package NET.worlds.scape;

import java.io.IOException;

public class DiffRoomSensor extends Sensor implements FrameHandler {
   private Room lastCamRoom;
   private static Object classCookie = new Object();

   @Override
   public void detach() {
      this.lastCamRoom = null;
      super.detach();
   }

   @Override
   public boolean handle(FrameEvent e) {
      Object owner = this.getOwner();
      if (owner != null && owner instanceof WObject) {
         WObject o = (WObject)owner;
         Room thisRoom = o.getRoom();
         Room thisCamRoom = Pilot.getActiveRoom();
         if (thisCamRoom != thisRoom && this.lastCamRoom == thisRoom) {
            this.trigger(e);
         }

         this.lastCamRoom = thisCamRoom;
         return true;
      } else {
         return true;
      }
   }

   @Override
   public void saveState(Saver s) throws IOException {
      s.saveVersion(0, classCookie);
      super.saveState(s);
   }

   @Override
   public void restoreState(Restorer r) throws IOException, TooNewException {
      switch (r.restoreVersion(classCookie)) {
         case 0:
            super.restoreState(r);
            return;
         default:
            throw new TooNewException();
      }
   }
}