import java.awt.*;
import java.awt.FlowLayout;
import java.awt.event.*;
import java.awt.Color.*;
import java.awt.image.*;


import javax.swing.*;
import javax.swing.border.*;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;



public class Calculator extends JFrame implements ActionListener{

	final int MAX_INPUT_LENGTH = 31;
	final int INPUT_MODE = 0;
	final int RESULT_MODE = 1;
	final int ERROR_MODE = 2;
	int displayMode;

	// variables for memory buttons functionality
    static double m1, m2;
	int k = 1;
	JButton butM1, butM2, butM3, butM4;


	double lastNumber;
	boolean clearOnNextDigit, percent;
	String lastOperator;


	JButton but0, but1, but2, but3, but4, but5, but6, but7, but8, but9, but10, but11, but12, but13, but14, but15, but16, but17, but18, but19, but20, but21, but22;

	JMenu jmenuEdit, jmenuView, jmenuHelp;
	JMenuItem jmenuitemCopy, jmenuitemPaste, jmenuitemStandard, jmenuitemScientific, jmenuitemDigit, jmenuitemHelp, jmenuitemAbout;

    Border raisedbevel, loweredbevel, border;


	JLabel MemoryTextfield, LabelOutPut;



	public Calculator()
	{
		setBackground(new Color(236,233,216));
		setIconImage(new ImageIcon("6039.png").getImage());


 		border = LineBorder.createGrayLineBorder();
		raisedbevel = BorderFactory.createRaisedBevelBorder();
        loweredbevel = BorderFactory.createLoweredBevelBorder();

		Font f12 = new Font("MS Shell Dlg", 0, 11);
		Font f121 = new Font("MS Shell Dlg", 0, 12);



	/*Edit menu*/
		jmenuEdit = new JMenu("Edit");
		jmenuEdit.setFont(f12);
		jmenuEdit.setMnemonic(KeyEvent.VK_F);


		jmenuitemCopy = new JMenuItem("    Copy");
		jmenuitemCopy.setFont(f121);
		jmenuitemCopy.setAccelerator(KeyStroke.getKeyStroke( KeyEvent.VK_C,
													ActionEvent.CTRL_MASK));
		jmenuitemPaste = new JMenuItem("    Paste");
		jmenuitemPaste.setFont(f121);
		jmenuitemPaste.setAccelerator(KeyStroke.getKeyStroke( KeyEvent.VK_V,
													ActionEvent.CTRL_MASK));
		jmenuEdit.add(jmenuitemCopy);
		jmenuEdit.add(jmenuitemPaste);


	/*View menu*/


		jmenuView = new JMenu("View");
		jmenuView.setFont(f12);
		jmenuView.setMnemonic(KeyEvent.VK_H);

		jmenuitemStandard = new JMenuItem("    Standard");
		jmenuitemStandard.setFont(f121);

		jmenuitemScientific = new JMenuItem("    Scientific");
		jmenuitemScientific.setFont(f121);

		jmenuitemDigit = new JMenuItem("    Digital grouping");
		jmenuitemDigit.setFont(f121);

		jmenuView.add(jmenuitemStandard);
		jmenuView.add(jmenuitemScientific);
		jmenuView.add(jmenuitemDigit);


	/*Help menu*/


		jmenuHelp = new JMenu("Help");
		jmenuHelp.setFont(f12);
		jmenuHelp.setMnemonic(KeyEvent.VK_H);

		jmenuitemHelp = new JMenuItem("    Help Topics");
		jmenuitemHelp.setFont(f121);
		jmenuitemHelp.addActionListener(this);

		jmenuitemAbout = new JMenuItem("    About calculator");
		jmenuitemAbout.setFont(f121);
		jmenuitemAbout.addActionListener(this);

		jmenuHelp.add(jmenuitemHelp);
		jmenuHelp.add(jmenuitemAbout);



		JMenuBar mb = new JMenuBar();
		mb.add(jmenuEdit);
		mb.add(jmenuView);
		mb.add(jmenuHelp);
		//setJMenuBar(mb);




		// Add components to frame
		add(mb,BorderLayout.NORTH);



		JPanel jplBackSpace, jplControl, jplButtons;

		jplButtons = new JPanel();
		// Set jplButton panel layout manager for a 4 by 5 grid
		jplButtons.setLayout(new GridLayout(4, 5, 6, 6));
		jplButtons.setBorder(new EmptyBorder(4, 12, 0, 0));





