Trying to move a graphics object using buttons.

Question

Hello, im fairly new to GUI's. Anyway I have 1 class which makes my main JFrame, then I have another 2 classes, one to draw a lil square graphics component (which iwanna move around) which is placed in the center of my main frame and then another class to draw a Buttonpanel with my buttons on which is placed at the bottom of my main frame.
I have then made an event handling class which implements ActionListner, I am confused at how I can get the graphics object moving, and where I need to place the updateGUI() method which the actionPerformed method calls from inside the event handling class.
I am aware you can repaint() graphics and assume this would be used, does anyone have a good example of something simular being done or could post any help or code to aid me, thanks!

Answer 1

Yeah.. here's an example of custom painting on a JPanel with a box. I used a mouse as it was easier for me to setup than a nice button panel on the side.
Anyways... it should make it pretty clear how to get everything setup, just add a button panel on the side. and use it to move the box instead of the mouse.
-Js
import java.awt.Color;
import java.awt.Graphics;
import java.awt.event.MouseEvent;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.event.MouseInputAdapter;
public class MoveBoxAroundExample extends JFrame
     private final static int SQUARE_EDGE_LENGTH = 40;
     private JPanel panel;
     private int xPos;
     private int yPos;
     public MoveBoxAroundExample()
          this.setSize(500,500);
          this.setDefaultCloseOperation(javax.swing.JFrame.EXIT_ON_CLOSE);
          this.setContentPane(getPanel());
          xPos = 250;
          yPos = 250;
          this.setVisible(true);     
     private JPanel getPanel()
          if(panel == null)
               panel = new JPanel()
                    public void paintComponent(Graphics g)
                         super.paintComponent(g);
                         g.setColor(Color.RED);
                         g.fillRect(xPos-(SQUARE_EDGE_LENGTH/2), yPos-(SQUARE_EDGE_LENGTH/2), SQUARE_EDGE_LENGTH, SQUARE_EDGE_LENGTH);
               MouseInputAdapter mia = new MouseInputAdapter()
                    public void mousePressed(MouseEvent e)
                        xPos = e.getX();
                        yPos = e.getY();
                        panel.repaint();
                    public void mouseDragged(MouseEvent e)
                        xPos = e.getX();
                        yPos = e.getY();
                        panel.repaint();
               panel.addMouseListener(mia);
               panel.addMouseMotionListener(mia);
          return panel;
     public static void main(String args[])
          new MoveBoxAroundExample();
}