Calculator 's functions. Difficult. need some help.

Question

I did do for my own calculator,but i got problem with animation and sound for the calculator. Like :
Pressing a wrong combination of keys may generate a warning sound. Moreover an animated icon
should be used to indicate when:
+ the calculator is idle and free to be used
+ the calculator is busy ( being used )
This is my own program, anybody can show me how to add the warning sound and animation icon according above requirement ???? Or any online tutorial about this one. This program is working on the right way, but i don't know how to add some more feature like animation icon, and warning sound.Pleaseeeeeeeeeeeee help me, it is urgent.
import java.awt.event.*;
import java.awt.*;
public class Calculator extends Frame implements ActionListener
TextField name;
Label aHeader;
Button b[];
String expression;
// Calculator Constructor
// This operator constructor ( as with all constructors ) is executed when the new object
// is created. In this case we create all the buttons ( and the panels that contain them )
// then reset the calculator
public Calculator()
super("DUY 'S CALCULATOR");     
setLayout(new BorderLayout());     
Panel p1 = new Panel();
p1.setBackground(new Color(18,70,1));
p1.setLayout(new FlowLayout());
aHeader = new Label("DUY'S CALCULATOR");
aHeader.setFont(new Font("Times New Roman",Font.BOLD,24));
aHeader.setForeground(new Color(255,0,0));
p1.add(aHeader);
// Question: what does 'North' mean here ?
// The applet places a GridLayout on the 'North' side
add("North",p1);
Panel p2 = new Panel();
p2.setBackground(new Color(27,183,100));
p2.setLayout(new GridLayout(0,1));
// When you create p2 GridLayout you specify 'new GridLayout(0,1) 'which means create a new GridLayout with 1 column .( no row)
name = new TextField(20); // Var for Text field max of 20 characters
p2.add(name);
add("Center",p2);
Panel p3 = new Panel();
p3.setLayout(new GridLayout(0,6));
// When you create p3 GridLayout you specify 'new GridLayout(0,1) 'which means create a new GridLayout with 6 columns .( no row)
b = new Button[25];
b[0] = new Button("MC");     // Create Button MC
b[0].addActionListener(this);
b[1] = new Button("7");     // Create Button Seven
b[1].addActionListener(this);
b[2] = new Button("8");     // Create Button Eight
b[2].addActionListener(this);
b[3] = new Button("9");     // Create Button Nine
b[3].addActionListener(this);
b[4] = new Button("/");     // Create Button Div
b[4].addActionListener(this);
b[5] = new Button("sqrt");     // Create Button SQRT
b[5].addActionListener(this);
b[6] = new Button("CE");     // Create Button CE
b[6].addActionListener(this);
b[7] = new Button("4");     // Create Button Four
b[7].addActionListener(this);
b[8] = new Button("5");     // Create Button Five     
b[8].addActionListener(this);
b[9] = new Button("6");     // Create Button Six
b[9].addActionListener(this);
b[10] = new Button("*");     // Create Button Multi
b[10].addActionListener(this);
b[11] = new Button("%");     // Create Button Percent
b[11].addActionListener(this);
b[12] = new Button("MS");     // Create Button MS
b[12].addActionListener(this);
b[13] = new Button("1");     // Create Button One
b[13].addActionListener(this);
b[14] = new Button("2");     // Create Button Two
b[14].addActionListener(this);
b[15] = new Button("3");     // Create Button Three
b[15].addActionListener(this);
b[16] = new Button("-");     // Create Button Minus
b[16].addActionListener(this);
b[17] = new Button("1/x");     // Create Button Calculates the multiplicative inverse
b[17].addActionListener(this);
b[18] = new Button("M+");     // Create Button M+
b[18].addActionListener(this);
b[19] = new Button("0");     // Create Button Zero     
b[19].addActionListener(this);
b[20] = new Button("+/-");     // Create Button +/-
b[20].addActionListener(this);
b[21] = new Button(".");     // Create Button point
b[21].addActionListener(this);
b[22] = new Button("+");     // Create Button Plus
b[22].addActionListener(this);
b[23] = new Button("=");     // Create Button Equal     
b[23].addActionListener(this);
b[24] =new Button("exit");     // Create Button Exit
b[24].addActionListener(this);
// clearAll sets the attributes of the Calculator object to initial values ( this is
// the operation that is called when the user click on the "CE" button.