		// Create numeric Jbuttons
		but1 = new JButton("1");
		but1.setMargin(new Insets(0, 0, 0, 0));
		but1.setFont(f12);
		but1.setForeground(Color.blue);
		but1.setBackground(new Color(242,243,238));
		but1.setBorder(new RoundedBorder(10));
		but1.addActionListener(this);



		but2 = new JButton("2");
		but2.setMargin(new Insets(0, 0, 0, 0));
		but2.setFont(f12);
		but2.setForeground(Color.blue);
		but2.setBackground(new Color(242,243,238));
		but2.addActionListener(this);


		but3 = new JButton("3");
		but3.setMargin(new Insets(0, 0, 0, 0));
		but3.setFont(f12);
		but3.setForeground(Color.blue);
		but3.setBackground(new Color(242,243,238));
		but3.addActionListener(this);

		but4 = new JButton("4");
		but4.setMargin(new Insets(0, 0, 0, 0));
		but4.setFont(f12);
		but4.setForeground(Color.blue);
		but4.setBackground(new Color(242,243,238));
		but4.addActionListener(this);

		but5 = new JButton("5");
		but5.setMargin(new Insets(0, 0, 0, 0));
		but5.setFont(f12);
		but5.setForeground(Color.blue);
		but5.setBackground(new Color(242,243,238));
		but5.addActionListener(this);

		but6 = new JButton("6");
		but6.setMargin(new Insets(0, 0, 0, 0));
		but6.setFont(f12);
		but6.setForeground(Color.blue);
		but6.setBackground(new Color(242,243,238));
		but6.addActionListener(this);

		but7 = new JButton("7");
		but7.setMargin(new Insets(0, 0, 0, 0));
		but7.setFont(f12);
		but7.setForeground(Color.blue);
		but7.setBackground(new Color(242,243,238));
		but7.addActionListener(this);

		but8 = new JButton("8");
		but8.setMargin(new Insets(0, 0, 0, 0));
		but8.setFont(f12);
		but8.setForeground(Color.blue);
		but8.setBackground(new Color(242,243,238));
		but8.addActionListener(this);

		but9 = new JButton("9");
		but9.setMargin(new Insets(0, 0, 0, 0));
		but9.setFont(f12);
		but9.setForeground(Color.blue);
		but9.setBackground(new Color(242,243,238));
		but9.addActionListener(this);

		but0 = new JButton("0");
		but0.setMargin(new Insets(0, 0, 0, 0));
		but0.setFont(f12);
		but0.setForeground(Color.blue);
		but0.setBackground(new Color(242,243,238));
		but0.addActionListener(this);


		// Create operator Jbuttons
		but10 = new JButton("+/-");
		but10.setMargin(new Insets(0, 0, 0, 0));
		but10.setFont(f12);
		but10.setForeground(Color.blue);
		but10.setBackground(new Color(242,243,238));
		but10.addActionListener(this);

		but11 = new JButton(".");
		but11.setMargin(new Insets(0, 0, 0, 0));
		but11.setFont(f12);
		but11.setForeground(Color.blue);
		but11.setBackground(new Color(242,243,238));
		but11.addActionListener(this);

		but12 = new JButton("=");
		but12.setMargin(new Insets(0, 0, 0, 0));
		but12.setFont(f12);
		but12.setForeground(Color.red);
		but12.setBackground(new Color(242,243,238));
		but12.addActionListener(this);

		but13 = new JButton("/");
		but13.setMargin(new Insets(0, 0, 0, 0));
		but13.setFont(f12);
		but13.setForeground(Color.red);
		but13.setBackground(new Color(242,243,238));
		but13.addActionListener(this);

		but14 = new JButton("*");
		but14.setMargin(new Insets(0, 0, 0, 0));
		but14.setFont(f12);
		but14.setForeground(Color.red);
		but14.setBackground(new Color(242,243,238));
		but14.addActionListener(this);


		but15 = new JButton("-");
		but15.setFont(f12);
		but15.setForeground(Color.red);
		but15.setMargin(new Insets(0, 0, 0, 0));
		but15.setBackground(new Color(242,243,238));
		but15.addActionListener(this);

		but16 = new JButton("+");
		but16.setFont(f12);
		but16.setForeground(Color.red);
		but16.setMargin(new Insets(0, 0, 0, 0));
		but16.setBackground(new Color(242,243,238));
		but16.addActionListener(this);


