BaseUsbProWidget.h

/*
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Library General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * BaseUsbProWidget.h
 * Read and Write to a USB Serial Widget that uses the Enttec Usb Pro frame
 * layout.
 * Copyright (C) 2010 Simon Newton
 */

#ifndef PLUGINS_USBPRO_BASEUSBPROWIDGET_H_
#define PLUGINS_USBPRO_BASEUSBPROWIDGET_H_

#include <stdint.h>
#include <string>
#include "ola/Callback.h"
#include "ola/DmxBuffer.h"
#include "ola/io/Descriptor.h"
#include "plugins/usbpro/SerialWidgetInterface.h"

namespace ola {
namespace plugin {
namespace usbpro {


/*
 * A widget that implements the Usb Pro frame format.
 */
class BaseUsbProWidget: public SerialWidgetInterface {
 public:
  explicit BaseUsbProWidget(ola::io::ConnectedDescriptor *descriptor);
  virtual ~BaseUsbProWidget();

  ola::io::ConnectedDescriptor *GetDescriptor() const {
    return m_descriptor;
  }
  void DescriptorReady();

  // we locate the SendDMX in the base class since so many widgets share it.
  virtual bool SendDMX(const DmxBuffer &buffer);

  bool SendMessage(uint8_t label,
                   const uint8_t *data,
                   unsigned int length) const;

  static ola::io::ConnectedDescriptor *OpenDevice(const std::string &path);

  static const uint8_t DEVICE_LABEL = 78;
  static const uint8_t DMX_LABEL = 6;
  static const uint8_t GET_PARAMS = 3;
  static const uint8_t HARDWARE_VERSION_LABEL = 14;
  static const uint8_t MANUFACTURER_LABEL = 77;
  static const uint8_t SERIAL_LABEL = 10;

 private:
  typedef enum {
    PRE_SOM,
    RECV_LABEL,
    RECV_SIZE_LO,
    RECV_SIZE_HI,
    RECV_BODY,
    RECV_EOM,
  } receive_state;

  enum {MAX_DATA_SIZE = 600};

  typedef struct {
    uint8_t som;
    uint8_t label;
    uint8_t len;
    uint8_t len_hi;
  } message_header;

  ola::io::ConnectedDescriptor *m_descriptor;
  receive_state m_state;
  unsigned int m_bytes_received;
  message_header m_header;
  uint8_t m_recv_buffer[MAX_DATA_SIZE];

  void ReceiveMessage();
  virtual void HandleMessage(uint8_t label,
                             const uint8_t *data,
                             unsigned int length) = 0;

  static const uint8_t EOM = 0xe7;
  static const uint8_t SOM = 0x7e;
  static const unsigned int HEADER_SIZE;
};


class DispatchingUsbProWidget: public BaseUsbProWidget {
 public:
  typedef ola::Callback3<void,
                         uint8_t,
                         const uint8_t*,
                         unsigned int> MessageCallback;
  DispatchingUsbProWidget(ola::io::ConnectedDescriptor *descriptor,
                          MessageCallback *callback)
      : BaseUsbProWidget(descriptor),
        m_callback(callback) {
  }

  ~DispatchingUsbProWidget() {
    Stop();
  }

  void Stop() {
    if (m_callback)
      delete m_callback;
  }

  void SetHandler(MessageCallback *callback) {
    if (m_callback)
      delete m_callback;
    m_callback = callback;
  }

 private:
  MessageCallback *m_callback;

  void HandleMessage(uint8_t label,
                     const uint8_t *data,
                     unsigned int length) {
    m_callback->Run(label, data, length);
  }
};
}  // namespace usbpro
}  // namespace plugin
}  // namespace ola
#endif  // PLUGINS_USBPRO_BASEUSBPROWIDGET_H_