The circle is not display

Question

Dear all
Why the circle not display on the panel?
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class CustomPanel1 extends JFrame { 
private final String list[] = { "Circle"};
private FlowLayout layout1, layout3;
private DrawShape drawPanel;
private JComboBox shapeList;
private JTextField textField1, textField2;
public static int size;
public CustomPanel1() {   
// create custom drawing area
drawPanel = new DrawShape();
shapeList = new JComboBox(list);
shapeList.setMaximumRowCount(3);
//add ItemListener
shapeList.addItemListener(
new ItemListener(){
// handle item state change event
public void itemStateChanged (ItemEvent event) {                  
if(event.getStateChange() == ItemEvent.SELECTED){
// draw circle
if( shapeList.getSelectedIndex() == 0){           
DrawShape.shape = 0;
drawPanel.draw( DrawShape.Circle);
} // end if
JPanel parameterPanel = new JPanel();
layout1 = new FlowLayout();
parameterPanel.setLayout(layout1);
parameterPanel.setBackground( Color.PINK );
layout1.setAlignment( FlowLayout.CENTER);
parameterPanel.add( new JScrollPane(shapeList));
JPanel textPanel = new JPanel();
layout3 = new FlowLayout();
parameterPanel.setLayout(layout3);
textPanel.setBackground( Color.PINK );
layout3.setAlignment( FlowLayout.CENTER);
textField1 = new JTextField( "Size");
textField1.setFont(new Font("Serif",Font.BOLD,14));
textField1.setEditable (false);
textField2 = new JTextField( "",6);
textField2.setFont(new Font("Serif",Font.BOLD,14));
// add ActionListener
textField2.addActionListener(
new ActionListener(){
// handle action perform event
public void actionPerformed (ActionEvent event) {         
JTextField field = (JTextField)event.getSource();
String entry = field.getText();
size = Integer.parseInt(entry);
} // end handle
} // end anonymous inner class
); // end call to addActionListener
textPanel.add(textField1, BorderLayout.NORTH);
textPanel.add(textField2, BorderLayout.SOUTH);
// set up the combine panel of parameterPanel and textPanel
GridLayout gridLayout = new GridLayout();
gridLayout.setRows(2);
gridLayout.setColumns(1);
JPanel combinPanel = new JPanel();
combinPanel.setBackground( Color.PINK );
combinPanel.setLayout(gridLayout);
combinPanel.add(parameterPanel, BorderLayout.NORTH);
combinPanel.add(textPanel, BorderLayout.SOUTH);
Container container = getContentPane();
container.add( combinPanel, BorderLayout.NORTH);
container.add( drawPanel, BorderLayout.CENTER );
// container.add( dataPanel, BorderLayout.SOUTH );
setSize( 500, 500 );
setVisible( true );
} // end constructor CustomPanelTest
// main
public static void main ( String args[] ) {   
CustomPanel1 app = new CustomPanel1();
app.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
} // end main
} // end class CustomPanelTest
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class DrawShape extends JPanel {
public final static int Circle = 0, Square = 1, Triangle = 2;
public static int shape;
public static int xPos,yPos;
CustomPanel1 client;
boolean shapeWasCreated = false;
public DrawShape(){
public DrawShape(CustomPanel1 customer){     
this.client = customer;
addMouseListener(
new MouseAdapter() {  // anonymous inner class
// handle mouse press event
public void mousePressed( MouseEvent event )
xPos = event.getX();
yPos = event.getY();
shapeWasCreated = true;
repaint();
} // end handle
} // end anonymous inner class
); // end call to addMouseListener
} // end method
public void draw( int shapeToDraw )
shape = shapeToDraw;
repaint();
} //end method
} // end class
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class DrawCircle extends DrawShape {
CustomPanel1 client;
public static double circleArea, circlePerimeter;
public DrawCircle(CustomPanel1 circleCustomer){     
super(circleCustomer);
this.client = circleCustomer;
} // end method
public void paintComponent( Graphics g )
super.paintComponent( g );
initializeShapeVariables();
if ( shape == Circle ) {        
g.drawOval(xPos ,yPos , CustomPanel1.size, CustomPanel1.size );
} //end if
private void initializeShapeVariables(){
area = 0;
perimeter = 0;
circleArea = 0;
circlePerimeter = 0;
} // end method
// set shape value and repaint
public void draw( int shapeToDraw ) {    
shape = shapeToDraw;
repaint();
} //end method
} // end class

Answer 1

First, try a system reset.  It cures many ills and it's quick, easy and harmless...
Hold down the on/off switch and the Home button simultaneously until you see the Apple logo.  Ignore the "Slide to power off" text if it appears.  You will not lose any apps, data, music, movies, settings, etc.
If the Reset doesn't work, try a Restore.  Note that it's nowhere near as quick as a Reset.  It could take well over an hour!  Connect via cable to the computer that you use for sync.  From iTunes, select the iPad/iPod and then select the Summary tab.  Follow directions for Restore and be sure to say "yes" to the backup.  You will be warned that all data (apps, music, movies, etc.) will be erased but, as the Restore finishes, you will be asked if you wish the contents of the backup to be copied to the iPad/iPod.  Again, say "yes."
At the end of the basic Restore, you will be asked if you wish to sync the iPad/iPod.  As before, say "yes."  Note that that sync selection will disappear and the Restore will end if you do not respond within a reasonable time.  If that happens, only the apps that are part of the IOS will appear on your device.  Corrective action is simple -  choose manual "Sync" from the bottom right of iTunes.
If you're unable to do the Restore, go into Recovery Mode per the instructions here.  Since you have chosen not to maintain a backup, Recovery Mode will result in complete loss of data.  Anything obtained from the iTunes Store can be downloaded again but everything else will be gone forever.