import java.awt.*;
import java.awt.event.*;
import java.math.BigDecimal;

class Calculator {

 private Frame frame;

 private Panel panel[] = new Panel[6];

 private Button botton[] = new Button[25];

 private TextField textField;

 private final String string[] = { "1", "2", "3", "clear", "exit", "4", "5",
   "6", "+", "-", "7", "8", "9", "*", "/", "0", ".", "sqr", "%",
   "+/-", "sin", "cos", "tan", "PI", "=" };

 private String str1, str2, optype;

 private final Label label = new Label(
   "Contact me--QQ:120355282 , mail:fsolsh@gmail.com");

 private final String STR1 = "Please enter your data!";

 private final String STR2 = "Arithmetic data can't be '0'!";

 private double result = 0;

 private void go() {

  frame = new Frame("Welcome ! Author:Fsol-sh JSface");
  frame.setResizable(false);
  frame.setLayout(new GridLayout(7, 1, 5, 5));

  for (int i = 0; i < botton.length; i++) {
   botton[i] = new Button(string[i]);
   botton[i].setForeground(Color.BLUE);
   botton[i].setFont(new Font("", Font.BOLD, 12));
  }

  textField = new TextField(40);
  textField.setFont(new Font("", Font.BOLD, 12));
  textField.setEditable(false);

  label.setAlignment(1);
  label.setFont(new Font("", Font.BOLD, 12));
  label.setForeground(Color.BLUE);

  for (int i = 0; i < panel.length; i++) {
   panel[i] = new Panel();
   frame.add(panel[i]);
  }

  frame.add(label);

  panel[0].add(textField);

  for (int i = 1; i < 6; i++) {
   panel[i].setLayout(new GridLayout(1, 5, 5, 5));
   for (int j = (i - 1) * 5; j < i * 5; j++) {
    panel[i].add(botton[j]);
   }
  }

  for (int i = 0; i < 3; i++) {
   for (int j = (i) * 5; j < i * 5 + 3; j++) {
    buttonSet(botton[j]);
   }
  }

  botton[3].addActionListener(new ActionListener() {
   public void actionPerformed(ActionEvent e) {
    textField.setText("");
   }
  });

  botton[4].addActionListener(new ActionListener() {
   public void actionPerformed(ActionEvent e) {
    System.exit(0);
   }
  });

  operateTypeSet(botton[8]);
  operateTypeSet(botton[9]);
  operateTypeSet(botton[13]);
  operateTypeSet(botton[14]);
  operateTypeSet(botton[18]);

  botton[15].addActionListener(new ActionListener() {
   public void actionPerformed(ActionEvent e) {
    if (check(textField.getText())
      || textField.getText().equals("0")) {
     textField.setText("0");
    } else
     textField.setText(textField.getText() + "0");
   }
  });

  botton[16].addActionListener(new ActionListener() {
   public void actionPerformed(ActionEvent e) {
    if (check(textField.getText())) {
     textField.setText(STR1);
    } else if (textField.getText().indexOf(".") == -1) {
     textField.setText(textField.getText() + ".");
    } else
     textField.setText(textField.getText());
   }
  });

  botton[17].addActionListener(new ActionListener() {
   public void actionPerformed(ActionEvent e) {
    if (check(textField.getText())) {
     textField.setText(STR1);
    } else
     textField.setText(""
       + Math
         .sqrt(Double.parseDouble(textField
           .getText())));
   }
  });

  botton[19].addActionListener(new ActionListener() {
   public void actionPerformed(ActionEvent e) {
    String str = textField.getText();
    if (check(str)) {
     textField.setText(STR1);
    } else if (isZero(str)) {
     textField.setText(str);
    } else if (str.indexOf("-") != -1) {
     StringBuffer sb = new StringBuffer(str);
     sb = sb.deleteCharAt(sb.indexOf("-"));
     str = new String(sb);
     textField.setText(str);
    } else
     textField.setText("-" + str);
   }
  });

  botton[20].addActionListener(new ActionListener() {
   public void actionPerformed(ActionEvent e) {
    if (check(textField.getText())) {
     textField.setText(STR1);
    } else
     textField
       .setText(""
         + Math.sin(Double.parseDouble(textField
           .getText())));
   }
  });

  botton[21].addActionListener(new ActionListener() {
   public void actionPerformed(ActionEvent e) {
    if (check(textField.getText())) {
     textField.setText(STR1);
    } else
     textField
       .setText(""
         + Math.cos(Double.parseDouble(textField
           .getText())));
   }
  });

  botton[22].addActionListener(new ActionListener() {
   public void actionPerformed(ActionEvent e) {
    if (check(textField.getText())) {
     textField.setText(STR1);
    } else
     textField
       .setText(""
         + Math.tan(Double.parseDouble(textField
           .getText())));
   }
  });

  botton[23].addActionListener(new ActionListener() {
   public void actionPerformed(ActionEvent e) {
    textField.setText("" + Math.PI);
   }
  });

  botton[24].addActionListener(new ActionListener() {
   public void actionPerformed(ActionEvent e) {
    str2 = textField.getText();
    if (check(str2)) {
     textField.setText(STR1);
    } else if (isZero(str2) && "/".equals(optype)) {
     textField.setText(STR2);
    } else {
     operate(str1, str2);
     textField.setText("" + result);
     str1 = "";
     str2 = "";
     optype = "=";
    }
   }
  });

  frame.addWindowListener(new WindowAdapter() {
   public void windowClosing(WindowEvent e) {
    System.exit(0);
   }
  });

  frame.pack();
  frame.setVisible(true);
 }

 private void operateTypeSet(final Button opbutton) {
  opbutton.addActionListener(new ActionListener() {
   public void actionPerformed(ActionEvent e) {
    str1 = textField.getText();
    if (check(str1)) {
     str1 = "";
     optype = null;
     textField.setText(STR1);
    } else {
     textField.setText("");
     optype = opbutton.getLabel();
    }
   }
  });
 }

 private void buttonSet(final Button b) {
  b.addActionListener(new ActionListener() {
   public void actionPerformed(ActionEvent e) {
    if (check(textField.getText())) {
     textField.setText(b.getLabel());
    } else {
     textField.setText(textField.getText() + b.getLabel());
    }
   }
  });
 }

 private boolean check(String param) {
  return isNullOrEmpty(param) || STR1.equals(param) || STR2.equals(param);
 }

 private boolean isZero(String param) {
  if (!isNullOrEmpty(param)) {
   BigDecimal bigDecimal = new BigDecimal(param);
   return bigDecimal.compareTo(new BigDecimal(0)) == 0;
  } else {
   return false;
  }
 }

 private boolean isNullOrEmpty(String param) {
  return param == null || param.trim().length() == 0;
 }

 private double operate(String param1, String param2) {
  if (optype == "+") {
   result = Double.parseDouble(param1) + Double.parseDouble(param2);
  } else if (optype == "-") {
   result = Double.parseDouble(param1) - Double.parseDouble(param2);
  } else if (optype == "*") {
   result = Double.parseDouble(param1) * Double.parseDouble(param2);
  } else if (optype == "/") {
   result = Double.parseDouble(param1) / Double.parseDouble(param2);
  } else if (optype == "%") {
   result = Double.parseDouble(param1) % Double.parseDouble(param2);
  } else {
   result = Double.parseDouble(param2);
  }
  return this.result;
 }

 public static void main(String[] args) {
  Calculator calculator = new Calculator();
  calculator.go();
 }
}