		but17 = new JButton("sqrt");
		but17.setFont(f12);
		but17.setForeground(Color.blue);
		but17.setMargin(new Insets(0, 0, 0, 0));
		but17.setBackground(new Color(242,243,238));
		but17.addActionListener(this);


		but18 = new JButton("1/x");
		but18.setFont(f12);
		but18.setForeground(Color.blue);
		but18.setMargin(new Insets(0, 0, 0, 0));
		but18.setBackground(new Color(242,243,238));
		but18.addActionListener(this);


		but19 = new JButton("%");
		but19.setFont(f12);
		but19.setForeground(Color.blue);
		but19.setMargin(new Insets(0, 0, 0, 0));
		but19.setBackground(new Color(242,243,238));
		but19.addActionListener(this);

		//panel is the main Jpanel, so it contains jplControl, jplControl2, JButtons
		JPanel panel = new JPanel(new BorderLayout(0, 0));
		getContentPane().add(panel, BorderLayout.CENTER);
		panel.setBorder(new EmptyBorder(3, 9, 10, 9));
		// panel.setBackground(Color.yellow);



 //output numbers, result of calculations
		LabelOutPut = new JLabel("0");



		LabelOutPut.setHorizontalAlignment(JLabel.RIGHT);
		LabelOutPut.setBackground(Color.WHITE);
		LabelOutPut.setFont(f121);
		LabelOutPut.setOpaque(true);
		LabelOutPut.setPreferredSize(new Dimension(200,23));
		LabelOutPut.setBorder(loweredbevel);


		panel.add(LabelOutPut, BorderLayout.NORTH);
		/*
		JFormattedTextField formattedTextField = new JFormattedTextField();
		panel.add(formattedTextField, BorderLayout.NORTH);
		formattedTextField.setHorizontalAlignment(JFormattedTextField.RIGHT);
		formattedTextField.setPreferredSize(new Dimension(105,22));

		panel.add(formattedTextField,BorderLayout.NORTH);
*/



		//text field for MC, MR, MS, M+
		/*
		JFormattedTextField MemoryTextfield = new JFormattedTextField();
		MemoryTextfield.setBackground(new Color(237,237,237));
		MemoryTextfield.setPreferredSize(new Dimension(27,26));
		*/


		MemoryTextfield = new JLabel("");

		MemoryTextfield.setHorizontalAlignment(JLabel.CENTER);
		MemoryTextfield.setBackground(new Color(237,237,237));
		MemoryTextfield.setFont(f121);
		MemoryTextfield.setOpaque(true);
		MemoryTextfield.setPreferredSize(new Dimension(27,27));
		MemoryTextfield.setBorder(loweredbevel);


		panel.add(LabelOutPut, BorderLayout.NORTH);




		JPanel panel_1 = new JPanel();
		panel_1.setBorder(new EmptyBorder(0, 0, 0, 0));
		panel.add(panel_1, BorderLayout.CENTER);
		panel_1.setLayout(new BorderLayout(0, 0));


		//Add buttons to keypad panel
		// First row

		jplButtons.add(but7);
		jplButtons.add(but8);
		jplButtons.add(but9);

		// add button / and sqrt
		jplButtons.add(but13);
		jplButtons.add(but17);

		// Second row

		jplButtons.add(but4);
		jplButtons.add(but5);
		jplButtons.add(but6);

		// add button * and x^2
		jplButtons.add(but14);
		jplButtons.add(but19);

		// Third row
		jplButtons.add(but1);
		jplButtons.add(but2);
		jplButtons.add(but3);


		//adds button - and %
		jplButtons.add(but15);
		jplButtons.add(but18);

		//Fourth Row
		// add 0, +/-, ., +, and =
		jplButtons.add(but0);
		jplButtons.add(but10);
		jplButtons.add(but11);
		jplButtons.add(but16);
		jplButtons.add(but12);

		//Add jPanel jplButtons to jPanel panel_1
		panel_1.add(jplButtons, BorderLayout.CENTER);




		//jplControl is responsible for Backspace, CE, C

		jplControl = new JPanel();
		FlowLayout flowLayout = (FlowLayout) jplControl.getLayout();
		flowLayout.setAlignment(FlowLayout.RIGHT);
		jplControl.setBorder(new EmptyBorder(6, 0, 0, 0));

		//jplControl.setBackground(Color.red);

		panel_1.add(jplControl, BorderLayout.NORTH);

