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 "base/time/time.h"
  14 #include "media/midi/usb_midi_export.h"
  15 #include "media/midi/usb_midi_jack.h"
  16
  17 namespace media {
  18 namespace midi {
  19
  20 class UsbMidiDevice;
  21
  22 // UsbMidiInputStream converts USB-MIDI data to MIDI data.
  23 // See "USB Device Class Definition for MIDI Devices" Release 1.0,
  24 // Section 4 "USB-MIDI Event Packets" for details.
  25 class USB_MIDI_EXPORT UsbMidiInputStream {
  26  public:
  27   class USB_MIDI_EXPORT Delegate {
  28    public:
  29     virtual ~Delegate() {}
  30     // This function is called when some data arrives to a USB-MIDI jack.
  31     // An input USB-MIDI jack corresponds to an input MIDIPortInfo.
  32     virtual void OnReceivedData(size_t jack_index,
  33                                 const uint8* data,
  34                                 size_t size,
  35                                 base::TimeTicks time) = 0;
  36   };
  37
  38   // This is public for testing.
  39   struct JackUniqueKey {
  40     JackUniqueKey(UsbMidiDevice* device, int endpoint_number, int cable_number);
  41     bool operator==(const JackUniqueKey& that) const;
  42     bool operator<(const JackUniqueKey& that) const;
  43
  44     UsbMidiDevice* device;
  45     int endpoint_number;
  46     int cable_number;
  47   };
  48
  49   explicit UsbMidiInputStream(Delegate* delegate);
  50   ~UsbMidiInputStream();
  51
  52   void Add(const UsbMidiJack& jack);
  53
  54   // This function should be called when some data arrives to a USB-MIDI
  55   // endpoint. This function converts the data to MIDI data and call
  56   // |delegate->OnReceivedData| with it.
  57   // |size| must be a multiple of |kPacketSize|.
  58   void OnReceivedData(UsbMidiDevice* device,
  59                       int endpoint_number,
  60                       const uint8* data,
  61                       size_t size,
  62                       base::TimeTicks time);
  63
  64   const std::vector<UsbMidiJack>& jacks() const { return jacks_; }
  65
  66  private:
  67   static const size_t kPacketSize = 4;
  68   // Processes a USB-MIDI Event Packet.
  69   // The first |kPacketSize| bytes of |packet| must be accessible.
  70   void ProcessOnePacket(UsbMidiDevice* device,
  71                         int endpoint_number,
  72                         const uint8* packet,
  73                         base::TimeTicks time);
  74
  75   std::vector<UsbMidiJack> jacks_;
  76   // A map from UsbMidiJack to its index in |jacks_|.
  77   std::map<JackUniqueKey, size_t> jack_dictionary_;
  78
  79   // Not owned
  80   Delegate* delegate_;
  81
  82   DISALLOW_COPY_AND_ASSIGN(UsbMidiInputStream);
  83 };
  84
  85 }  // namespace midi
  86 }  // namespace media
  87
  88 #endif  // MEDIA_MIDI_USB_MIDI_INPUT_STREAM_H_