Web MIDI: implement receiving for dynamic manager instantiation on Windows

media/midi/dynamically_initialized_midi_manager_win.h

 // Copyright 2017 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_DYNAMICALLY_INITIALIZED_MIDI_MANAGER_WIN_H_
 #define MEDIA_MIDI_DYNAMICALLY_INITIALIZED_MIDI_MANAGER_WIN_H_
 
 #include <memory>
 #include <vector>
 
 #include "base/callback_forward.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/system_monitor/system_monitor.h"
 #include "media/midi/midi_manager.h"
 
 namespace base {
 class SingleThreadTaskRunner;
 }  // namespace base
 
 namespace midi {
 
 // New backend for legacy Windows that support dynamic instantiation.
 class DynamicallyInitializedMidiManagerWin final
     : public MidiManager,
       public base::SystemMonitor::DevicesChangedObserver {
  public:
+  class PortManager;
+
   explicit DynamicallyInitializedMidiManagerWin(MidiService* service);
   ~DynamicallyInitializedMidiManagerWin() override;
 
-  // Posts a reply task to the I/O thread that hosts MidiManager instance, runs
-  // it safely, and ensures that the instance keeps alive while the task is
-  // running.
-  void PostReplyTask(const base::Closure&);
+  // Returns PortManager that implements interfaces to help implementation.
+  // This hides Windows specific structures, i.e. HMIDIIN in the header.
+  PortManager* port_manager() { return port_manager_.get(); }
 
   // MidiManager overrides:
   void StartInitialization() override;
   void Finalize() override;
   void DispatchSendMidiData(MidiManagerClient* client,
                             uint32_t port_index,
                             const std::vector<uint8_t>& data,
                             double timestamp) override;
 
   // base::SystemMonitor::DevicesChangedObserver overrides:
   void OnDevicesChanged(base::SystemMonitor::DeviceType device_type) override;
 
  private:
   class InPort;
   class OutPort;
 
+  // Handles MIDI inport event posted from a thread system provides.
+  void ReceiveMidiData(uint32_t index,
+                       const std::vector<uint8_t>& data,
+                       base::TimeTicks time);
+
   // Posts a task to TaskRunner, and ensures that the instance keeps alive while
   // the task is running.
   void PostTask(const base::Closure&);
 
+  // Posts a reply task to the I/O thread that hosts MidiManager instance, runs
+  // it safely, and ensures that the instance keeps alive while the task is
+  // running.
+  void PostReplyTask(const base::Closure&);
+
   // Initializes instance asynchronously on TaskRunner.
   void InitializeOnTaskRunner();
 
   // Updates device lists on TaskRunner.
   // Returns true if device lists were changed.
   void UpdateDeviceListOnTaskRunner();
 
   // Reflect active port list to a device list.
   template <typename T>
   void ReflectActiveDeviceList(DynamicallyInitializedMidiManagerWin* manager,
                                std::vector<T>* known_ports,
                                std::vector<T>* active_ports);
 
   // Holds an unique instance ID.
   const int instance_id_;
 
   // Keeps a TaskRunner for the I/O thread.
   scoped_refptr<base::SingleThreadTaskRunner> thread_runner_;
 
-  // Following members should be accessed only on TaskRunner.
-
-  // Holds all MIDI input or output ports connected once.
-  std::vector<std::unique_ptr<InPort>> input_ports_;
-  std::vector<std::unique_ptr<OutPort>> output_ports_;
+  // Manages platform dependent implementation for port managegent. Should be
+  // accessed with the task lock.
+  std::unique_ptr<PortManager> port_manager_;
 
   DISALLOW_COPY_AND_ASSIGN(DynamicallyInitializedMidiManagerWin);
 };
 
 }  // namespace midi
 
 #endif  // MEDIA_MIDI_DYNAMICALLY_INITIALIZED_MIDI_MANAGER_WIN_H_