java-design-patterns/composite/src/main/java/com/iluwatar/LetterComposite.java

package com.iluwatar;

import java.util.ArrayList;
import java.util.List;

/**
 * 
 * Composite interface.
 *
 */
public abstract class LetterComposite {

	private List<LetterComposite> children = new ArrayList<LetterComposite>();

	public void add(LetterComposite letter) {
		children.add(letter);
	}
	
	public int count() {
		return children.size();
	}
	
	protected abstract void printThisBefore();

	protected abstract void printThisAfter();
	
	public void print() {
		printThisBefore();
		for (LetterComposite letter: children) {
			letter.print();
		}
		printThisAfter();
	}
}