/**
* update is an overwritten method of Observer, used in reaction to a change happening in an
* observed class. In this case it updates the instance variable HashMap itemMap, removing
* references to the Item at the old location, and adding it's reference to the new location. It
* also updates the locations that the Player has visited, adding the most recent Location first
* in the linked list. Note: more objects than Items and Player could be added later
*
* @param o : an Observable object (which should be an GameObject object of some sort)
* @param arg : an Object (which should be a Location object)
*/
public void update(Observable o, Object arg) {
/** Item update code* */
if (o instanceof Item && arg instanceof Integer) {
Item item = (Item) o;
int oldLocation = (Integer) arg;
int newLocation = item.getObjectLocation();
// remove old item from array list
ArrayList<Item> newList = itemMap.get((Integer) oldLocation);
if (newList != null) {
// For loop while there is another element
for (Iterator<Item> it = newList.iterator(); it.hasNext(); ) {
if (item.getObjectID() == it.next().getObjectID()) {
it.remove();
}
// End if matching id
}
// End for loop
// Update the item map with the new status with the item removed
itemMap.put((Integer) oldLocation, newList);
}
// if list not null
// If not 'destroyed', which is sent to location 9999
if (!(newLocation == 9999)) {
// add the item to the new location's array list
if (!(itemMap.containsKey((Integer) newLocation))) {
newList = new ArrayList<Item>();
newList.add(item);
itemMap.put((Integer) newLocation, newList);
} else {
newList = itemMap.get((Integer) newLocation);
// not checking for duplicates yet, add the item to the list
newList.add(item);
// Update the item map with the new status
itemMap.put((Integer) newLocation, newList);
}
// End contains key
}
// End if not destroyed
}
// End if valid instances of Item and Integer
/** Player update code* */
if (o instanceof Player && arg instanceof Integer) {
Player player = (Player) o;
int location = player.getObjectLocation();
// Add new locations the player visits Last in the linked list,
// which makes last element always the current
playerList.addLast(location);
}
// End if valid instances of Player and Integer
}
