Add flagging logic to cell

src/main/java/Minesweeper/Cell.java

@@ -28,6 +28,7 @@ public class Cell extends JButton {
 		cord = _cord;
 		playfield = _playfield;
 		
+		setBackground(Color.white);
 		addActionListener(new ActionListener() {
 			@Override
 			public void actionPerformed(ActionEvent e) {
@@ -48,18 +49,30 @@ public class Cell extends JButton {
 	}
 
 	protected void OnMouseClick() {
-		if (type != CellType.Bomb) {
-			flood();
-		} else {
-			playfield.reset();
+		if (!flagged) {
+			if (type != CellType.Bomb) {
+				flood();
+			} else {
+				playfield.reset();
+			}
 		}
 	}
 
 	protected void OnMouseRightClick() {
-		if (flagged) {
-			flagged = false;
-		} else {
-			flagged = true;
+		if (isEnabled()) {
+			if (flagged) {
+				flagged = false;
+
+				if (type == CellType.Number) {
+					setBackground(Color.gray);
+				} else {
+					setBackground(Color.red);
+				}
+
+			} else {
+				flagged = true;
+				setBackground(Color.cyan);
+			}
 		}
 	}
 
@@ -75,9 +88,11 @@ public class Cell extends JButton {
 		if (type == CellType.Bomb) {
 			return;
 		}
+		
 		setBackground(Color.LIGHT_GRAY);
 		setEnabled(false);
 		playfield.cellFlooded();
+		
 		if (value == 0) {
 			if (cord.y > 0) {
 				if (playfield.cells[cord.y - 1][cord.x].type == CellType.Number