Refactor: move window dimensions to a new Constants class

src/main/java/ChatClient.java

@@ -6,8 +6,6 @@ import java.io.*;
 import java.net.Socket;
 
 public class ChatClient extends JFrame implements KeyListener {
-    private static final int WINDOW_WIDTH  = 800;
-    private static final int WINDOW_HEIGHT = 600;
     private String address;
     private int port;
     private Socket connectionToServer;
@@ -44,7 +42,7 @@ public class ChatClient extends JFrame implements KeyListener {
         add(inputTextField, BorderLayout.SOUTH);
 
         setVisible(true);
-        setSize(WINDOW_WIDTH, WINDOW_HEIGHT);
+        setSize(Constants.WINDOW_WIDTH, Constants.WINDOW_HEIGHT);
         setDefaultCloseOperation(EXIT_ON_CLOSE);
         setLocationRelativeTo(null);
     }

src/main/java/Constants.java

@@ -0,0 +1,4 @@
+public class Constants {
+    public static final int WINDOW_WIDTH  = 800;
+    public static final int WINDOW_HEIGHT = 600;
+}