			//buttons inside the jplControl
		but20 = new JButton("Backspace");
		but20.setMargin(new Insets(3, 1, 3, 1));
		but20.setFont(f12);
		but20.setForeground(Color.red);
		but20.setBackground(new Color(242,243,238));
		but20.addActionListener(this);

		but21 = new JButton("CE");
		but21.setMargin(new Insets(3, 18, 3, 18));
		but21.setFont(f121);
		but21.setForeground(Color.red);
		but21.setBackground(new Color(242,243,238));
		but21.addActionListener(this);

		but22 = new JButton("C");
		but22.setMargin(new Insets(3, 21, 3, 21));
		but22.setFont(f121);
		but22.setForeground(Color.red);
		but22.setBackground(new Color(242,243,238));
		but22.addActionListener(this);

		JLabel emptySpace = new JLabel(" ");


		jplControl.add(MemoryTextfield);

		// jplControl.add(emptySpace);

		jplControl.add(emptySpace);

		jplControl.add(but20);
		jplControl.add(but21);
		jplControl.add(but22);

		//jplControl2 is responsible for MC, MR, MS, M+

		JPanel memoryPanel = new JPanel();

		memoryPanel.setBorder(new EmptyBorder(2, 0, 0, 0));

		JPanel jplControl2 = new JPanel(new GridLayout(4, 1, 7, 7));
		panel_1.add(jplControl2, BorderLayout.WEST);
		jplControl2.setBorder(new EmptyBorder(3, 0, 0, 0));

		butM1 = new JButton("MC");
		butM1.setMargin(new Insets(9, 4, 8, 4));
		butM1.setFont(f121);
		butM1.setForeground(Color.red);
		butM1.setBackground(new Color(242,243,238));
		butM1.addActionListener(this);

		butM2 = new JButton("MR");
		butM2.setMargin(new Insets(9, 4, 8, 4));
		butM2.setFont(f121);
		butM2.setForeground(Color.red);
		butM2.setBackground(new Color(242,243,238));
		butM2.addActionListener(this);

		butM3 = new JButton("MS");
		butM3.setMargin(new Insets(9, 4, 8, 4));
		butM3.setFont(f121);
		butM3.setForeground(Color.red);
		butM3.setBackground(new Color(242,243,238));
		butM3.addActionListener(this);

		butM4 = new JButton("M+");
		butM4.setMargin(new Insets(9, 4, 8, 4));
		butM4.setFont(f121);
		butM4.setForeground(Color.red);
		butM4.setBackground(new Color(242,243,238));
		butM4.addActionListener(this);

		jplControl2.add(butM1);
		jplControl2.add(butM2);
		jplControl2.add(butM3);
		jplControl2.add(butM4);




	}


	public void actionPerformed(ActionEvent e){
				double result = 0;

				if(e.getSource() == jmenuitemAbout){
					JDialog dlgAbout = new AboutDialog(this, "About Calculator", true);
					dlgAbout.setVisible(true);
				}else if(e.getSource() == jmenuitemHelp){
					JDialog dlgHelp = new HelpDialog(this, "Calculator - Help", true);
					dlgHelp.setVisible(true);
					//System.exit(0);
				}


				if(e.getSource() == but1)
				{
					addDigitToDisplay(1);
				}
				else if(e.getSource() == but2)
				{
					addDigitToDisplay(2);
				}
				else if(e.getSource() == but3)
				{
					addDigitToDisplay(3);
				}
				else if(e.getSource() == but4)
				{
					addDigitToDisplay(4);
				}
				else if(e.getSource() == but5)
				{
					addDigitToDisplay(5);
				}
				else if(e.getSource() == but6)
				{
					addDigitToDisplay(6);
				}
				else if(e.getSource() == but7)
				{
					addDigitToDisplay(7);
				}
				else if(e.getSource() == but8)
				{
					addDigitToDisplay(8);
				}
				else if(e.getSource() == but9)
				{
					addDigitToDisplay(9);
				}
				else if(e.getSource() == but0)
				{
					addDigitToDisplay(0);
				}


				// +/-
				else if(e.getSource() == but10)
				{
					processSignChange();
				}


				// decimal point
				else if(e.getSource() == but11)
				{
					addDecimalPoint();
				}


				// =
				else if(e.getSource() == but12)
				{
					processEquals();
				}



				// divide
				else if(e.getSource() == but13)
				{
					processOperator("/");

