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CStringInteractor

Name

CStringInteractor -- Provide an interactor that processes strings.

Synopsis


#include <CStringInteractor.h>
         
 class CStringInteractor {

  CStringInteractor(const std::string& am_sString);
  CStringInteractor(const CStringInteractor& aCStringInteractor);

  ~CStringInteractor();

  const int operator==(const CStringInteractor& aCStringInteractor);
  const std::string getString();
  const int getReadCursor();
  void Rewind();
  virtual int Read(UInt_t nBytes, void* pBuffer);
  virtual int Write(UInt_t nBytes, void* pBuffer);
}

Description

String interactors allow you to treat strings gotten by whatever means as sources for interactors. Note that writes to a string interactor are not errors, they just don't do anything. This makes string interactors behave consistently if used as interactive entitites.

While string interactors behave exactly like any other interactor, they have additional member functions that recognize their string nature.

Public member functions

CStringInteractor(const std::string& am_sString);

Constructs a string interactor given a string am_sString. The string will be the data 'read' by the interactor.

CStringInteractor(const CStringInteractor& aCStringInteractor);

Constructs a string interactor that is an exact state duplicate of aCStringInteractor. The duplication extends not only to the string but to the position within the string from which data will be returned to satisfy read operations (the cursor).

~CStringInteractor();

Releases all storage and resources required by the interactor prior to its finaly destruction.

const int operator==(const CStringInteractor& aCStringInteractor);

Assignment operator. The object will become an exact duplicate of the aCStringInteractor. This duplication extends to the cursor.

const std::string getString();

Informational method that returns the full string managed by the interactor.

const int getReadCursor();

Informational method that returns the read cursor. The read is the offset into the string managed by the interactor from which the next read will be satisfied. If, for example, an interactor *interactor was constructed on the string astring, the first character of the next read will be astring[interactor->getReadCursor()]

void Rewind();

Resets the read cursor to zero, allowing the string to be re-read.

virtual int Read(UInt_t nBytes, void* pBuffer);

Returns data from the string. At most nBytes of data are read beginning at the read cursor. If there are fewer, than nBytes of data left in the string, the entire remainder of the string is read. The data is copied from the string to pBuffer. The number of bytes actually read is returned as the method's function value.

After the read has been completed, the read cursor is advanced by the number of bytes returned. If there are no more bytes available in the string, the function will return 0 and no data will be transfered to pBuffer

virtual int Write(UInt_t nBytes, void* pBuffer);

This function simply returns the value of nBytes. This simulates successful completion of the write, although no data will actually be transferred.

EXAMPLES

This example shows how to determine that an interactor is a string interactor and if so, rewind it:

Example 1. Calling CStringInteractor specific members


CInteractor*       pAnInteractor = getInteractor();
...
CStringIteractor*  pString       =
         dynamic_cast<CStringInteractor*>(pAnInteractor);
if (pString) {
   pString->Rewind(); 
}
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