added notification feature to commants

CheckersClient/core/src/com/mygdx/game/controllers/commands/cLobbyLeave.java

@@ -12,12 +12,22 @@ public class cLobbyLeave extends Command{
 
     @Override
     public void execute(PlayerController playerController, Connection connection){
-        if(data instanceof Integer){
-            int result = (int) data;
-            if (result == -1) System.out.println("Failed to leave lobby");
-            else {
-                playerController.setLobby(new Lobby(-1));
-                System.out.println("Request to leave lobby successful");
+        if(data instanceof Lobby){
+            Lobby lobby = (Lobby) data;
+            if(lobby.getID() != -1){
+                if (lobby.getPlayersID().contains((Integer) connection.getID())) {
+                    //Somebody else left
+                    System.out.println("Somebody left the lobby");
+                    playerController.setLobby(lobby);
+                }
+                else{
+                    //The current player left
+                    playerController.setLobby(new Lobby(-1));
+                    System.out.println("Request to leave lobby successful");
+                }
+            }
+            else{
+                System.out.println("Received leaveLobby command with an error");
             }
         }
     }