				}


				// *
				else if(e.getSource() == but14)
				{
					processOperator("*");
				}


				// -
				else if(e.getSource() == but15)
				{
					processOperator("-");
				}
				// +
				else if(e.getSource() == but16)
				{
					processOperator("+");
				}

				// sqrt
				else if(e.getSource() == but17)
				{
					if (displayMode != ERROR_MODE)
						{
							try
							{
								if (getDisplayString().indexOf("-") == 0)
									displayError("Invalid input for function!");

								result = Math.sqrt(getNumberInDisplay());
								displayResult(result);
							}

							catch(Exception ex)
							{
								displayError("Invalid input for function!");
								displayMode = ERROR_MODE;
							}
						}
				}

				// 1/x
				else if(e.getSource() == but18)
				{
						if (displayMode != ERROR_MODE){
							try
							{
								if (getNumberInDisplay() == 0)
									displayError("Cannot divide by zero!");

								result = 1 / getNumberInDisplay();
								displayResult(result);
							}

							catch(Exception ex)	{
								displayError("Cannot divide by zero!");
								displayMode = ERROR_MODE;
							}
						}
				}



				// %
				else if(e.getSource() == but19)
				{
						if (displayMode != ERROR_MODE){
							try	{
								result = getNumberInDisplay() / 100;
								displayResult(result);
							}

							catch(Exception ex)	{
								displayError("Invalid input for function!");
								displayMode = ERROR_MODE;
							}
						}

				}

				// backspace
				else if(e.getSource() == but20)
				{
						if (displayMode != ERROR_MODE){
							setDisplayString(getDisplayString().substring(0,
										getDisplayString().length() - 1));

							if (getDisplayString().length() < 1)
								setDisplayString("0");
						}

				}


				// CE
				else if(e.getSource() == but21)
				{
						clearExisting();
				}
				// C
				else if(e.getSource() == but22)
				{
						clearAll();

				}

				// MC
                else if(e.getSource() == butM1) {
                        m1 = 0;
						MemoryTextfield.setText("");
						LabelOutPut.getText();
                }

                // MR
				else if(e.getSource() == butM2) {
                        LabelOutPut.setText("");
                        LabelOutPut.setText(LabelOutPut.getText() + m1);
                		LabelOutPut.getText();
						clearOnNextDigit = true;
                }

				// MS
				else if(e.getSource() == butM3) {
						m1 = Double.parseDouble(LabelOutPut.getText());

						LabelOutPut.setText("");
						LabelOutPut.setText(LabelOutPut.getText() + m1);

						MemoryTextfield.setText("M");

						LabelOutPut.getText();
						clearOnNextDigit = true;
                }

                // M+

				else if(e.getSource() == butM4) {
                        if (k == 1) {
                                m1 = Double.parseDouble(LabelOutPut.getText());
                                k++;
                        } else {
                                m1 += Double.parseDouble(LabelOutPut.getText());
                                LabelOutPut.setText("" + m1);
                        }
                }

	}


	void setDisplayString(String s){
		LabelOutPut.setText(s);
	}

	String getDisplayString (){
		return LabelOutPut.getText();
	}

	void addDigitToDisplay(int digit){
		if (clearOnNextDigit)
			setDisplayString("");

		String inputString = getDisplayString();

		if (inputString.indexOf("0") == 0){
			inputString = inputString.substring(1);
		}

		if ((!inputString.equals("0") || digit > 0)  && inputString.length() < MAX_INPUT_LENGTH){
			setDisplayString(inputString + digit);
		}


		displayMode = INPUT_MODE;
		clearOnNextDigit = false;
	}

	void addDecimalPoint(){
		displayMode = INPUT_MODE;

		if (clearOnNextDigit)
			setDisplayString("");

		String inputString = getDisplayString();

		// If the input string already contains a decimal point, don't
		//  do anything to it.
		if (inputString.indexOf(".") < 0)
			setDisplayString(new String(inputString + "."));
	}

	void processSignChange(){
		if (displayMode == INPUT_MODE)
		{
			String input = getDisplayString();

			if (input.length() > 0 && !input.equals("0"))
			{
				if (input.indexOf("-") == 0)
					setDisplayString(input.substring(1));

				else
					setDisplayString("-" + input);
			}

		}

		else if (displayMode == RESULT_MODE)
		{
			double numberInDisplay = getNumberInDisplay();

