Attempted Java solution from newbie

From Beautifulcode

(a) Why you believe your solution works ? I've tried my best to synchronize the parent-thread communication

(b) What makes it beautiful ? Not sure about this one :) Will leave it for others to judge.

public abstract class IPlayScrabble extends Thread{
	volatile boolean takeNewTile = false;
	volatile boolean addingWord = false;
	int MAX_TILES;
	int[][] board;
	char[] tiles;
	int lastOpenTile, initialOpenCount;
	Object[] wordPos; //data structure for current word and its position
	Object parent;	
	
	//Subclasses should implement this method. keep checking takeNewTile regularly
	abstract protected Object[] findWordAndPosition(int[][] board, char[] tiles);	
	
	public void takeTile(){
		takeNewTile = true;		
        openNextTile();
        takeNewTile  = false;
	}	
	
	IPlayScrabble(int[][] board, char[] tiles, int initialOpenCount, int maxTiles, Object parent){
		this.board =  board;
		this.tiles = tiles;
		this.MAX_TILES = maxTiles;
		this.lastOpenTile = initialOpenCount;
		this.initialOpenCount = initialOpenCount;
		this.parent = parent;
	}
	
	public void run(){
		while(MAX_TILES - lastOpenTile > 0){
			if(!takeNewTile){				
			    Object[] wordPos = calculateWords();
			    synchronized(this){
			    	if(wordPos != null){			    	    
			    	    if(lastOpenTile >= initialOpenCount){
			    	    	parent.notify();
			    	    	try {
								this.wait();
							} catch (InterruptedException e) {				    	    									
								e.printStackTrace();								
							}
			    	    }
			    	}			    
			    }
			}
		}

	}
	
	private Object[] calculateWords(){
		char[] copy = new char[lastOpenTile];
		System.arraycopy(tiles, 0, copy, 0, lastOpenTile);
		if(!takeNewTile){
		    wordPos = findWordAndPosition(board, copy);
		}
		addingWord = true;
		addWord();		
		if(takeNewTile){
		    undoAddWord();
		    wordPos = null;
		    synchronized(this){
			    lastOpenTile--;
		    }		    
		}else{
	        openNextTile();			
		}
		addingWord = false;
		return wordPos;
	}
	
	private void openNextTile(){
		synchronized(this){
		    lastOpenTile++;
		}
	}
	
	private void addWord(){
		//update the board with the new word
	}
	
	private void undoAddWord(){
		//remove the last added word from the board
	}
}