media/midi/usb_midi_input_stream.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_INPUT_STREAM_H_
   6 #define MEDIA_MIDI_USB_MIDI_INPUT_STREAM_H_
   7
   8 #include <map>
   9 #include <vector>
  10
  11 #include "base/basictypes.h"
  12 #include "base/containers/hash_tables.h"
  13 #include "media/base/media_export.h"
  14 #include "media/midi/usb_midi_jack.h"
  15
  16 namespace media {
  17
  18 class UsbMidiDevice;
  19
  20 // UsbMidiInputStream converts USB-MIDI data to MIDI data.
  21 // See "USB Device Class Definition for MIDI Devices" Release 1.0,
  22 // Section 4 "USB-MIDI Event Packets" for details.
  23 class MEDIA_EXPORT UsbMidiInputStream {
  24  public:
  25   class MEDIA_EXPORT Delegate {
  26    public:
  27     virtual ~Delegate() {}
  28     // This function is called when some data arrives to a USB-MIDI jack.
  29     // An input USB-MIDI jack corresponds to an input MIDIPortInfo.
  30     virtual void OnReceivedData(size_t jack_index,
  31                                 const uint8* data,
  32                                 size_t size,
  33                                 double timestamp) = 0;
  34   };
  35
  36   // This is public for testing.
  37   struct JackUniqueKey {
  38     JackUniqueKey(UsbMidiDevice* device, int endpoint_number, int cable_number);
  39     bool operator==(const JackUniqueKey& that) const;
  40     bool operator<(const JackUniqueKey& that) const;
  41
  42     UsbMidiDevice* device;
  43     int endpoint_number;
  44     int cable_number;
  45   };
  46
  47   UsbMidiInputStream(const std::vector<UsbMidiJack>& jacks,
  48                      Delegate* delegate);
  49   ~UsbMidiInputStream();
  50
  51   // This function should be called when some data arrives to a USB-MIDI
  52   // endpoint. This function converts the data to MIDI data and call
  53   // |delegate->OnReceivedData| with it.
  54   // |size| must be a multiple of |kPacketSize|.
  55   void OnReceivedData(UsbMidiDevice* device,
  56                       int endpoint_number,
  57                       const uint8* data,
  58                       size_t size,
  59                       double timestamp);
  60
  61   std::vector<JackUniqueKey> RegisteredJackKeysForTesting() const;
  62
  63  private:
  64   static const size_t kPacketSize = 4;
  65   // Processes a USB-MIDI Event Packet.
  66   // The first |kPacketSize| bytes of |packet| must be accessible.
  67   void ProcessOnePacket(UsbMidiDevice* device,
  68                         int endpoint_number,
  69                         const uint8* packet,
  70                         double timestamp);
  71
  72   // A map from UsbMidiJack to its index in |jacks_|.
  73   std::map<JackUniqueKey, size_t> jack_dictionary_;
  74
  75   // Not owned
  76   Delegate* delegate_;
  77
  78   DISALLOW_COPY_AND_ASSIGN(UsbMidiInputStream);
  79 };
  80
  81 }  // namespace media
  82
  83 #endif  // MEDIA_MIDI_USB_MIDI_INPUT_STREAM_H_