//--------------------------------------------------------------------
//
//  Laboratory 2                                         ptlist.C
//
//  SOLUTION: Array implementation of the Point List ADT
//
//--------------------------------------------------------------------

#include <assert.h>
#include <iostream.h>
#include <math.h>
#include "ptlist.h"

//--------------------------------------------------------------------

PointList:: PointList ( int maxNumber )

// Creates an empty list. Allocates enough memory for maxNumber
// points (defaults to defMaxListSize).

  : maxSize(maxNumber),
    size(0),
    cursor(-1)
{
    ptlist = new Point [ maxSize ];
    assert ( ptlist != 0 );
}

//--------------------------------------------------------------------

PointList:: ~PointList ()

// Frees the memory used by a list.

{
    delete [] ptlist;
}

//--------------------------------------------------------------------

void PointList:: append ( Point newPoint )

// Appends newPoint to a list. If the list is empty, then newPoint is
// inserted as the first (and only) point in the list. Moves the
// cursor to newPoint.

{
    int j;   // Loop counter

    assert ( size < maxSize );    // Requires that list is not full
    cursor = size++;
    ptlist[cursor] = newPoint;
}

//--------------------------------------------------------------------

void PointList:: clear ()

// Removes all the points from a list.

{
    size = 0;
}

//--------------------------------------------------------------------

int PointList:: empty () const

// Returns 1 if a list is empty. Otherwise, returns 0.

{
    return ( size == 0 );
}

//--------------------------------------------------------------------

int PointList:: full () const

// Returns 1 if a list is full. Otherwise, returns 0.

{
    return ( size == maxSize );
}

//--------------------------------------------------------------------

Point PointList:: getCursor () const

// Returns the point marked by the cursor.

{
    assert ( size != 0 );      // Requires that the list is not empty
    return ptlist[cursor];
}

//--------------------------------------------------------------------

int PointList:: gotoBeginning ()

// If a list is not empty, then moves the cursor to the beginning of
// the list and returns 1. Otherwise, returns 0.

{
    int result;   // Result returned

    if ( size != 0 )
    {
       cursor = 0;
       result = 1;
    }
    else
       result = 0;

    return result;
}

//--------------------------------------------------------------------

int PointList:: gotoEnd ()

// If a list is not empty, then moves the cursor to the end of the
// list and returns 1. Otherwise, returns 0.

{
    int result;   // Result returned

    if ( size != 0 )
    {
       cursor = size - 1;
       result = 1;
    }
    else
       result = 0;

    return result;
}

//--------------------------------------------------------------------

int PointList:: gotoNext ()

// If the cursor is not at the end of a list, then moves the cursor
// to the next point in the list and returns 1. Otherwise, returns 0.

{
    int result;   // Result returned

    if ( cursor != size-1 )
    {
       cursor++;
       result = 1;
    }
    else
       result = 0;

    return result;
}

//--------------------------------------------------------------------

int PointList:: gotoPrior ()

// If the cursor is not at the beginning of a list, then moves the
// cursor to the preceeding point in the list and returns 1.
// Otherwise, returns 0.

{
    int result;   // Result returned

    if ( cursor != 0 )
    {
       cursor--;
       result = 1;
    }
    else
       result = 0;

    return result;
}

//--------------------------------------------------------------------

void PointList:: showStructure () const

// Outputs the points in a list. If the list is empty, outputs
// "Empty list". This operation is intended for testing/debugging
// purposes only.

{
    int j;   // Loop counter

    if ( size == 0 )
       cout << "Empty list" << endl;
    else
    {
       cout << "size = " << size
            <<  "   cursor = " << cursor << endl;
       for ( j = 0 ; j < maxSize ; j++ )
           cout << j << "\t";
       cout << endl;
       for ( j = 0 ; j < size ; j++ )
           cout << "(" << ptlist[j].x << ","
                       << ptlist[j].y << ")\t";
       cout << endl;
    }
}