Add Cell to Minesweeper, replacing JButtons / Move playfield to center

src/main/java/Minesweeper/Cell.java

@@ -1,7 +1,11 @@
 package Minesweeper;
 
+import javax.swing.JButton;
+
 enum CellType{Number, Bomb}
-public class Cell {
+public class Cell extends JButton {
+	
+	private static final long serialVersionUID = 1L;
 	public CellType type;
 	public boolean flagged = false;
 	public int value = -1;
@@ -9,7 +13,4 @@ public class Cell {
 	public Cell(CellType _type) {
 		type = _type;
 	}
-	
-	
-	
 }

src/main/java/Minesweeper/MinesweeperGame.java

@@ -11,20 +11,26 @@ public class MinesweeperGame extends JPanel {
 	private static final int CELLSIZE = 40;
 	private int playfieldSize;
 
+	public Cell[][] playfield;
+
 	public MinesweeperGame(int _playfieldSize) {
 		this.setSize(WIDTH, HEIGTH);
 		playfieldSize = _playfieldSize;
 		setLayout(null);
-		
+
 		initPlayfield();
 	}
 
 	private void initPlayfield() {
+
+		playfield = new Cell[playfieldSize][playfieldSize];
+
 		for (int i = 0; i < playfieldSize; i++) {
 			for (int j = 0; j < playfieldSize; j++) {
-				JButton b = new JButton();
-				b.setBounds(j * CELLSIZE, i * CELLSIZE, CELLSIZE, CELLSIZE);
-				add(b);
+				Cell c = new Cell(CellType.Number);
+				c.setBounds(j * CELLSIZE + (WIDTH / 2 - playfieldSize * CELLSIZE / 2), i * CELLSIZE + (HEIGTH / 2 - playfieldSize * CELLSIZE / 2), CELLSIZE,
+						CELLSIZE);
+				add(c);
 			}
 		}
 	}