What's wrong on the superclass and subclass

Question

Dear all,
The drawing panel cannot draw the figures, what's wrong?
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.util.*;
public class CustomPanel1 extends JFrame { 
private final String list[] = { "Circle", "Square", "Triangle"};
private FlowLayout layout1, layout2, layout3;
private DrawShape drawPanel;
private JButton clearButton;
public static JLabel label;
private JComboBox shapeList;
private JTextField textField1, textField2;
public static int size;
// set up GUI
public CustomPanel1() {   
// create custom drawing area
drawPanel = new DrawShape(this);
// set up ClearButton
clearButton = new JButton( "Clear" );
// add the ActionListeber
clearButton.addActionListener(
new ActionListener() { // anonymous inner class
// handle action perform event
public void actionPerformed( ActionEvent event ) {        
// clear originList
drawPanel.originList.clear();
drawPanel.area = 0;
drawPanel.perimeter = 0;
label.setText("Area " + drawPanel.area +
" Perimeter " + drawPanel.perimeter );
repaint();
}// end handle
} // end anonymous inner class
); // end call to addActionListener
//set up combox
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){           
DrawCircle.shape = 0;
DrawCircle.draw(DrawCircle.Circle);
} // end if
// draw square
else if ( shapeList.getSelectedIndex() == 1) {           
DrawShape.shape = 1;
DrawSquare.draw( DrawSquare.Square);
} // end if
// draw triangle
else if ( shapeList.getSelectedIndex() == 2) {           
DrawShape.shape = 2;
DrawTriangle.draw( DrawTriangle.Triangle);
} // end if
} // end if
} // end handle
} // end anonymous inner class
); // end call to addActionListener
// set up parameter panel containing parameter
JPanel parameterPanel = new JPanel();
layout1 = new FlowLayout();
parameterPanel.setLayout(layout1);
parameterPanel.setBackground( Color.PINK );
layout1.setAlignment( FlowLayout.CENTER);
parameterPanel.add( new JScrollPane(shapeList));
parameterPanel.add( clearButton );
// set up the text Panel and textfield
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);
// set up datapanel conaining data
JPanel dataPanel = new JPanel();
layout2 = new FlowLayout();
dataPanel.setLayout(layout2);
dataPanel.setBackground( Color.PINK );
label = new JLabel ("Area " + drawPanel.area + "Perimeter " +
drawPanel.perimeter, SwingConstants.CENTER);
dataPanel.add( label);
// attach button panel & custom drawing area to content pane
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
// A customized JPanel class.
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.util.*;
class DrawShape extends JPanel {
public final static int Circle = 0, Square = 1, Triangle = 2;
public static int shape;
public int xPos,yPos;
java.util.List originList;
public int count = 0;
public static double area ;
public static double perimeter ;
final double pi=3.141592;
CustomPanel1 client;
boolean shapeWasCreated = false;
public DrawShape(CustomPanel1 customer){     
this.client = customer;
// set up the list of shape to draw
originList = new ArrayList();
// set up mouse listener
addMouseListener(
new MouseAdapter() {  // anonymous inner class
// handle mouse press event
public void mousePressed( MouseEvent event )
xPos = event.getX();
yPos = event.getY();
originList.add(count, new String(
shape + "." + xPos + "," + yPos + "*" + CustomPanel1.size ));
// set to draw ready
shapeWasCreated = true;
repaint();
} // end handle
} // end anonymous inner class
); // end call to addMouseListener
} // end method
} // end class
// A customized JPanel class.
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.util.*;
public class DrawCircle extends DrawShape {
public static double circleArea, circlePerimeter;
public DrawCircle(CustomPanel1 customer){
super(customer);
} // end method
// use shape to draw an oval, rectangle or triangle
public void paintComponent( Graphics g )
super.paintComponent( g );
initializeShapeVariables();
for(int i = 0; i<originList.size(); i++){
String XY =(String)originList.get(i);
int star = XY.indexOf("*");
int dot = XY.indexOf(".");
int comma = XY.indexOf(",");
int shapeToDraw = Integer.parseInt(XY.substring(0,dot));
int pickedX = Integer.parseInt(XY.substring(dot + 1,comma));
int pickedY = Integer.parseInt(XY.substring(comma + 1, star));
int shapeSize = Integer.parseInt(XY.substring(star + 1));
