membuat tombol priview

//action tombolnya
private void titikActionPerformed(java.awt.event.ActionEvent evt) {
layar = new titik();
layar.repaint();
layer.setViewportView(layar);
layar.setAutoscrolls(true);
}

//class titiknya
class titik extends JPanel{
public void paintComponent(Graphics titik1) {
super.paintComponent(titik1);
titik1.setColor(Color.BLACK);
titik1.drawLine(90, 90, 90, 90);
}
}