Question for Hadyn

BagInterface.java

/*
Name: Gino Di Gregorio

Project Name: CSC400-Module 2 Clothing Boutique

Project Purpose: Understanding working with bags by implementing a class that implements a baginterface class

Algorithm Used: implementing a class called ClothingBag that implements the BagInterface<MyType>

Program Inputs:

Program Outputs:

Program Limitations:

Program Errors:

 */

public interface BagInterface<MyType> {

	//adds a new entry and returns true or false depending if the addition completed or not
	public boolean add(MyType newEntry);
	
	//removes a specific entry and returns true or false depending if the removal completed or not
	public boolean remove(MyType newEntry);
	
	//removes an arbitrary entry and returns true or false depending if the removal completed or not
	public boolean remove();
	
	//checks if bag is empty
	public boolean isEmpty();
	
	//removes all entries from bag
	public void clear();
	
	//returns current number of entries in bag
	public int getCurrentSize();
	
	//tests if the bag contains a specific entry
	public boolean contains(MyType anEntry);
	
	//stores all entries in an array
	public MyType[] toArray();
}

BoutiqueBagDemo

/*
Name: Gino Di Gregorio

Project Name: CSC400-Module 2 Clothing Boutique

Project Purpose: Understanding working with bags by implementing a class that implements a baginterface class

Algorithm Used: implementing a class called ClothingBag that implements the BagInterface<MyType>

Program Inputs:

Program Outputs:

Program Limitations:

Program Errors:

 */

public class BoutiqueBagDemo {

	public static void main(String[] args){
		ClothingBag(10);
		
	}
	
}

ClothingBag.java

import java.util.Arrays;

/*
Name: Gino Di Gregorio

Project Name: CSC400-Module 2 Clothing Boutique

Project Purpose: Understanding working with bags by implementing a class that implements a baginterface class

Algorithm Used: implementing a class called ClothingBag that implements the BagInterface<MyType>

Program Inputs:

Program Outputs:

Program Limitations:

Program Errors:

 */

public class ClothingBag<MyType> implements BagInterface<MyType> {

	MyType[] bag;
	int numberOfEntries;
	int size;
	static final int DEFAULT_SIZE = 2;
	static final int MAX_SIZE = 500;
	
	//create default bag with default size
	public ClothingBag(){
		this(DEFAULT_SIZE);
	}
	
	//create bag with specific size
	public ClothingBag(int size) {
		checkSize(size);
		MyType[] tempBag = (MyType[])new Object[size];
		bag = tempBag;
		numberOfEntries = 0;
	}

	public ClothingBag(MyType[] contents) {
		checkSize(contents.length);
		bag = Arrays.copyOf(contents, contents.length);
		numberOfEntries = contents.length;
	}
	
	private void checkSize(int size) {
		if(size > MAX_SIZE)
			throw new IllegalStateException("Desired bag size exceeds maximum bag size of " + MAX_SIZE);
	}

	//adds a new entry to bag
	@Override
	public boolean add(MyType newEntry) {
		// TODO Auto-generated method stub
		if(isArrayFull()) {
			doubleSize();
		}
		bag[numberOfEntries] = newEntry;
		numberOfEntries++;
		return true;
	}
	
	private void doubleSize() {
		int newLength = 2 * bag.length;
		checkSize(newLength);
		bag = Arrays.copyOf(bag, newLength);
	}

	//removes one instance of specified entry
	@Override
	public boolean remove(MyType newEntry) {
		// TODO Auto-generated method stub
		int index = getIndexOf(newEntry);
		MyType result = removeEntry(index);
		return newEntry.equals(result);
	}

	//removes random entry
	@Override
	public MyType remove() {
		// TODO Auto-generated method stub
		MyType result = removeEntry(numberOfEntries - 1);
		return result;
	}
	
	private MyType removeEntry(int givenIndex) {
		MyType result = null;
		if(!isEmpty() && givenIndex >= 0) {
			result = bag[givenIndex];
			int lastIndex = numberOfEntries - 1;
			bag[givenIndex] = bag[lastIndex];
			bag[lastIndex] = null;
			numberOfEntries--;
		}
		return result;
	}

	//tests if bag is empty
	@Override
	public boolean isEmpty() {
		// TODO Auto-generated method stub
		return numberOfEntries == 0;
	}

	//removes all entries in bag
	@Override
	public void clear() {
		// TODO Auto-generated method stub
		while(!isEmpty())
			remove();
	}

	//returns current number of entries in bag
	@Override
	public int getCurrentSize() {
		// TODO Auto-generated method stub
		return numberOfEntries;
	}

	//tests if bag contains a certain entry
	@Override
	public boolean contains(MyType anEntry) {
		// TODO Auto-generated method stub
		return getIndexOf(anEntry) > -1;
	}

	private boolean isArrayFull() {
		return numberOfEntries >= bag.length;
	}
	
	//stores all entries in bag to an array
	@Override
	public MyType[] toArray() {
		// TODO Auto-generated method stub
		MyType[] result = (MyType[])new Object[numberOfEntries];
		for(int index = 0; index < numberOfEntries; index++) {
			result[index] = bag[index];
		}
		return result;
	}

	private int getIndexOf(MyType anEntry){
		int where = -1;
		boolean found = false;
		int index = 0;
		
		while(!found && (index < numberOfEntries)) {
			if(anEntry.equals(bag[index])) {
				found = true;
				where = index;
			}
			index++;
		}
		return where;
	}
	
}