Swing:-
In Java programming language we can develop desktop GUI applications in 2 ways:i) AWT (Abstract Window Toolkit)
ii) JFC & Swings (In sun microsystems the project which developed JFC classes is named Swings project).
Difference between AWT and JFC & Swings are:
i) AWT components are heavy weight
Swings components are light weight
ii) Because of heavy weight AWT components execute faster than Swing components
iii) Heavy weight mean that the functions exist in AWT access GUI API of OS. For instance in Windows OS AWT classes accesses MFC library (mfc32.dll), on Linux LFC and on Solaris SFC classes are accessed by AWT components.
Because by the time we call Button("OK") class constructor that will access WinToolkit API, that access precompiled functions in Win32.dll, the moment they are called the component immediately comes out on to screen.
But in Swings when we call JButton("OK"), the constructor instantly constructs the component hence each component instant construction takes lot of time to execute in Swings.
iv) If any GUI appl developed in AWT the layout remains same but the look and feel of awt components differ from OS to OS.
But GUI application developed in Swings remains constant across all OSs.
v) AWT has access to basic GUI components only, because they support GUI components that are supported by all OSs.
Swings has their own GUI library, all Rich UI components supported all front end tools (VB, PB, Oracle Developer/Designer 2000) are developed in swings project.
Component
1. JMenu2. JTabbedPane
3. JTable
4. JTree
5. JContentPane
6. JSplitPane
7. JSpinner
8. JSlider
// CalculatorApplication.java
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.text.*;
public class CalculatorApplication extends JFrame implements ActionListener {
JTextField resultField;
double operandOne;
double operandTwo;
int operator;
JButton addButton;
JButton subtractButton;
JButton multiplyButton;
JButton divideButton;
JButton percentileButton;
JButton equalsButton;
JButton dotButton;
JButton cancelButton;
JButton onebyButton;
JButton backButton;
JButton one1;
JButton two2;
JButton three3;
JButton four4;
JButton five5;
JButton six6;
JButton seven7;
JButton eight8;
JButton nine9;
JButton zero0;
Object source;
public static void main(String[] args) {
CalculatorApplication app = new CalculatorApplication();
app.addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent we) {
System.exit(0);
}
});
app.setSize(280, 240);
app.setVisible(true);
}
public CalculatorApplication() {
super();
JPanel operandPanel;
JPanel buttonPanel1;
JPanel buttonPanel2;
JPanel buttonPanel3;
JPanel buttonPanel4;
Container cp;
cp = getContentPane();
cp.setLayout(new GridLayout(5, 1));
operandPanel = new JPanel();
operandPanel.setLayout(new FlowLayout());
resultField = new JTextField("0", 23);
resultField.setHorizontalAlignment(SwingConstants.RIGHT);
operandPanel.add(resultField);
cp.add(operandPanel);
buttonPanel1 = new JPanel();
buttonPanel1.setLayout(new FlowLayout());
seven7 = new JButton(" 7 ");
seven7.addActionListener(this);
buttonPanel1.add(seven7);
eight8 = new JButton(" 8 ");
eight8.addActionListener(this);
buttonPanel1.add(eight8);
nine9 = new JButton(" 9 ");
nine9.addActionListener(this);
buttonPanel1.add(nine9);
divideButton = new JButton(" / ");
divideButton.addActionListener(this);
buttonPanel1.add(divideButton);
cancelButton = new JButton(" C ");
cancelButton.addActionListener(this);
buttonPanel1.add(cancelButton);
cp.add(buttonPanel1);
buttonPanel2 = new JPanel();
buttonPanel2.setLayout(new FlowLayout());
four4 = new JButton(" 4 ");
four4.addActionListener(this);
buttonPanel2.add(four4);
five5 = new JButton(" 5 ");
five5.addActionListener(this);
buttonPanel2.add(five5);
six6 = new JButton(" 6 ");
six6.addActionListener(this);
buttonPanel2.add(six6);
multiplyButton = new JButton(" * ");
multiplyButton.addActionListener(this);
buttonPanel2.add(multiplyButton);
backButton = new JButton(" B ");
backButton.addActionListener(this);
buttonPanel2.add(backButton);
cp.add(buttonPanel2);
buttonPanel3 = new JPanel();
buttonPanel3.setLayout(new FlowLayout());
one1 = new JButton(" 1 ");
one1.addActionListener(this);
buttonPanel3.add(one1);
two2 = new JButton(" 2 ");
two2.addActionListener(this);
buttonPanel3.add(two2);
three3 = new JButton(" 3 ");
three3.addActionListener(this);
buttonPanel3.add(three3);
subtractButton = new JButton(" - ");
subtractButton.addActionListener(this);
buttonPanel3.add(subtractButton);
onebyButton = new JButton("1/x");
onebyButton.addActionListener(this);
buttonPanel3.add(onebyButton);
cp.add(buttonPanel3);
buttonPanel4 = new JPanel();
