refactoring: add PropertyChangeSupport

src/main/java/de/hsfulda/onses/models/Game.java

@@ -3,10 +3,16 @@ package de.hsfulda.onses.models;
 import de.hsfulda.onses.services.GameService;
 import de.hsfulda.onses.services.PlayerService;
 
+import java.beans.PropertyChangeSupport;
 import java.util.ArrayList;
 
 public class Game {
 
+    public final static String PROPERTY_LAST_PLAYED_CARD = "lastPlayedCard";
+    public final static String PROPERTY_DRAW_CARD_DECK = "drawCardDeck";
+
+    protected PropertyChangeSupport listeners;
+
     private GameService gameService;
     private PlayerService playerService;
 
@@ -22,7 +28,9 @@ public class Game {
         lastPlayedCard.setColor(color);
     }
     public Game setLastPlayedCard(Card lastPlayedCard) {
+        final Card oldLastPlayedCard = this.lastPlayedCard;
         this.lastPlayedCard = lastPlayedCard;
+        this.firePropertyChange(PROPERTY_LAST_PLAYED_CARD, oldLastPlayedCard, lastPlayedCard);
         return this;
     }
 
@@ -31,7 +39,9 @@ public class Game {
     }
 
     public void addCardToDrawCardDeck(Card card) {
+        final ArrayList<Card> oldCards = new ArrayList<>(this.drawCardDeck);
         drawCardDeck.add(card);
+        this.firePropertyChange(PROPERTY_DRAW_CARD_DECK, oldCards, drawCardDeck);
     }
 
     public GameService getGameService() {
@@ -56,4 +66,19 @@ public class Game {
     {
         this.playerService = new PlayerService().setGame(this);
     }
+
+    public PropertyChangeSupport listeners() {
+        if(this.listeners == null) {
+            this.listeners = new PropertyChangeSupport(this);
+        }
+        return this.listeners;
+    }
+
+    public boolean firePropertyChange(String propertyName, Object oldValue, Object newValue) {
+        if(this.listeners != null) {
+            this.listeners.firePropertyChange(propertyName, oldValue, newValue);
+            return true;
+        }
+        return false;
+    }
 }