ELClientResponse.h

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#ifndef _EL_CLIENT_RESPONSE_H_
#define _EL_CLIENT_RESPONSE_H_
 
#if _MSC_VER
#define PACKED
#else
#define PACKED __attribute__ ((__packed__))
#endif
 
#include <Arduino.h>
 
#define VARIABLE_ARG_NUM 255
 
typedef struct PACKED {
  uint16_t cmd;            
  uint16_t argc;           
  uint32_t value;          
  uint8_t  args[0];        
} ELClientPacket; 
// ELClientResponse is a parser for responses. The constructor initializes the parser based on
// a packet and the various pop functions consume one response argument at a time.
class ELClientResponse {
  public:
    // Create a response from a packet, this is done internally in ELClient
    ELClientResponse(ELClientPacket* packet);
    ELClientResponse(void *packet);
 
    // Accessors to the response fields
    uint16_t argc() { return _cmd->argc; } 
    uint16_t cmd() { return _cmd->cmd; } 
    uint32_t value() { return _cmd->value; } 
    // Return the length of the next argument
    uint16_t argLen() { return *(uint16_t*)_arg_ptr; } 
    // Pop one argument from the response, returns the actual length. Returns -1 if there is
    // no arg left.
    int16_t popArg(void* data, uint16_t maxLen);
    // Pop one argument as a poiner from the response, returns the actual length.
    int16_t popArgPtr(void **data);
    // Pop one argument into a string buffer and append a null character. The buffer needs to
    // be large enough (argLen()+1)
    void popChar(char* buffer);
    // Pop one argument into a String buffer
    String popString();
    // Pop one argument into a String buffer
    void popString(String* data);
 
  private:
    uint16_t _arg_num; 
    uint8_t* _arg_ptr; 
    ELClientPacket* _cmd; 
};
 
#endif // _EL_CLIENT_RESPONSE_H_