import java.applet.*;
public void init() {
d = getSize();
resize(d.width, d.height);
GridBagLayout g = new GridBagLayout();
setLayout(g);
GridBagConstraints gC = new GridBagConstraints();
// first row
gC = new GridBagConstraints();
gC.insets = new Insets(0, 0, 10, 0);
gC.gridy = 0;
gC.gridwidth = 5;
gC.fill = GridBagConstraints.BOTH;
txt = new JTextField();
txt.setHorizontalAlignment(JTextField.RIGHT);
txt.setEditable(false);
g.setConstraints(txt, gC);
add(txt);
// second row
gC = new GridBagConstraints();
gC.insets = new Insets(0, 0, 5, 0);
gC.gridy = 1;
gC.gridwidth = 1;
gC.fill = GridBagConstraints.BOTH;
b7 = new JButton("7");
b7.setForeground(Color.BLACK);
b7.addActionListener(new setLabelText_ActionListener());
g.setConstraints(b7, gC);
add(b7);
gC = new GridBagConstraints();
gC.fill = GridBagConstraints.HORIZONTAL;
gC.insets = new Insets(0, 5, 5, 0);
gC.gridy = 1;
gC.gridwidth = 1;
gC.fill = GridBagConstraints.BOTH;
b8 = new JButton("8");
b8.setForeground(Color.BLACK);
b8.addActionListener(new setLabelText_ActionListener());
g.setConstraints(b8, gC);
add(b8);
gC = new GridBagConstraints();
gC.insets = new Insets(0, 5, 5, 0);
gC.gridy = 1;
gC.gridwidth = 1;
gC.fill = GridBagConstraints.BOTH;
b9 = new JButton("9");
b9.setForeground(Color.BLACK);
b9.addActionListener(new setLabelText_ActionListener());
g.setConstraints(b9, gC);
add(b9);
gC = new GridBagConstraints();
gC.insets = new Insets(0, 5, 5, 0);
gC.gridy = 1;
gC.gridwidth = 1;
gC.fill = GridBagConstraints.BOTH;
bAdd = new JButton("+");
bAdd.setForeground(Color.BLUE);
bAdd.addActionListener(new setOperator_ActionListener());
g.setConstraints(bAdd, gC);
add(bAdd);
// third row
gC = new GridBagConstraints();
gC.insets = new Insets(0, 0, 5, 0);
gC.gridy = 2;
gC.gridwidth = 1;
gC.fill = GridBagConstraints.BOTH;
b4 = new JButton("4");
b4.setForeground(Color.BLACK);
b4.addActionListener(new setLabelText_ActionListener());
g.setConstraints(b4, gC);
add(b4);
gC = new GridBagConstraints();
gC.insets = new Insets(0, 5, 5, 0);
gC.gridy = 2;
gC.gridwidth = 1;
gC.fill = GridBagConstraints.BOTH;
b5 = new JButton("5");
b5.setForeground(Color.BLACK);
b5.addActionListener(new setLabelText_ActionListener());
g.setConstraints(b5, gC);
add(b5);
gC = new GridBagConstraints();
gC.insets = new Insets(0, 5, 5, 0);
gC.gridy = 2;
gC.gridwidth = 1;
gC.fill = GridBagConstraints.BOTH;
b6 = new JButton("6");
b6.setForeground(Color.BLACK);
b6.addActionListener(new setLabelText_ActionListener());
g.setConstraints(b6, gC);
add(b6);
gC = new GridBagConstraints();
gC.insets = new Insets(0, 5, 5, 0);
gC.gridy = 2;
gC.gridwidth = 1;
gC.fill = GridBagConstraints.BOTH;
bDec = new JButton("-");
bDec.setForeground(Color.BLUE);
bDec.addActionListener(new setOperator_ActionListener());
g.setConstraints(bDec, gC);
add(bDec);
gC = new GridBagConstraints();
gC.insets = new Insets(0, 5, 5, 0);
gC.gridy = 1;
gC.gridwidth = 1;
gC.gridheight = 2;
gC.fill = GridBagConstraints.BOTH;
bC = new JButton("C");
bC.setForeground(Color.RED);
bC.addActionListener(new setOperator_ActionListener());
g.setConstraints(bC, gC);
add(bC);
// fourth row
gC = new GridBagConstraints();
gC.insets = new Insets(0, 0, 5, 0);
gC.gridy = 3;
gC.gridwidth = 1;
gC.fill = GridBagConstraints.BOTH;
b1 = new JButton("1");
b1.setForeground(Color.BLACK);
b1.addActionListener(new setLabelText_ActionListener());
g.setConstraints(b1, gC);
add(b1);
gC = new GridBagConstraints();
gC.insets = new Insets(0, 5, 5, 0);
gC.gridy = 3;
gC.gridwidth = 1;
gC.fill = GridBagConstraints.BOTH;
b2 = new JButton("2");
b2.setForeground(Color.BLACK);
b2.addActionListener(new setLabelText_ActionListener());
g.setConstraints(b2, gC);
add(b2);
gC = new GridBagConstraints();
gC.insets = new Insets(0, 5, 5, 0);
gC.gridy = 3;
gC.gridwidth = 1;
gC.fill = GridBagConstraints.BOTH;
b3 = new JButton("3");
b3.setForeground(Color.BLACK);
b3.addActionListener(new setLabelText_ActionListener());
g.setConstraints(b3, gC);
add(b3);
gC = new GridBagConstraints();
gC.insets = new Insets(0, 5, 5, 0);
gC.gridy = 3;
gC.gridwidth = 1;
gC.fill = GridBagConstraints.BOTH;
bMul = new JButton("*");
bMul.setForeground(Color.BLUE);
bMul.addActionListener(new setOperator_ActionListener());
g.setConstraints(bMul, gC);
add(bMul);
// fifth row
gC = new GridBagConstraints();
gC.insets = new Insets(0, 0, 5, 0);
gC.gridy = 4;
gC.gridwidth = 2;
gC.fill = GridBagConstraints.BOTH;
b0 = new JButton("0");
b0.setForeground(Color.BLACK);
b0.addActionListener(new setLabelText_ActionListener());
g.setConstraints(b0, gC);
add(b0);
gC = new GridBagConstraints();
gC.insets = new Insets(0, 5, 5, 0);
gC.gridy = 4;
gC.gridwidth = 1;
gC.fill = GridBagConstraints.BOTH;
bPoint = new JButton(".");
bPoint.setForeground(Color.BLACK);
bPoint.addActionListener(new setLabelText_ActionListener());
g.setConstraints(bPoint, gC);
add(bPoint);
gC = new GridBagConstraints();
gC.insets = new Insets(0, 5, 5, 0);
gC.gridy = 4;
gC.gridwidth = 1;
gC.fill = GridBagConstraints.BOTH;
bDiv = new JButton("/");
bDiv.setForeground(Color.BLUE);
bDiv.addActionListener(new setOperator_ActionListener());
g.setConstraints(bDiv, gC);
add(bDiv);
gC = new GridBagConstraints();
gC.insets = new Insets(0, 5, 5, 0);
gC.gridy = 3;
gC.gridwidth = 1;
gC.gridheight = 2;
gC.fill = GridBagConstraints.BOTH;
bCal = new JButton("=");
bCal.addActionListener(new setOperator_ActionListener());
bCal.setForeground(Color.RED);
g.setConstraints(bCal, gC);
add(bCal);
}