media/midi/usb_midi_device.h

   1 // Copyright 2014 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 #ifndef MEDIA_MIDI_USB_MIDI_DEVICE_H_
   6 #define MEDIA_MIDI_USB_MIDI_DEVICE_H_
   7
   8 #include <vector>
   9
  10 #include "base/basictypes.h"
  11 #include "base/callback.h"
  12 #include "base/memory/scoped_vector.h"
  13 #include "base/time/time.h"
  14 #include "media/base/media_export.h"
  15
  16 namespace media {
  17
  18 class MidiManagerUsb;
  19 class UsbMidiDevice;
  20
  21 // Delegate class for UsbMidiDevice.
  22 // Each method is called when an corresponding event arrives at the device.
  23 class MEDIA_EXPORT UsbMidiDeviceDelegate {
  24  public:
  25   virtual ~UsbMidiDeviceDelegate() {}
  26
  27   // Called when USB-MIDI data arrives at |device|.
  28   virtual void ReceiveUsbMidiData(UsbMidiDevice* device,
  29                                   int endpoint_number,
  30                                   const uint8* data,
  31                                   size_t size,
  32                                   base::TimeTicks time) = 0;
  33
  34   // Called when a USB-MIDI device is attached.
  35   virtual void OnDeviceAttached(scoped_ptr<UsbMidiDevice> device) = 0;
  36   // Called when a USB-MIDI device is detached.
  37   virtual void OnDeviceDetached(size_t index) = 0;
  38 };
  39
  40 // UsbMidiDevice represents a USB-MIDI device.
  41 // This is an interface class and each platform-dependent implementation class
  42 // will be a derived class.
  43 class MEDIA_EXPORT UsbMidiDevice {
  44  public:
  45   typedef ScopedVector<UsbMidiDevice> Devices;
  46
  47   // Factory class for USB-MIDI devices.
  48   // Each concrete implementation will find and create devices
  49   // in platform-dependent way.
  50   class Factory {
  51    public:
  52     typedef base::Callback<void(bool result, Devices* devices)> Callback;
  53     virtual ~Factory() {}
  54
  55     // Enumerates devices.
  56     // Devices that have no USB-MIDI interfaces can be omitted.
  57     // When the operation succeeds, |callback| will be called with |true| and
  58     // devices.
  59     // Otherwise |callback| will be called with |false| and empty devices.
  60     // When this factory is destroyed during the operation, the operation
  61     // will be canceled silently (i.e. |callback| will not be called).
  62     // This function can be called at most once per instance.
  63     virtual void EnumerateDevices(UsbMidiDeviceDelegate* delegate,
  64                                   Callback callback) = 0;
  65   };
  66
  67   virtual ~UsbMidiDevice() {}
  68
  69   // Returns the descriptor of this device.
  70   virtual std::vector<uint8> GetDescriptor() = 0;
  71
  72   // Sends |data| to the given USB endpoint of this device.
  73   virtual void Send(int endpoint_number, const std::vector<uint8>& data) = 0;
  74 };
  75
  76 }  // namespace media
  77
  78 #endif  // MEDIA_MIDI_USB_MIDI_DEVICE_H_