// If there was a package statement, it would go here.

// If any import statements existed they would go here.

/**
 * Project #1
 * CS 2334, Section 010
 * Feb 3, 2011
 * <P>
 * This is an example class for CS 2334 that shows proper
 * documentation. It is a class that doesn't do much of anything
 * useful, which makes it hard to write a really great comment up
 * here. It is however, properly documented.  
 * </P>
 * @version 4.0
 */
public class MyString {

    /**
     * A constant that contains the standard number of
     * characters in a string.
     */
    static public int DEFAULT_SIZE = 10;

    /** A private array to store the characters in the string. */
    private char[] data;

    /** 
     * The number of characters that are actually stored in the
     * string. 
     */
    private int size;

    /**
     * A constructor for an empty string of
     * <code>currentSize</code> elements.  
     *
     * @param     currentSize    The number of characters in the
     *                   string.
     * @throws    IllegalArgumentException    if currentSize < 0
     * <dt><b>Conditions:</b>
     * <dd>PRE  -     <code>currentSize</code> contains a non-negative
     *        integer.
     * <dd>POST -     The character array data is of length
     *        <code>currentSize</code>.
     */
    public MyString( int currentSize ) {
        /* Test preconditions. 
         * In public methods, preconditions are tested with an "if" 
         * statement that throws an IllegalArgumentException if the 
         * the condition fails. In private classes, preconditions
         * can be tested using "assert" statements.
         */
        if( currentSize < 0 ) {
            throw new IllegalArgumentException( 
                "Illegal currentSize: " + currentSize );
        }

        data = new char[currentSize];
        size = 0; // Set the number of characters stored to zero.

        /* Test postconditions. 
         * In all methods, postconditions are tested using "assert"
         * statements.
         */
        assert (data.length == currentSize);
    } // end MyString

    /**
     * An accessor for the variable <code>size</code>.
     *
     * @return    The number of characters in the current string.
     */
    public int getLength() {
        return size;
    } // end getLength

    /**
     * The accessor for the character array <code>data</code>.
     *
     * @return    A reference to the array <code>data</code>.
     */
    public char[] getData() {
        return data;
    } // end getData

    /**
     * A mutator that sets the size of the array. This is a simple
     * method, so it does not have a very sophisticated algorithm.
     * <P>
     * Algorithm:<br>
     * 1. Allocate more space.<br>
     * 2. Copy existing data into the new array.<br>
     * 3. Record changes in the instance variables.<br>
     * </P>
     * @param     newLength    The desired length for the modified
     *                 string.
     * @throws    IllegalArgumentException    if newLength < 0
     * <dt><b>Conditions:</b>
     * <dd>PRE  -      <code>newLength</code> contains a non-negative
     *        integer.
     * <dd>POST -     The character array data is of length
     *        <code>newLength</code>.
     */
    public void setLength( int newLength ) {
        /* Test preconditions. */
        if( newLength < 0 ) {
            throw new IllegalArgumentException( 
                "Illegal newLength: " + newLength );
        }

        /* 
         * Contains the number of characters in the string after it
         * has been re-sized.
         */
        int newSize; 

        // Allocate more space.
        char[] newData = new char[newLength];

        // Copy existing data into the new array.
        for( int i = 0; i< Math.min( newLength, size ); i++ ) {
            newData[i] = data[i];
        } // end for

        // Record changes in the instance variables.
        data = newData;
        size = Math.min( newLength, size );

        /* Test postconditions. */
        assert (data.length == newLength);
    } // end setLength

    /**
     * A mutator that changes the contents of the character array
     * <code>data</code>.
     *
     * @param    newData    A reference to the character array to be
     *              used.
     * <dt><b>Conditions:</b>
     * <dd>PRE  -    The character array data has the same length as
     *           <code>newData</code>.
     * <dd>POST -    Both data and newData refer to the same character
     *           array.
     */
    public void setData( char[] newData ) {
        /* 
         * Set data to refer to the character referenced by
         * newData.
         */
        data = newData;
        size = data.length;

        /* Test postconditions. */
        assert (data.length == newData.length);
        assert (data == newData);

    } // end setData

} // End of class MyString