for(int i=0;i<=24;i++)
{      p3.add(b[i]);
add("South",p3);
// Question : what does 'South' mean here ? The applet places a GridLayout on the
// 'South' side
super.addWindowListener(new WindowAdapter(){
public void windowClosing(WindowEvent e)
{System.exit(0);}});
// Window Closing
// This operation is called in response to a window closing event. It should simply
// exit the program
setLocation(200,100);
pack();
setVisible(true);
// End of constructor
//* actionPerformed:: This operation is call whenever the user click a button .All
// this operation does is pass on the text on the button to ' evt '
public void actionPerformed(ActionEvent evt)
String command = evt.getActionCommand();
StringBuffer tmp, first, second;
int value, size, k;
char ch, op = ' ';
first = new StringBuffer();
second = new StringBuffer();
//* processButton:This operation takes action according to the user's input. It is called
// from two other operation :actionPerformed ( when user click a button ) andkeypressed
// ( when user press a key on the keyboard ). This operation examines the text on the button
// by ( the parameter 'command') and calls the appropriate operation to process it
if ("CE".equals(command))
name.setText("");
else if("7".equals(command))
expression = name.getText();
name.setText(expression+"7");
else if ("8".equals(command))
expression = name.getText();
name.setText(expression+"8");
else if ("9".equals(command))
expression = name.getText();
name.setText(expression+"9");
else if("4".equals(command))
expression = name.getText();
name.setText(expression+"4");
else if("5".equals(command))
expression = name.getText();
name.setText(expression+"5");
else if("6".equals(command))
expression = name.getText();
name.setText(expression+"6");
else if("1".equals(command))
expression = name.getText();
name.setText(expression+"1");
else if("2".equals(command))
expression = name.getText();
name.setText(expression+"2");
else if("3".equals(command))
expression = name.getText();
name.setText(expression+"3");
else if("0".equals(command))
expression = name.getText();
name.setText(expression+"0");
else if("+".equals(command))
expression = name.getText();
name.setText(expression+"+");
else if("-".equals(command))
expression = name.getText();
name.setText(expression+"-");
else if("*".equals(command))
expression = name.getText();
name.setText(expression+"*");
else if("/".equals(command))
expression = name.getText();
name.setText(expression+"/");
//processEquals : Deal with the user clicking the '=' button. This operation finishes
// the most recent calculator
else if("=".equals(command))
expression = name.getText();
size = expression.length();
tmp = new StringBuffer( expression );
for(int i = 0;i<size;i++)
ch = tmp.charAt(i);
if(ch != '+' && ch != '*' && ch != '-' && ch != '/')
first . insert(i, ch);
else
op = ch;
k = 0;
for(int j = i+1; j< size ; j++)
ch = tmp.charAt(j);
second.insert(k,ch);
k++;
break;
switch(op)
//* processLastOperator : Carries out the arithmetic operation specified by the last
// operator, the last number and the number in the display.If the operator causes an
// error condition ( ex : the user tries to devide something by zero), this operation an
// exception     
// Question : if the user click on the button '2' , '+', '3' what values will found ?
case '+' : value = Integer.parseInt(new String(first)) +
Integer.parseInt(new String(second));
name.setText(new Integer(value).toString());
break;      // plus button
case '-' : value = Integer.parseInt(new String(first)) -
Integer.parseInt(new String(second));
name.setText(new Integer(value).toString());
break;
case '*' : value = Integer.parseInt(new String(first)) *
Integer.parseInt(new String(second));
name.setText(new Integer(value).toString());
break;
case '/' : value = Integer.parseInt(new String(first)) /
Integer.parseInt(new String(second));
name.setText(new Integer(value).toString());
break;
} //end of actionPerformed
/**main method to invoke from JVM.*/
public static void main(String args[])
new Calculator(); // Create a new instance of the Calculator object

Answer 1

Here's your code fixed up the enw way. It works the same, except it is half the size
package jExplorer;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
public class Calculator extends Frame implements ActionListener
  final static String[] bNames = {"7", "8", "9", "/", "sqrt", "CE", "4", "5", "6", "*", "%", "MS", "1", "2", "3", "-", "1/x", "M+", "0", "+/-", ".", "+", "=", "exit"};
  final static int NUM_BUTTONS = bNames.length;
  private TextField name;
* Calculator Constructor
* This operator constructor ( as with all constructors ) is executed when the new object
* is created. In this case we create all the buttons ( and the panels that contain them )
* then reset the calculator
  public Calculator()
    super( "DUSTPANTS CALCULATOR" );
    setLayout( new BorderLayout() );
    Panel p1 = new Panel();
    p1.setBackground( new Color( 18, 70, 1 ) );
    p1.setLayout( new FlowLayout() );
    Label aHeader;
    aHeader = new Label( "DUSTPANTS CALCULATOR" );
    aHeader.setFont( new Font( "Times New Roman", Font.BOLD, 24 ) );
    aHeader.setForeground( new Color( 255, 0, 0 ) );
    p1.add( aHeader );
// Question: what does 'North' mean here ?
