package Jampack;

/**
   Parameter is a class containing global parameters for
   Jampack.

   @version Pre-alpha
   @author G. W. Stewart
*/

public class Parameters{

/**
   The base index
*/
   protected static int BaseIndex = 1;

/**
   Flag allowing only one change in base index
*/
   protected static boolean BaseIndexNotChangeable;

/**
   Returns the base index
*/

   public static int getBaseIndex()
   {
      return BaseIndex;
   }


/**
   Resets the default base index.
   @param xb     The new base index
   @exception    JampackException
                 Thrown when the base indices are
                 not changable.

*/
   public static void setBaseIndex(int bx)
   throws JampackException{
      if (BaseIndexNotChangeable){
         throw new JampackException
            ("Illegal attempt to change base index");
      }
      BaseIndex = bx;
      BaseIndexNotChangeable = true;
   }

/**
   Adjust the base index of a Zmat to make it conform to
   the default.
*/
   public static void adjustBaseIndex(Zmat A){
      BaseIndexNotChangeable = true;
      A.basex = BaseIndex;
      A.getProperties();
   }

/**
   Adjust the base index of a Zdiagmat to make it conform to
   the default.
*/
   public static void adjustBaseIndex(Zdiagmat A){
      BaseIndexNotChangeable = true;
      A.basex = BaseIndex;
      A.getProperties();
   }

/**
   The history flag indicating whether to save decompositions
*/

   protected static boolean History = true;

/**
   Sets the history flag.
*/
   public static void setHistory(){
      History = true;
  }

/**
   Unsets the history flag.
*/
   public static void unsetHistory(){
      History = false;
  }

/**
   Output field width.
*/   
   protected static int OutputFieldWidth = 12;
/**
   Number of places to the right of the decimal point.
*/
   protected static int OutputFracPlaces = 3;
/**
   Output page width
*/
   protected static int PageWidth = 80;

/**
   Changes the output parameters.  Nonpositive parameters are ignored.
   @param width      The new field width
   @param frac       The new number of places to the right of the decimal
   @param pagewidth  The new page width
*/
   public static void setOutputParams(int width, int frac, int pagewidth){

      OutputFieldWidth = (width>0)? width: OutputFieldWidth;
      OutputFracPlaces = (frac>0)? width: OutputFracPlaces;
      PageWidth = (pagewidth>0)? pagewidth: PageWidth;
   }
}