Here is where i got a problem: When i want ot fire button Marchewkaim getting error null pointer exception:
public class MainFrame extends JFrame {
public static void Draw()
{
mp.repaint();
}
private static final long serialVersionUID = 1L;
private JPanel jContentPane = null;
static private MyPanel mp = null;
/**
* This method initializes mp
*
* @return MyPanel
*/
private MyPanel getMp() {
if (mp == null) {
mp = new MyPanel();
mp.setLayout(null);
}
return mp;
}
/**
* @param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub
SwingUtilities.invokeLater(new Runnable() {
public void run() {
MainFrame thisClass = new MainFrame();
thisClass.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
thisClass.setVisible(true);
}
});
}
/**
* This is the default constructor
*/
public MainFrame() {
super();
initialize();
}
/**
* This method initializes this
*
* @return void
*/
private JPanel getJContentPane() {
if (jContentPane == null) {
jContentPane = new JPanel();
jContentPane.setLayout(new CardLayout(0, 0));
}
return jContentPane;
}
private void initialize() {
this.setSize(668, 402);
this.setContentPane(getJContentPane());
this.setTitle("JFrame");
JPanel panel = new JPanel();
panel.setLayout(null);
this.getContentPane().add(panel, "Main");
panel.setVisible(true);
JButton btnMarchewka = new JButton("Marchewka");
btnMarchewka.setBounds(12, 25, 113, 49);
panel.add(btnMarchewka);
JButton btnArbuz = new JButton("Arbuz");
btnArbuz.setBounds(12, 87, 113, 49);
panel.add(btnArbuz);
JButton btnUsun = new JButton("Usun ostatni");
btnUsun.setBounds(12, 149, 113, 49);
panel.add(btnUsun);
btnMarchewka.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e)
{
Draw();
}
});
}
/**
* This method initializes jContentPane
*
* @return javax.swing.JPanel
*/
} // @jve:decl-index=0:visual-constraint="10,10"
Another class
public class MyPanel extends JPanel {
public GObject c;
public GObject w;
// @jve:decl-index=0:
private static final long serialVersionUID = 1L;
public List<GObject> list= new ArrayList<GObject>();
/**
* This is the default constructor
*/
public MyPanel() {
super();
initialize();
}
public void addCarrot()
{
GObject[] c=new GObject[list.size()+1];
c[list.size()]=new Carrot();
list.add(c[list.size()]);
MainFrame.Draw();
}
public void addWatermelon()
{
GObject[] w=new Watermelon[list.size()+1];
w[list.size()]=new Watermelon();
list.add(w[list.size()]);
MainFrame.Draw();
}
public void remove()
{
list.remove(list.size()-1);
MainFrame.Draw();
}
/**
* This method initializes this
*
* @return void
*/
private void initialize() {
this.setSize(400, 400);
this.setLayout(null);
}
@Override
protected void paintComponent(Graphics arg0) {
// TODO Auto-generated method stub
super.paintComponent(arg0);
if
(list!=null){
for(int i=0;i<list.size();i++)
{
list.get(i).drawMe(arg0);
}
}
}
}
I tried to resolve this error on my own but i cant find where im pointing at nothing. Doing this for 6 hrs and im sick and tired.Im looking for some tips .
