//  Created by Frank M. Carrano and Tim Henry.
//  Copyright (c) 2013 __Pearson Education__. All rights reserved.

/** Implementation file for the class ArrayList.
 @file ArrayList.cpp */

#include "ArrayList.h"  // Header file

template<class ItemType>
ArrayList<ItemType>::ArrayList() : itemCount(0), maxItems(DEFAULT_CAPACITY)
{
}  // end default constructor

template<class ItemType>
bool ArrayList<ItemType>::isEmpty() const
{
   return itemCount == 0;
}  // end isEmpty

template<class ItemType>
int ArrayList<ItemType>::getLength() const
{
   return itemCount;
}  // end getLength

template<class ItemType>
bool ArrayList<ItemType>::insert(int newPosition, const ItemType& newEntry)
{
   bool ableToInsert = (newPosition >= 1) && (newPosition <= itemCount + 1) &&             
                       (itemCount < maxItems);
   if (ableToInsert)
   {
      // Make room for new entry by shifting all entries at
      // positions >= newPosition toward the end of the array
      // (no shift if newPosition == itemCount + 1)
      for (int pos = itemCount; pos >= newPosition; pos--)
         items[pos] = items[pos - 1];
         
      // Insert new entry
      items[newPosition - 1] = newEntry;
      itemCount++;  // Increase count of entries
   }  // end if
   
   return ableToInsert;
}  // end insert

template<class ItemType>
bool ArrayList<ItemType>::remove(int position)
{
   bool ableToRemove = (position >= 1) && (position <= itemCount);
   if (ableToRemove)
   {
      // Remove entry by shifting all entries after the one at
      // position toward the beginning of the array
      // (no shift if position == itemCount)
      for (int fromIndex = position, toIndex = fromIndex - 1; fromIndex < itemCount;
	        fromIndex++, toIndex++)
         items[toIndex] = items[fromIndex];
         
      itemCount--;  // Decrease count of entries
   }  // end if
   
   return ableToRemove;
}  // end remove

template<class ItemType>
void ArrayList<ItemType>::clear()
{
   itemCount = 0;
}  // end clear

template<class ItemType>
ItemType ArrayList<ItemType>::getEntry(int position) const throw(PrecondViolatedExcep)
{
   // Enforce precondition
   bool ableToGet = (position >= 1) && (position <= itemCount);
   if (ableToGet)
      return items[position - 1];
   else
   {
      string message = "getEntry() called with an empty list or "; 
      message  = message + "invalid position.";
      throw(PrecondViolatedExcep(message)); 
   }  // end if
}  // end getEntry

template<class ItemType>
void ArrayList<ItemType>::setEntry(int position, const ItemType& newEntry) throw(PrecondViolatedExcep)
{
   // Enforce precondition
   bool ableToSet = (position >= 1) && (position <= itemCount);
   if (ableToSet)
      items[position - 1] = newEntry;
   else
   {
      string message = "setEntry() called with an empty list or "; 
      message  = message + "invalid position.";
      throw(PrecondViolatedExcep(message)); 
   }  // end if
}  // end setEntry

//  End of implementation file.