			if (numberInDisplay != 0)
				displayResult(-numberInDisplay);
		}
	}


	void clearAll()	{
		setDisplayString("0");
		lastOperator = "0";
		lastNumber = 0;
		displayMode = INPUT_MODE;
		clearOnNextDigit = true;
	}

	void clearExisting(){
		setDisplayString("0");
		clearOnNextDigit = true;
		displayMode = INPUT_MODE;
	}



	double getNumberInDisplay()	{
		String input = LabelOutPut.getText();
		return Double.parseDouble(input);
	}

	void processOperator(String op) {
		if (displayMode != ERROR_MODE)
		{
			double numberInDisplay = getNumberInDisplay();

			if (!lastOperator.equals("0"))
			{
				try
				{
					double result = processLastOperator();
					displayResult(result);
					lastNumber = result;
				}

				catch (DivideByZeroException e)
				{
				}
			}

			else
			{
				lastNumber = numberInDisplay;
			}

			clearOnNextDigit = true;
			lastOperator = op;
		}
	}






	void displayResult(double result){
		setDisplayString(Double.toString(result));
		lastNumber = result;
		displayMode = RESULT_MODE;
		clearOnNextDigit = true;
	}



	void processEquals(){
		double result = 0;

		if (displayMode != ERROR_MODE){
			try
			{
				result = processLastOperator();
				displayResult(result);
			}

			catch (DivideByZeroException e)	{
				displayError("Cannot divide by zero!");
			}

			lastOperator = "0";
		}
	}

	double processLastOperator() throws DivideByZeroException {
		double result = 0;
		double numberInDisplay = getNumberInDisplay();

		if (lastOperator.equals("/"))
		{
			if (numberInDisplay == 0)
				throw (new DivideByZeroException());

			result = lastNumber / numberInDisplay;
		}

		if (lastOperator.equals("*"))
			result = lastNumber * numberInDisplay;

		if (lastOperator.equals("-"))
			result = lastNumber - numberInDisplay;

		if (lastOperator.equals("+"))
			result = lastNumber + numberInDisplay;

		return result;
	}


	void displayError(String errorMessage){
		setDisplayString(errorMessage);
		lastNumber = 0;
		displayMode = ERROR_MODE;
		clearOnNextDigit = true;
	}




	  public static void setNativeLookAndFeel() {
	    try {
	      UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
	    } catch(Exception e) {
	      System.out.println("Error setting native LAF: " + e);
	    }
	  }

	public static void main(String Args[]){
		Calculator calc = new Calculator();
		calc.setTitle("Calculator");
		calc.pack();
		calc.setLocation(400, 250);
		calc.setVisible(true);
		calc.setSize(270,265);
		calc.setResizable(true);
		calc.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		calc.clearAll();
		calc.setNativeLookAndFeel();

		//Add panel and Menu bar to frame

	}
}

class RoundedBorder implements Border {
        int radius;
        RoundedBorder(int radius) {
            this.radius = radius;
        }
        public Insets getBorderInsets(Component c) {
            return new Insets(this.radius+1, this.radius+1, this.radius+2, this.radius);
        }
        public boolean isBorderOpaque() {
            return true;
        }
        public void paintBorder(Component c, Graphics g, int x, int y, int width, int height) {
            g.setColor(Color.GRAY);
            g.drawRoundRect(x,y,width-1,height-1,radius,radius);
        }
	}


class DivideByZeroException extends Exception{
	public DivideByZeroException()
	{
		super();
	}

	public DivideByZeroException(String s)
	{
		super(s);
	}
}



class AboutDialog extends JDialog implements ActionListener {
	JButton jbnOk;

	Font f121 = new Font("MS Shell Dlg", 0, 12);

	AboutDialog(JFrame parent, String title, boolean modal){
		super(parent, title, modal);
		setBackground(new Color(242,243,238));

		JPanel p1 = new JPanel(new BorderLayout(0, 0));
		p1.setBorder(new EmptyBorder(0, 0, 0, 0));


		StringBuffer text = new StringBuffer();
		text.append("Java Swing Calculator\n\n");
		text.append("This calculator has been developed for a college course \nassignment and is an open source software.\n\nIts source code is licensed for copy and/or modification.\nSo feel free to adapt it to your own needs.\n\n");
		text.append("Version:              1.0\n");
		text.append("Developer:	Miguel\n");
		text.append("Contact:	miguel@procopio.co.uk\n");
		text.append("______________________________________________\n");
		text.append("Procopio Web Solutions - 0843 289 2986\n");


