/*
 *
 * Title: The Calculator (Basic AWT)
 * written by: Arthur Y. Gapusan    
 * Date Finished: May 2, 2004          
 * email: ajgapusan@hotmail.com, 
 *
 *   + No Layouts! Bunch of setBounds methods...
 *
 * http://www.planet-java.biz.ly
 */

import java.awt.*;
import java.applet.*;
import java.awt.event.*;
import java.util.*;

class Calculator extends Frame
  implements ActionListener {

  TextField tf; 
  Button b[] = new Button[10];
  Button dot, equals;
  Button add, sub, mul, div, sqrt, sqr, inverse;
  Button back, clear, m_in, m_out, m_clear; 
  Button ok;

  String str;
  String op, lastOperation;
  
  double memory = 0;
  double ans, num1 = 0, num2 = 0;
  boolean ready = false, performed = false;
  
  Calculator(String s) {
    setLayout(null);
    setTitle(s);
    tf = new TextField();
    tf.setFont(new Font("Dialog", Font.BOLD, 25));
    tf.setBackground(new Color(90,90,90));
    tf.setForeground(Color.white);
    tf.setBounds(30, 50, 269, 35);
    add(tf);
    tf.addActionListener(this);

    clear = new Button("C");
    change(clear, 20);
    add(clear);
    clear.setForeground(new Color(245, 50, 50));
    clear.setBounds(305, 53, 50, 30);
    clear.addActionListener(this);    

    for (int i=0;i<10;i++) {
      b[i] = new Button("" + i);
      change(b[i], 20);
      add(b[i]);
      b[i].addActionListener(this);
    }
    dot = new Button(".");
    change(dot, 20);
    add(dot);
    dot.addActionListener(this);
    equals = new Button("=");
    change(equals, 20);
    add(equals);
    equals.addActionListener(this);
    add = new Button("+");
    change(add, 20);
    add(add);
    add.addActionListener(this);
    sub = new Button("-");
    change(sub, 20);
    add(sub);
    sub.addActionListener(this);
    mul = new Button("*");
    change(mul, 20);
    add(mul);
    mul.addActionListener(this);
    div = new Button("/");
    change(div, 20);
    add(div);
    div.addActionListener(this);

    sqr = new Button("x^2");
    change(sqr, 15);
    add(sqr);
    sqr.addActionListener(this);
    sqrt = new Button("sqrt");
    change(sqrt, 15);
    add(sqrt);
    sqrt.addActionListener(this);
    inverse = new Button("1/x");
    change(inverse, 15);
    add(inverse);
    inverse.addActionListener(this);
    back = new Button("Backspace");
    change(back, 15);
    back.setForeground(new Color(230, 230, 230));
    add(back);
    back.addActionListener(this);
    m_in = new Button("M+");
    change(m_in, 20);
    add(m_in);
    m_in.addActionListener(this);
    m_out = new Button("MR");
    change(m_out, 20);
    add(m_out);
    m_out.addActionListener(this);
    m_clear = new Button("MC");
    change(m_clear, 20);
    add(m_clear);
    m_clear.addActionListener(this);

    b[7].setBounds(30, 100, 50, 30);
    b[8].setBounds(85, 100, 50, 30);
    b[9].setBounds(140, 100, 50, 30);
    add.setBounds(195, 100, 50, 30);
    sub.setBounds(250, 100, 50, 30);
    m_clear.setBounds(305, 100, 50, 30);

    b[4].setBounds(30, 135, 50, 30);
    b[5].setBounds(85, 135, 50, 30);
    b[6].setBounds(140, 135, 50, 30);
    mul.setBounds(195, 135, 50, 30);
    div.setBounds(250, 135, 50, 30);
    m_in.setBounds(305, 135, 50, 30);

    b[1].setBounds(30, 170, 50, 30);
    b[2].setBounds(85, 170, 50, 30);
    b[3].setBounds(140, 170, 50, 30);
    sqr.setBounds(195, 170, 50, 30);
    sqrt.setBounds(250, 170, 50, 30);
    m_out.setBounds(305, 170, 50, 30);

    b[0].setBounds(30, 205, 50, 30);
    dot.setBounds(85, 205, 50, 30);
    equals.setBounds(140, 205, 50, 30);
    inverse.setBounds(195, 205, 50, 30);
    back.setBounds(250, 205, 105, 30);
    
