Moved playfield logic to new class

src/main/java/Minesweeper/MinesweeperGame.java

@@ -7,54 +7,14 @@ import javax.swing.JPanel;
 public class MinesweeperGame extends JPanel {
 
 	private static final long serialVersionUID = 1L;
-	private static final int WIDTH = 600, HEIGTH = 600;
-	private static final int CELLSIZE = 40;
-	private int playfieldSize;
-	private int bombAmount;
+	public static final int WIDTH = 600, HEIGTH = 600;
 
-	public Cell[][] playfield;
+	public Playfield playfield;
 
 	public MinesweeperGame(int _playfieldSize, int _bombAmount) {
 		this.setSize(WIDTH, HEIGTH);
-		playfieldSize = _playfieldSize;
-		bombAmount = _bombAmount;
 		setLayout(null);
-
-		initPlayfield();
-	}
-
-	private void initPlayfield() {
-
-		playfield = new Cell[playfieldSize][playfieldSize];
-
-		int[] bPlacment = new int[bombAmount];
-		for (int i = 0; i < bPlacment.length; i++) {
-			bPlacment[i] = (int) (Math.random() * playfieldSize * playfieldSize);
-
-			for (int j = 0; j < i; j++) {
-				if (bPlacment[i] == bPlacment[j]) {
-					i--;
-					break;
-				}
-			}
-		}
-
-		for (int i = 0; i < playfieldSize; i++) {
-			for (int j = 0; j < playfieldSize; j++) {
-				playfield[i][j] = new Cell(CellType.Number);
-				
-				playfield[i][j].setBounds(j * CELLSIZE + (WIDTH / 2 - playfieldSize * CELLSIZE / 2),
-						i * CELLSIZE + (HEIGTH / 2 - playfieldSize * CELLSIZE / 2), CELLSIZE, CELLSIZE);
-				add(playfield[i][j]);
-				
-				for (int k = 0; k < bPlacment.length; k++) {
-					if (bPlacment[k] == i * playfieldSize + j) {
-						playfield[i][j].type = CellType.Bomb;
-						break;
-					}
-				}
-			}
-		}
+		playfield = new Playfield(this, _playfieldSize, _bombAmount );
 	}
 
 	public static void main(String[] args) {

src/main/java/Minesweeper/Playfield.java

@@ -0,0 +1,46 @@
+package Minesweeper;
+
+public class Playfield {
+
+	private static final int CELLSIZE = 40;
+	private int playfieldSize;
+	private MinesweeperGame MsG;
+	public Cell[][] playfield;
+
+	public Playfield(MinesweeperGame _MsG, int _playfieldSize, int _bombAmount) {
+		MsG = _MsG;
+		playfieldSize = _playfieldSize;
+		
+		playfield = new Cell[playfieldSize][playfieldSize];
+
+		int[] bPlacement = new int[_bombAmount];
+		for (int i = 0; i < bPlacement.length; i++) {
+			bPlacement[i] = (int) (Math.random() * playfieldSize * playfieldSize);
+
+			for (int j = 0; j < i; j++) {
+				if (bPlacement[i] == bPlacement[j]) {
+					i--;
+					break;
+				}
+			}
+		}
+
+		for (int i = 0; i < playfieldSize; i++) {
+			for (int j = 0; j < playfieldSize; j++) {
+				playfield[i][j] = new Cell(CellType.Number);
+
+				playfield[i][j].setBounds(j * CELLSIZE + (MsG.WIDTH / 2 - playfieldSize * CELLSIZE / 2),
+						i * CELLSIZE + (MsG.HEIGTH / 2 - playfieldSize * CELLSIZE / 2), CELLSIZE, CELLSIZE);
+				MsG.add(playfield[i][j]);
+
+				for (int k = 0; k < bPlacement.length; k++) {
+					if (bPlacement[k] == i * playfieldSize + j) {
+						playfield[i][j].type = CellType.Bomb;
+						break;
+					}
+				}
+			}
+		}
+	}
+
+}

src/test/java/Minesweeper/MinesweeperGameTest.java

@@ -17,7 +17,7 @@ class MinesweeperGameTest {
 		
 		int bombCounter = 0;
 		
-		for(Cell[] row : m.playfield){
+		for(Cell[] row : m.playfield.playfield){
 			for (Cell c : row) {
 				if(c.type == CellType.Bomb) {
 					bombCounter++;