MultipleChoiceQuestion.h

Go to the documentation of this file.

/* ES40 emulator.
 * Copyright (C) 2007-2008 by the ES40 Emulator Project
 *
 * WWW    : http://sourceforge.net/projects/es40
 * E-mail : camiel@camicom.com
 * 
 * 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 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.
 *
 * Although this is not required, the author would appreciate being notified of, 
 * and receiving any modifications you may make to the source code that might serve
 * the general public.
 */

class Answer
{
public:
  Answer(string answer, string value, string explanation)
  {
    mAnswer = answer;
    mValue = value;
    mExplanation = explanation;
  }

  bool operator == (string x)
  {
    return (mAnswer == x);
  }
  string getAnswer() 
  { 
    return mAnswer; 
  }

  string getValue() 
  { 
    return mValue; 
  }

  string getExplanation() 
  { 
    return mExplanation; 
  }
protected:
  string mAnswer;

  string mValue;

  string mExplanation;
};

typedef vector<Answer> AnswerSet;

class MultipleChoiceQuestion: public FreeTextQuestion
{
public:
  void addAnswer(string answer, string value, string explanation)
  {
    mAnswerSet.push_back(Answer(answer,value,explanation));
  }

  virtual void explain()
  {
    AnswerSet::iterator itAnswers;

    /* Explain the quistion as usual.
     */
    FreeTextQuestion::explain();
    
    /* Explain the allowed answers.
     */
    cout << "POSSIBLE VALUES:\n";

    /* Iterate through the answer set.
     */
    for(itAnswers = mAnswerSet.begin(); itAnswers != mAnswerSet.end(); itAnswers++)
    {
      /* Print the answer and its explanation.
       */
      cout << itAnswers->getAnswer() << "\t\t" << itAnswers->getExplanation() << "\n";
    }
    cout << "\n";
  }

  size_t countAnswers() 
  { 
    return mAnswerSet.size(); 
  }

  virtual string ask()
  {
    AnswerSet::iterator itAnswers;
    string options;

    /* Iterate through the answer set to create the 
     * options list.
     */
     
    for(itAnswers = mAnswerSet.begin(); itAnswers != mAnswerSet.end(); itAnswers++)
    {
      if (options != "")
        options += ",";
      options += itAnswers->getAnswer();
    }

    /* Set the options list.
     */
    setOptions(options);

    /* Keep repeating the question until a valid
     * answer is received.
     */
    for (;;)
    {
      /* Ask the question as a FreeTextQuestion. This
       * takes care of the explanation and default
       * value handling.
       */
      FreeTextQuestion::ask();

      /* Try to find the answer received in the answer
       * set.
       */
      itAnswers = find(mAnswerSet.begin(), mAnswerSet.end(), mAnswer);

      /* Has a matching answer be found?
       */
      if (itAnswers != mAnswerSet.end())
      {
        /* Get the value for the received answer.
         */
        string value = itAnswers->getValue();
        haveChosen(mAnswer);
        mAnswer = value;

        /* Return the value.
         */
        return mAnswer;
      }

      /* No valid, matching answer received.
       */
      cout << "\nPlease enter a valid value, or '?' for help.\n\n";
    }
  };

  void dropChoice(string choice)
  {
    AnswerSet::iterator itAnswers;

    /* Try to find the answer in the answer set.
     */
    itAnswers = find(mAnswerSet.begin(), mAnswerSet.end(), mAnswer);

    /* Has a matching answer be found?
     */
    if (itAnswers != mAnswerSet.end())
    {
      /* Delete the answer from the list.
       */
      mAnswerSet.erase(itAnswers);
    }
  }

  virtual void haveChosen(string choice) 
  {
  }

  string getFirstChoice()
  {
    return mAnswerSet.begin()->getAnswer();
  }
protected:
  AnswerSet mAnswerSet;
};

Project space on SourceForge.net