      	JLabel calcImg = new JLabel(new ImageIcon("6039.png"));
		calcImg.setBorder(new EmptyBorder(0, 15, 0, 0));

      	JLabel AboutImg = new JLabel(new ImageIcon("AboutIMG.png"));

		JTextArea jtAreaAbout = new JTextArea(2, 21);
		jtAreaAbout.setText(text.toString());
		jtAreaAbout.setFont(f121);

		jtAreaAbout.setEditable(false);
		jtAreaAbout.setBackground(null);
		jtAreaAbout.setBorder(new EmptyBorder(15, 15, 0, 0));

		p1.add(AboutImg, BorderLayout.NORTH);
		p1.add(calcImg, BorderLayout.WEST);
		p1.add(jtAreaAbout);

		getContentPane().add(p1, BorderLayout.CENTER);

		JPanel p2 = new JPanel(new FlowLayout(FlowLayout.CENTER));
		jbnOk = new JButton(" OK ");
		jbnOk.addActionListener(this);


		p2.add(jbnOk);
		getContentPane().add(p2, BorderLayout.SOUTH);


		setLocation(300, 200);
		setResizable(false);

		addWindowListener(new WindowAdapter() {
				public void windowClosing(WindowEvent e)
				{
					Window aboutDialogWindow = e.getWindow();
					aboutDialogWindow.dispose();
				}
			}
		);

		pack();
	}

	public void actionPerformed(ActionEvent e)
	{
		if(e.getSource() == jbnOk)	{
			this.dispose();
		}
	}

}


// Help Menu Item

class HelpDialog extends JDialog implements ActionListener {
	JButton jbnOk;

	Font f121 = new Font("MS Shell Dlg", 0, 12);

	HelpDialog(JFrame parent, String title, boolean modal){
		super(parent, title, modal);
		setBackground(new Color(242,243,238));

		JPanel p1 = new JPanel(new BorderLayout(0, 0));
		p1.setBorder(new EmptyBorder(0, 0, 0, 0));


		StringBuffer text = new StringBuffer();
		text.append("Java Swing Calculator Overview\n\n");
		text.append("You can use this calculator to perform any of the standard \noperations for which you would normally use a handheld \ncalculator. \n\nThis calculator performs basic arithmetic, such as addition, \nsubtraction, multiplication and division as well as functions. \n\nButtons definitions:\n\n");

		text.append("/    Divide                                          MC    Memory Clear\n");
		text.append("*    Multiply                                       MR    Memory Remind\n");
		text.append("-    Minus                                          MS    Memory Save\n");
		text.append("+    Addition                                      M+    Memory Add\n\n");

		text.append("sqrt = Square Root                         C       Clear\n");
		text.append("% = Percentage                               CE    Clear Existing\n");
		text.append("1/x - Reciprocal\n");

		text.append("______________________________________________\n");
		text.append("Help Line - 0843 289 2986\n");


      	JLabel calcImg = new JLabel(new ImageIcon("6039.png"));
		calcImg.setBorder(new EmptyBorder(0, 15, 0, 0));

      	JLabel AboutImg = new JLabel(new ImageIcon("AboutIMG.png"));

		JTextArea jtAreaHelp = new JTextArea(2, 21);
		jtAreaHelp.setText(text.toString());
		jtAreaHelp.setFont(f121);

		jtAreaHelp.setEditable(false);
		jtAreaHelp.setBackground(null);
		jtAreaHelp.setBorder(new EmptyBorder(15, 15, 0, 0));

		p1.add(AboutImg, BorderLayout.NORTH);
		p1.add(calcImg, BorderLayout.WEST);
		p1.add(jtAreaHelp);

		getContentPane().add(p1, BorderLayout.CENTER);

		JPanel p2 = new JPanel(new FlowLayout(FlowLayout.CENTER));
		jbnOk = new JButton(" OK ");
		jbnOk.addActionListener(this);


		p2.add(jbnOk);
		getContentPane().add(p2, BorderLayout.SOUTH);


		setLocation(300, 100);
		setResizable(false);

		addWindowListener(new WindowAdapter() {
				public void windowClosing(WindowEvent e)
				{
					Window aboutDialogWindow = e.getWindow();
					aboutDialogWindow.dispose();
				}
			}
		);

		pack();
	}

	public void actionPerformed(ActionEvent e)
	{
		if(e.getSource() == jbnOk)	{
			this.dispose();
		}
	}

}