/**

* This class contains all the code to make up the GUI for the postfix expression calculator

* @author Jonny Pine

* @version 1.0

*/

import javax.swing.*;

import javax.swing.JTextField;

import javax.swing.JLabel;

import javax.swing.SwingConstants;

import javax.swing.border.EmptyBorder;

import java.awt.GridBagLayout;

import java.awt.GridBagConstraints;

import java.awt.Insets;

import java.awt.event.*;

import java.awt.*;

public class projTwoFrame extends JFrame {

private JPanel contentPane;

private JTextField textFieldInput;

private JTextField textFieldOutput;

private Postfix evaluate;

/**

* Create the frame.

*/

public projTwoFrame() {

evaluate = new Postfix();

/**setting up the layout of the content pane**/

setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

setBounds(100, 100, 495, 114);

contentPane = new JPanel();

contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));

setContentPane(contentPane);

GridBagLayout gbl_contentPane = new GridBagLayout();

gbl_contentPane.columnWidths = new int[]{88, 86, 41, 39, 30, 86, 0};

gbl_contentPane.rowHeights = new int[]{22, 0, 0};

gbl_contentPane.columnWeights = new double[]{0.0, 0.0, 0.0, 0.0, 0.0, 0.0, Double.MIN_VALUE};

gbl_contentPane.rowWeights = new double[]{0.0, 0.0, Double.MIN_VALUE};

contentPane.setLayout(gbl_contentPane);

/**this sets up the label "postfix expression"**/

JLabel lblPostfixExpression = new JLabel("Postfix Expression");

lblPostfixExpression.setHorizontalAlignment(SwingConstants.CENTER);

GridBagConstraints gbc_lblPostfixExpression = new GridBagConstraints();

gbc_lblPostfixExpression.anchor = GridBagConstraints.WEST;

gbc_lblPostfixExpression.insets = new Insets(0, 0, 5, 5);

gbc_lblPostfixExpression.gridx = 0;

gbc_lblPostfixExpression.gridy = 0;

contentPane.add(lblPostfixExpression, gbc_lblPostfixExpression);

/**this input field**/

textFieldInput = new JTextField();

GridBagConstraints gbc_textFieldInput = new GridBagConstraints();

gbc_textFieldInput.anchor = GridBagConstraints.WEST;

gbc_textFieldInput.insets = new Insets(0, 0, 5, 5);

gbc_textFieldInput.gridx = 1;

gbc_textFieldInput.gridy = 0;

textFieldInput.addKeyListener(new KeyListener(){

/**this method associated with this key listener clears the text in the output box**/

public void keyPressed(KeyEvent arg0) {

textFieldOutput.setText("");

}

public void keyReleased(KeyEvent arg0) {

// required method

}

public void keyTyped(KeyEvent arg0) {

// required method

}

});

contentPane.add(textFieldInput, gbc_textFieldInput);

textFieldInput.setColumns(10);

Button button_1 = new Button("Solve");

button_1.addActionListener(new ActionListener(){

/**this method preforms the action event associated with this button**/

public void actionPerformed(ActionEvent e) {

try{

String expr = (textFieldInput.getText());

textFieldOutput.setText(String.valueOf(evaluate.evaluate(expr)));

}

catch (NumberFormatException nfe){

JOptionPane.showMessageDialog(null, "Your input is incorrectly typed");

}

}

});

GridBagConstraints gbc_button_1 = new GridBagConstraints();

gbc_button_1.anchor = GridBagConstraints.NORTHWEST;

gbc_button_1.insets = new Insets(0, 0, 5, 5);

gbc_button_1.gridx = 2;

gbc_button_1.gridy = 0;

contentPane.add(button_1, gbc_button_1);

/**creates a jlabel with the word result**/

JLabel lblResult = new JLabel("Result");

lblResult.setHorizontalAlignment(SwingConstants.CENTER);

GridBagConstraints gbc_lblResult = new GridBagConstraints();

gbc_lblResult.anchor = GridBagConstraints.WEST;

gbc_lblResult.insets = new Insets(0, 0, 0, 5);

gbc_lblResult.gridx = 0;

gbc_lblResult.gridy = 1;

contentPane.add(lblResult, gbc_lblResult);

textFieldOutput = new JTextField();

/**this defines the output field**/

GridBagConstraints gbc_textFieldOutput = new GridBagConstraints();

gbc_textFieldOutput.insets = new Insets(0, 0, 0, 5);

gbc_textFieldOutput.anchor = GridBagConstraints.WEST;

gbc_textFieldOutput.gridx = 1;

gbc_textFieldOutput.gridy = 1;

textFieldOutput.setEditable(false);

contentPane.add(textFieldOutput, gbc_textFieldOutput);

textFieldOutput.setColumns(10);

/**this adds an action listened to the button**/

Button button = new Button("Clear");

button.addActionListener(new ActionListener(){

public void actionPerformed(ActionEvent arg0) {

textFieldInput.setText("");

textFieldOutput.setText("");

}

});

/**this specifications for the clear button**/

GridBagConstraints gbc_button = new GridBagConstraints();

gbc_button.anchor = GridBagConstraints.NORTHWEST;

gbc_button.insets = new Insets(0, 0, 0, 5);

gbc_button.gridx = 2;

gbc_button.gridy = 1;

contentPane.add(button, gbc_button);

}

/**

* The method for actually running the class and setting the visibility to true

**/

public void run() {

projTwoFrame frame = new projTwoFrame();

try {

frame.setVisible(true);

} catch (Exception e) {

e.printStackTrace();

}

}

}