// The applet places a GridLayout on the 'North' side
    add( "North", p1 );
    Panel p2 = new Panel();
    p2.setBackground( new Color( 27, 183, 100 ) );
    p2.setLayout( new GridLayout( 0, 1 ) );
    name = new TextField( 20 ); // Var for Text field max of 20 characters
    p2.add( name );
    add( "Center", p2 );
    Panel p3 = new Panel();
    p3.setLayout( new GridLayout( 0, 6 ) );
// Create buttons & their ActionListeners, and add them to the panel
    Button b[];
    b = new Button[NUM_BUTTONS];
    for( int x = 0; x < NUM_BUTTONS; x++ )
      b[x] = new Button( bNames[x] );
      b[x].addActionListener( this );
      p3.add( b[x] );
    add( "South", p3 );
    super.addWindowListener( new WindowAdapter()
      public void windowClosing( WindowEvent e )
        System.exit( 0 );
    setLocation( 200, 100 );
    pack();
    setVisible( true );
* actionPerformed:: This operation is call whenever the user click a button .All
* this operation does is pass on the text on the button to ' evt '
  public void actionPerformed( ActionEvent evt )
    String command = evt.getActionCommand();
    String expression;
    int value, size, k;
    char ch, op = ' ';
    StringBuffer tmp;
    StringBuffer first = new StringBuffer();
    StringBuffer second = new StringBuffer();
    if( "CE".equals( command ) )
      name.setText( "" );
    else if( "=".equals( command ) )
      expression = name.getText();
      tmp = new StringBuffer( expression );
      size = tmp.length();
      for( int i = 0; i < size; i++ )
        ch = tmp.charAt( i );
        if( ch != '+' && ch != '*' && ch != '-' && ch != '/' )
        { first.insert( i, ch ); }
        else
          op = ch;
          k = 0;
          for( int j = i + 1; j < size; j++ )
            ch = tmp.charAt( j );
            second.insert( k, ch );
            k++;
          break;
    else if( validButton( command ) )
      expression = name.getText();
      name.setText( expression + command );
    else
      Toolkit.getDefaultToolkit().beep();
   * processLastOperator : Carries out the arithmetic operation specified by the last
   * operator, the last number and the number in the display.If the operator causes an
   * error condition ( ex : the user tries to devide something by zero), this operation an
   * exception
   * Question : if the user click on the button '2' , '+', '3' what values will found ?
    switch( op )
      case '+':
        value = Integer.parseInt( new String( first ) ) +
          Integer.parseInt( new String( second ) );
        name.setText( new Integer( value ).toString() );
        break; // plus button
      case '-':
        value = Integer.parseInt( new String( first ) ) -
          Integer.parseInt( new String( second ) );
        name.setText( new Integer( value ).toString() );
        break;
      case '*':
        value = Integer.parseInt( new String( first ) ) *
          Integer.parseInt( new String( second ) );
        name.setText( new Integer( value ).toString() );
        break;
      case '/':
        value = Integer.parseInt( new String( first ) ) /
          Integer.parseInt( new String( second ) );
        name.setText( new Integer( value ).toString() );
        break;
  private static final boolean validButton( String command )
    for( int x = 0; x < NUM_BUTTONS; x++ )
      if( bNames[x].equals( command ) ) ;
        return true;
    return false;
  /** main method to invoke from JVM. */
  public static void main( String args[] )
    new Calculator(); // Create a new instance of the Calculator object
}