package cz.cuni.amis.pogamut.defcon.utils;
   
   import java.util.LinkedList;
   
   /**
    * Simple flag monitoring changes in a value.
    * 
    * @author Radek 'Black_Hand' Pibil
    * 
   * @param <T>
   */
  public class SimpleFlag<T> {
  	private LinkedList<AdvancedFlagListener<T>> listeners = new LinkedList<AdvancedFlagListener<T>>();
  	
  	private T value;
  
  	public void addStrongListener(AdvancedFlagListener<T> listener) {
  		listeners.addLast(listener);
  	}
  
  	public void clearListeners() {
  		listeners.clear();
  	}
  
  	public T getFlag() {
  		return value;
  	}
  
  	public void removeListener(AdvancedFlagListener<T> listener) {
  		listeners.remove(listener);
  	}
  
  	public void setFlag(T newValue) {
  		if (newValue == value)
  			return;
  		
  		T oldValue = value;
  		value = newValue;
  		
  		for (AdvancedFlagListener<T> listener : listeners) {
  			listener.flagChanged(oldValue, newValue);
  		}
  	}
  	
  	public SimpleFlag(T value) {
  		this.value = value;
  	}
  }