    Label l[] = new Label[2];
    l[0] = new Label("by: Arthur Y. Gapusan");
    l[1] = new Label("Copyright(C) 2004");
    for (int i=0;i<2;i++) {
      l[i].setFont(new Font("TimesRoman", Font.BOLD, 10));
      l[i].setForeground(new Color(35, 35, 35));
      l[i].setBackground(new Color(65, 65, 65));      
      add(l[i]);
    }
    l[0].setBounds(30, 238, 120, 10);
    l[1].setBounds(273, 238, 85, 10);
    
    addWindowListener(new Window());
  }


  public void change(Button b, int size) {
    b.setBackground(new Color(40, 40, 40));
    b.setForeground(new Color(150, 150, 150));
    b.setFont(new Font("SansSerif", Font.BOLD, size));
  }
  
  
  
                   // |----------------------|                                      
                   // |     Action Event     |
                   // |----------------------|
               
                 


  public void actionPerformed(ActionEvent ae) {
    if (ae.getSource() == clear) {
      tf.setText("");
      str = ""; op = ""; lastOperation = "";
      ans = 0; num1 = 0; num2 = 0;    
      ready = false; performed = false;  
    }

    str = tf.getText();
    int len = str.length();
    if (ae.getSource() == back) {
      String newString = "";
      for (int i=0;i<len-1;i++) {
        char chr = str.charAt(i);
        newString = newString + chr;
        }
      str = newString;      
      tf.setEditable(true);
      tf.setText(str);
    }
    if (str.length() == 30) {
      closed();
    }        
    
    
                    // |----------------------|
                    // |       Memory         |
                    // |----------------------|
    
    

    if (ae.getSource() == m_in) {
      try {
        memory = Double.parseDouble(str);
        m_in.setForeground(Color.green);
      } catch (NumberFormatException e) {
          if (memory != 0);
          else
            m_in.setForeground(new Color(150, 150, 159));
        }
    }
    if (ae.getSource() == m_out) {
      if (memory == 0);
      else {
      	 if (performed) {
          ready = true;
          lastOperation = op;
          tf.setText("");
          performed = false;
          tf.setText(String.valueOf(memory));
        }
        else {
      	  tf.setText("");
          tf.setText(str + String.valueOf(memory));
        }    
      }
    }
    if (ae.getSource() == m_clear) {
      memory = 0;
      m_in.setForeground(new Color(150, 150, 150));
    }
    
    
                     // |-------------------------|
                     // |    SetText(Numbers)     |
                     // |-------------------------|
    
    

    for (int i=0;i<10;i++) 
      if (ae.getSource() == b[i]) { 
        if (performed) {
          ready = true;
          lastOperation = op;
          tf.setText("");
          performed = false;
        }
        str = tf.getText();
        tf.setText(str + "" + i);            
      }
    if (ae.getSource() == dot) 
      tf.setText(str + ".");
    
     
  

                 //  |-----------------------|
                 //  |   SQRTs, SQR, etc..   |
                 //  |-----------------------|



    if (ae.getSource() == sqr) {
      testString();
      double r = toDouble();
      ans = Math.pow(r, 2);
      tf.setText("" + ans);       
      closed();
    }    
    if (ae.getSource() == sqrt) {    
      testString();
      double r = toDouble();
      ans = Math.sqrt(r);
      tf.setText("" + ans);     
      closed();
    }
    if (ae.getSource() == inverse) {
      testString();   
      double r = toDouble();
      ans = (1 / r);
      tf.setText("" + ans);
      closed(); 
    }
    
    
    
    
    
                   // |---------------------|
                   // |   Four Operations   |
                   // |---------------------|
    
    
    