int x = pickedX-(shapeSize/2);
int y = pickedY-(shapeSize/2);
// draw a circle
if ( shapeToDraw == Circle ) {        
g.drawOval(x ,y , shapeSize, shapeSize );
if(shapeWasCreated){
circleArea = (pi * (((double)(shapeSize)/2) * (((double)shapeSize)/2)));
area += circleArea;
circlePerimeter = (pi * (shapeSize));
perimeter += circlePerimeter;
CustomPanel1.label.setText("Area " + area + "Perimeter " + perimeter);
} //end if
} //end if
} // end for
if(shapeWasCreated)
shapeWasCreated = false;
} // end if
private void initializeShapeVariables(){
area = 0;
perimeter = 0;
circleArea = 0;
circlePerimeter = 0;
} // end method
// set shape value and repaint
public static void draw( int shapeToDraw )
shape = shapeToDraw;
//repaint();
} //end method
} // end class
// A customized JPanel class.
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.util.*;
public class DrawSquare extends DrawShape {
public static double squareArea, squarePerimeter;
public DrawSquare(CustomPanel1 customer){
super(customer);
} // end method
// use shape to draw an oval, rectangle or triangle
public void paintComponent( Graphics g )
super.paintComponent( g );
initializeShapeVariables();
for(int i = 0; i<originList.size(); i++){
String XY =(String)originList.get(i);
int star = XY.indexOf("*");
int dot = XY.indexOf(".");
int comma = XY.indexOf(",");
int shapeToDraw = Integer.parseInt(XY.substring(0,dot));
int pickedX = Integer.parseInt(XY.substring(dot + 1,comma));
int pickedY = Integer.parseInt(XY.substring(comma + 1, star));
int shapeSize = Integer.parseInt(XY.substring(star + 1));
int x = pickedX-(shapeSize/2);
int y = pickedY-(shapeSize/2);
if ( shapeToDraw == Square ){        
g.drawRect( x, y, shapeSize, shapeSize );
if(shapeWasCreated){
squareArea = ( shapeSize * shapeSize);
area += squareArea;
squarePerimeter = (4 * shapeSize);
perimeter += squarePerimeter;
CustomPanel1.label.setText("Area " + area + "Perimeter " + perimeter);
} //end if
} //end if
} // end for
if(shapeWasCreated)
shapeWasCreated = false;
} // end if
private void initializeShapeVariables(){
area = 0;
perimeter = 0;
squareArea = 0;
squarePerimeter = 0;
} // end method
// set shape value and repaint
public static void draw( int shapeToDraw )
shape = shapeToDraw;
//repaint();
} //end method
} // end class
// A customized JPanel class.
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.util.*;
public class DrawTriangle extends DrawShape {
public static double triangleArea, trianglePerimeter;
public DrawTriangle(CustomPanel1 customer){
super(customer);
} // end method
// use shape to draw an oval, rectangle or triangle
public void paintComponent( Graphics g )
super.paintComponent( g );
initializeShapeVariables();
for(int i = 0; i<originList.size(); i++){
String XY =(String)originList.get(i);
int star = XY.indexOf("*");
int dot = XY.indexOf(".");
int comma = XY.indexOf(",");
int shapeToDraw = Integer.parseInt(XY.substring(0,dot));
int pickedX = Integer.parseInt(XY.substring(dot + 1,comma));
int pickedY = Integer.parseInt(XY.substring(comma + 1, star));
int shapeSize = Integer.parseInt(XY.substring(star + 1));
int x1=pickedX-(shapeSize/2);
int y1=pickedY+(shapeSize/2);
int x2=pickedX+(shapeSize/2);
int y2=y1;
int x3=pickedX;
int y3=pickedY-((int)(1.73205*shapeSize*0.33333));
if (shapeToDraw == Triangle)
g.drawLine(x1, y1, x2, y2);
g.drawLine(x1, y1, x3, y3);
g.drawLine(x3, y3, x2, y2);
if(shapeWasCreated){
triangleArea = (double)(shapeSize * shapeSize/2);
area += triangleArea;
trianglePerimeter = (3 * (shapeSize));
perimeter += trianglePerimeter;
CustomPanel1.label.setText("Area " + area + "Perimeter " + perimeter);
} //end if
} //end if
} // end for
if(shapeWasCreated)
shapeWasCreated = false;
} // end if
private void initializeShapeVariables(){
area = 0;
perimeter = 0;
triangleArea = 0;
trianglePerimeter = 0;
} // end method
// set shape value and repaint
public static void draw( int shapeToDraw )
shape = shapeToDraw;
//repaint();
} //end method
} // end class

Answer 1

The drawing panel cannot draw the figures, what's
wrong?You can't have written this much code and then suddenly detected it doesn't work at all. You must now restart from the point where you had a working program. Then you add code is small increments and see to it that it works in each step and you understand why it works. This method is called stepwise refinement and it does wonders.