media/midi/usb_midi_descriptor_parser.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_DESCRIPTOR_PARSER_H_
   6 #define MEDIA_MIDI_USB_MIDI_DESCRIPTOR_PARSER_H_
   7
   8 #include <string>
   9 #include <vector>
  10
  11 #include "base/basictypes.h"
  12 #include "media/midi/usb_midi_export.h"
  13 #include "media/midi/usb_midi_jack.h"
  14
  15 namespace media {
  16 namespace midi {
  17
  18 class UsbMidiDevice;
  19
  20 // UsbMidiDescriptorParser parses USB descriptors and
  21 // generates input / output lists of MIDIPortInfo.
  22 // This is not a generic USB descriptor parser: this parser is designed
  23 // for collecting USB-MIDI jacks information from the descriptor.
  24 class USB_MIDI_EXPORT UsbMidiDescriptorParser {
  25  public:
  26   struct DeviceInfo {
  27     DeviceInfo()
  28         : vendor_id(0),
  29           product_id(0),
  30           bcd_device_version(0),
  31           manufacturer_index(0),
  32           product_index(0) {}
  33     uint16 vendor_id;
  34     uint16 product_id;
  35     // The higher one byte represents the "major" number and the lower one byte
  36     // represents the "minor" number.
  37     uint16 bcd_device_version;
  38     uint8 manufacturer_index;
  39     uint8 product_index;
  40
  41     static std::string BcdVersionToString(uint16);
  42   };
  43
  44   UsbMidiDescriptorParser();
  45   ~UsbMidiDescriptorParser();
  46
  47   // Returns true if the operation succeeds.
  48   // When an incorrect input is given, this method may return true but
  49   // never crashes.
  50   bool Parse(UsbMidiDevice* device,
  51              const uint8* data,
  52              size_t size,
  53              std::vector<UsbMidiJack>* jacks);
  54
  55   bool ParseDeviceInfo(const uint8* data, size_t size, DeviceInfo* info);
  56
  57  private:
  58   bool ParseInternal(UsbMidiDevice* device,
  59                      const uint8* data,
  60                      size_t size,
  61                      std::vector<UsbMidiJack>* jacks);
  62   bool ParseDevice(const uint8* data, size_t size, DeviceInfo* info);
  63   bool ParseInterface(const uint8* data, size_t size);
  64   bool ParseCSInterface(UsbMidiDevice* device, const uint8* data, size_t size);
  65   bool ParseEndpoint(const uint8* data, size_t size);
  66   bool ParseCSEndpoint(const uint8* data,
  67                        size_t size,
  68                        std::vector<UsbMidiJack>* jacks);
  69   void Clear();
  70
  71   bool is_parsing_usb_midi_interface_;
  72   uint8 current_endpoint_address_;
  73   uint8 current_cable_number_;
  74
  75   std::vector<UsbMidiJack> incomplete_jacks_;
  76
  77   DISALLOW_COPY_AND_ASSIGN(UsbMidiDescriptorParser);
  78 };
  79
  80 }  // namespace midi
  81 }  // namespace media
  82
  83 #endif  // MEDIA_MIDI_USB_MIDI_DESCRIPTOR_PARSER_H_