StateHandler.java

package de.bitbrain.guice;

import java.util.HashMap;
import java.util.Map;

import com.google.inject.Inject;
import com.google.inject.Injector;
import com.google.inject.name.Named;

public class StateHandler {
  
  private Map<Integer, State> states;
  
  private State current;
  
  @Inject @Named("stateScope") StateScope scope;
  
  @Inject
  private Injector injector;
  
  public StateHandler() {
    states = new HashMap<Integer, State>();
    current  = null;
  }
  
  public void register(int id, Class<? extends State> stateClass) {
    scope.enter(stateClass);
    states.put(id, injector.getInstance(stateClass));
  }
  
  public void setState(Class<? extends State> stateClass) {
    scope.leave();
    scope.enter(stateClass);
    current = injector.getInstance(stateClass);
    current.enter();
  }

  void setState(int id) {
    
    if (current != null) {
      scope.leave();
      current.leave();
    }
    
    current = states.get(id);
    
    if (current != null)
      current.enter();
  }
  
  public void run() {
    if (current != null) {
      current.run();
    }
  }
}