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 <vector>
   9
  10 #include "base/basictypes.h"
  11 #include "media/base/media_export.h"
  12 #include "media/midi/usb_midi_jack.h"
  13
  14 namespace media {
  15
  16 class UsbMidiDevice;
  17
  18 // UsbMidiDescriptorParser parses USB descriptors and
  19 // generates input / output lists of MIDIPortInfo.
  20 // This is not a generic USB descriptor parser: this parser is designed
  21 // for collecting USB-MIDI jacks information from the descriptor.
  22 class MEDIA_EXPORT UsbMidiDescriptorParser {
  23  public:
  24   UsbMidiDescriptorParser();
  25   ~UsbMidiDescriptorParser();
  26
  27   // Returns true if the operation succeeds.
  28   // When an incorrect input is given, this method may return true but
  29   // never crashes.
  30   bool Parse(UsbMidiDevice* device,
  31              const uint8* data,
  32              size_t size,
  33              std::vector<UsbMidiJack>* jacks);
  34
  35  private:
  36   bool ParseInternal(UsbMidiDevice* device,
  37                      const uint8* data,
  38                      size_t size,
  39                      std::vector<UsbMidiJack>* jacks);
  40   bool ParseInterface(const uint8* data, size_t size);
  41   bool ParseCSInterface(UsbMidiDevice* device, const uint8* data, size_t size);
  42   bool ParseEndpoint(const uint8* data, size_t size);
  43   bool ParseCSEndpoint(const uint8* data,
  44                        size_t size,
  45                        std::vector<UsbMidiJack>* jacks);
  46   void Clear();
  47
  48   bool is_parsing_usb_midi_interface_;
  49   uint8 current_endpoint_address_;
  50   uint8 current_cable_number_;
  51
  52   std::vector<UsbMidiJack> incomplete_jacks_;
  53
  54   DISALLOW_COPY_AND_ASSIGN(UsbMidiDescriptorParser);
  55 };
  56
  57
  58 }  // namespace media
  59
  60 #endif  // MEDIA_MIDI_USB_MIDI_DESCRIPTOR_PARSER_H_