buttonPanel4.setLayout(new FlowLayout());
zero0 = new JButton(" 0 ");
zero0.addActionListener(this);
buttonPanel4.add(zero0);
dotButton = new JButton(" . ");
dotButton.addActionListener(this);
buttonPanel4.add(dotButton);
percentileButton = new JButton(" % ");
percentileButton.addActionListener(this);
buttonPanel4.add(percentileButton);
addButton = new JButton(" + ");
addButton.addActionListener(this);
buttonPanel4.add(addButton);
equalsButton = new JButton(" = ");
equalsButton.addActionListener(this);
buttonPanel4.add(equalsButton);
cp.add(buttonPanel4);
}
public void showResult() {
boolean validOperands;
DecimalFormat df = new DecimalFormat("0.00");
try {
// operandOne = Double.parseDouble(operandOneField.getText());
// operandTwo = Double.parseDouble(operandTwoField.getText());
validOperands = true;
} catch(NumberFormatException nfe) {
validOperands = false;
}
if (validOperands) {
if (source == addButton) {
operandOne =Double.parseDouble(resultField.getText());
resultField.setText("0");
operator = 1;
}
else if (source == subtractButton) {
operandOne =Double.parseDouble(resultField.getText());
resultField.setText("0");
operator = 2;
}
else if (source == multiplyButton) {
operandOne = Double.parseDouble(resultField.getText());
resultField.setText("0");
operator = 3;
}
else if (source == divideButton) {
operandOne = Double.parseDouble(resultField.getText());
resultField.setText("0");
operator = 4;
}
else if (source == percentileButton) {
operandOne =Double.parseDouble(resultField.getText());
resultField.setText("0");
operator = 5;
}
else if (source == equalsButton) {
operandTwo = Double.parseDouble(resultField.getText());
switch(operator){
case 1:
resultField.setText(Double.toString(operandOne + operandTwo));
operandOne = 0.0;
operandTwo = 0.0;
break;
case 2:
resultField.setText(Double.toString(operandOne - operandTwo));
operandOne = 0.0;
operandTwo = 0.0;
break;
case 3:
resultField.setText(Double.toString(operandOne * operandTwo));
operandOne = 0.0;
operandTwo = 0.0;
break;
case 4:
if (operandTwo != 0.0){
resultField.setText(Double.toString(operandOne / operandTwo));
operandOne = 0.0;
operandTwo = 0.0;}
else{
resultField.setText("0");}
break;
case 5:
resultField.setText(Double.toString(operandOne % operandTwo));
operandOne = 0.0;
operandTwo = 0.0;
}
}
else if (source == onebyButton) {
if (resultField.getText().equals("0"))
resultField.setText("0");
else
resultField.setText(Double.toString(1.0 / Double.parseDouble(resultField.getText())));
}
else if (source == one1) {
if (resultField.getText().equals("0"))
resultField.setText("1");
else
resultField.setText(resultField.getText() + "1");
}
else if (source == two2) {
if (resultField.getText().equals("0"))
resultField.setText("2");
else
resultField.setText(resultField.getText() + "2");
}
else if (source == three3) {
if (resultField.getText().equals("0"))
resultField.setText("3");
else
resultField.setText(resultField.getText() + "3");
}
else if (source == four4) {
if (resultField.getText().equals("0"))
resultField.setText("4");
else
resultField.setText(resultField.getText() + "4");
}
else if (source == five5) {
if (resultField.getText().equals("0"))
resultField.setText("5");
else
resultField.setText(resultField.getText() + "5");
}
else if (source == six6) {
if (resultField.getText().equals("0"))
resultField.setText("6");
else
resultField.setText(resultField.getText() + "6");
}
else if (source == seven7) {
if (resultField.getText().equals("0"))
resultField.setText("7");
else
resultField.setText(resultField.getText() + "7");
}
else if (source == eight8) {
if (resultField.getText().equals("0"))
resultField.setText("8");
else
resultField.setText(resultField.getText() + "8");
}
else if (source == nine9) {
if (resultField.getText().equals("0"))
resultField.setText("9");
else
resultField.setText(resultField.getText() + "9");
}
else if (source == zero0) {
if (resultField.getText().equals("0"))
resultField.setText("0");
else
resultField.setText(resultField.getText() + "0");
}
else if (source == dotButton) {
if (resultField.getText().equals("0"))
resultField.setText("0.");
else if (resultField.getText().indexOf('.') == -1){
resultField.setText(resultField.getText() + ".");
}
else{}
}
else if (source == cancelButton) {
resultField.setText("0");
}
else if (source == backButton) {
if (!(resultField.getText().equals("0") || resultField.getText().equals("0.0")) && resultField.getText().length() > 1){
resultField.setText(resultField.getText().substring(0,resultField.getText().length()-1));
}
}
} else
resultField.setText("Invalid operand");
}
public void actionPerformed(ActionEvent ae) {
source = ae.getSource();
showResult();
}
}
