "now" or as soon as possible.
   // The default implementation is for unsupported platforms.
   virtual void DispatchSendMidiData(MidiManagerClient* client,
                                     uint32 port_index,
                                     const std::vector<uint8>& data,
                                     double timestamp);
 
-  // input_ports() is a list of MIDI ports for receiving MIDI data.
-  // Each individual port in this list can be identified by its
-  // integer index into this list.
-  const MidiPortInfoList& input_ports() const { return input_ports_; }
-
-  // output_ports() is a list of MIDI ports for sending MIDI data.
-  // Each individual port in this list can be identified by its
-  // integer index into this list.
-  const MidiPortInfoList& output_ports() const { return output_ports_; }
-
  protected:
   friend class MidiManagerUsb;
 
   // Initializes the platform dependent MIDI system. MidiManager class has a
   // default implementation that synchronously calls CompleteInitialization()
   // with MIDI_NOT_SUPPORTED on the caller thread. A derived class for a
   // specific platform should override this method correctly.
   // This method is called on Chrome_IOThread thread inside StartSession().
   // Platform dependent initialization can be processed synchronously or
   // asynchronously. When the initialization is completed,
@@ skipping 26 matching lines @@
                     (time - base::TimeTicks()).InSecondsF());
   }
 
   size_t clients_size_for_testing() const { return clients_.size(); }
   size_t pending_clients_size_for_testing() const {
     return pending_clients_.size();
   }
 
  private:
   void CompleteInitializationInternal(MidiResult result);
+  void AddInitialPorts(MidiManagerClient* client);
 
   // Keeps track of all clients who wish to receive MIDI data.
   typedef std::set<MidiManagerClient*> ClientSet;
   ClientSet clients_;
 
   // Keeps track of all clients who are waiting for CompleteStartSession().
   ClientSet pending_clients_;
 
   // Keeps a SingleThreadTaskRunner of the thread that calls StartSession in
   // order to invoke CompleteStartSession() on the thread.
   scoped_refptr<base::SingleThreadTaskRunner> session_thread_runner_;
 
   // Keeps true if platform dependent initialization is already completed.
   bool initialized_;
 
   // Keeps the platform dependent initialization result if initialization is
   // completed. Otherwise keeps MIDI_NOT_SUPPORTED.
   MidiResult result_;
 
-  // Protects access to |clients_|, |pending_clients_|, |initialized_|, and
-  // |result_|.
-  base::Lock lock_;
-
+  // Keeps all MidiPortInfo.
   MidiPortInfoList input_ports_;
   MidiPortInfoList output_ports_;
 
+  // Protects access to |clients_|, |pending_clients_|, |initialized_|,
+  // |result_|, |input_ports_| and |output_ports_|.
+  base::Lock lock_;
+
   DISALLOW_COPY_AND_ASSIGN(MidiManager);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_MIDI_MIDI_MANAGER_H_