    
         
    if (ae.getSource() == add) {      
      if (ready) {
      	num2 = toDouble();
        ans = check(lastOperation, num1, num2);
        tf.setText(String.valueOf(ans));
        ready = false;
  /**/  num1 = toDouble();
        op = "addition";
  /**/  performed = true;
        closed();
      }
      else {
      	testString();
      	num1 = toDouble();
        op = "addition";
        performed = true;
      }               
    }
    
    if (ae.getSource() == sub) {      
      if (ready) {
      	num2 = toDouble();
        ans = check(lastOperation, num1, num2);
        tf.setText(String.valueOf(ans));
        ready = false;
  /**/  num1 = toDouble();
        op = "subtraction";
        performed = true;
        closed();
      }
      else {
      	testString();
      	num1 = toDouble();
        op = "subtraction";
        performed = true;
      }               
    }
    
    if (ae.getSource() == mul) {      
      if (ready) {
      	num2 = toDouble();
        ans = check(lastOperation, num1, num2);
        tf.setText(String.valueOf(ans));
        ready = false;
  /**/  num1 = toDouble();
        op = "multiplication";
        performed = true;
        closed();      
      }
      else {
      	testString();
      	num1 = toDouble();
        op = "multiplication";
        performed = true;
      }               
    }
    
    if (ae.getSource() == div) {            
      if (ready) {
      	num2 = toDouble();
        ans = check(lastOperation, num1, num2);
        tf.setText(String.valueOf(ans));
        ready = false;
  /**/  num1 = toDouble();
        op = "division";
        performed = true;
        closed();
      }
      else {
      	testString();
      	num1 = toDouble();
        op = "division";
        performed = true;
      }               
    }
    
    if ((ae.getSource() == equals) || (ae.getSource() == tf)) {
      if (ready) {
        try {
          num2 = toDouble();
          ans = check(op, num1, num2);
          tf.setText(String.valueOf(ans));
          performed = false;
          ready = false;
          closed();
        } catch (NumberFormatException e) {
      	  tf.setText("Error 1");
      	}      
      }
    }
  }



             // |--------------------|             
             // |      Methods       |
             // |--------------------|
             
             
             
   
  double check(String op, double num1, double num2) {
    if (op.equals("addition"))
      return (num1 + num2);
    if (op.equals("subtraction"))
      return (num1 - num2);
    if (op.equals("multiplication"))
      return (num1 * num2);
    else
      return (num1 / num2);
  }
   
  public double toDouble() {
    double r = 0;
    try {
      str = tf.getText();
      Double d = new Double(str);
      r = d.doubleValue(); 
    } catch (NumberFormatException e) { 
        tf.setText("Error 2"); 
      }
    return r;
  }

  public void closed() {
    tf.setEditable(false);
    tf.setBackground(new Color(90,90,90));
  }
  public void testString() {
    String test = tf.getText();
    if (test.length()<1)
      tf.setText("0");
  }
  
  
                
                //  |------------------------|
                //  |         PAINT          | 
                //  |------------------------|
             
  
  

  public void paint(Graphics g) {
    int startX = 4;
    int startY = 23;
    int i=0;
    for ( ;i<4;i++) {
      g.setColor(new Color(55+i*20,55+i*20,55+i*20));
      g.fillRoundRect(startX + i, startY + i, 360, 225, 15, 15);
    }
    for (int k=8;k>3;k--, i++) {
      g.setColor(new Color(25+k*20,25+k*20,25+k*20));
      g.fillRoundRect(startX + i, startY + i, 360, 225, 15, 15);
    }
    g.setColor(new Color(65,65,65));
    g.fillRoundRect((startX + i) - 1, (startY + i) - 1, 360, 225, 15, 15);
  }

  public static void main(String args[]) {
    Calculator c = new Calculator("The Calculator");
    c.setSize(378, 261);
    c.setVisible(true);
    c.setResizable(false);
  }
}

class Window extends WindowAdapter {
  public void windowClosing(WindowEvent we) {
    System.exit(0);
  }
}