EvilHangman Facade Example

EvilHangman.java

//Assume that all necessary packages are imported

public class EvilHangman implements HangmanInterface {
    //Assume all private member variables including dictionary and letters guessed,
    //num guesses, etc have been instantiated
    
    private int guessesRemaining,wordLength;
    
    //Now here's the important piece: we're going to have the EvilHangman game
    //maintain a private, REGULAR hangman game.
    
    private MyHangmanGame realHangman;
    
    public EvilHamgnan(int length,int numGuess){
        //Assume all of the private member variables have been set
        guessesRemaining = numGuess;
        wordLength = wordLength;
        
        realHangman = null;
    }
    
    //So now let's take a look at the most important method - makeGuess
    
    public void makeGuess(char guessed){
        //Don't worry about this if statement right now. I explain it lower on the page.
        if(realHangman != null) realHangman.makeGuess(guessed);
        
        //Do all of the other dictionary processing, etc. We don't need to see that here
        
        //I'm just throwing a dummy method in here -
        //assume this method returns true if the committing condition has been reached
        //(that is, if the dictionary cannot be "pruned" any farther, or no more words can
        //be removed without deleting the entire dictionary)
        if(mustCommitToAWord()){
            String secretWord = getSecretWord(); // <-- Randomly picks a word from the dictionary
            
            //Now here's the facade part: when the game has to commit, it instantiates a REGULAR
            //hangman game. This game will play regular, non-evil hangman until one of the end
            //conditions is reached (win or loss).
            
            //We construct the MyHangmanGame with the secret word we randomly picked, as well as
            //pass along the number of guesses left. This means that the game seamlessly switches
            //into the normal hangman game instance, and passes all of the information over.
            
            realHangman = new MyHangmanGame(secretWord,guessesRemaining);
            
        }
    }
    
    public boolean isWin(){
        //Here's the magic: we set realHangman to null in the constructor.
        //This provides us a really easy way to see whether or not we are playing
        //real hangman. At the beginning of every other hangman game method, we check to
        //see if the real hangman game has been instantiated. If it has been, we know
        //that the game has committed to a word and is playing regular hangman.
        //If this is happening, we pass along the information for the method call
        //to methods of realHangman. The trick here is that we know MyHangmanGame
        //and EvilHangman are both implementing the SAME HangmanGame interface. This means
        //that we can call all of the same methods without worrying about something breaking.
        
        if(realHangman != null) return realHangman.isWin();
        
        //Go through the actual logic of determining a win here.
        //I stubbed it out because it'd get too verbose to rewrite
        //that here.
        return (true or false);
    }
    
    
    //I provided a couple more examples of facade methods here. This
    //is how you would implement the facade concept on all of the other
    //methods in your EvilHangman class.
    
    public String getSecretWord(){
        if(realHangman != null) return realHangman.getSecretWord();
        
        return someString;
    }
    
    public int numGuessesRemaining(){
        if(realHangman != null) return realHangman.numGuessesRemaining();
        
        return guessesRemaining;
    }
    
}