gistfile1.java

/*
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 * and open the template in the editor.
 */
package futurevalueapp;

import java.awt.BorderLayout;
import java.awt.FlowLayout;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Insets;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.text.NumberFormat;
import javax.swing.JButton;
import javax.swing.JComboBox;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextField;

/**
 *
 * @author SeeD419
 */
public class FutureValuePanel extends JPanel implements ActionListener {
    private JTextField  paymentTextField,
                        rateTextField,
                        yearsTextField,
                        futureValueTextField;
    private JLabel      paymentLabel,
                        rateLabel,
                        yearsLabel,
                        futureValueLabel;
    private JButton     calculateButton,
                        exitButton;
    private JComboBox   yearsComboBox;

    public FutureValuePanel()
    {
        // display panel
        JPanel displayPanel = new JPanel();
        displayPanel.setLayout(new GridBagLayout());

        // payment label
        paymentLabel = new JLabel("Monthly Payment:");
        displayPanel.add(paymentLabel, getConstraints(0, 0, 1, 1, GridBagConstraints.WEST));

        // payment text field
        paymentTextField = new JTextField(10);
        displayPanel.add(paymentTextField, getConstraints(0, 1, 1, 1, GridBagConstraints.EAST));

        // rate label
        rateLabel = new JLabel("Yearly Interest Rate:");
        displayPanel.add(rateLabel, getConstraints(1, 0, 1, 1, GridBagConstraints.WEST));

        // rate text field
        rateTextField = new JTextField(10);
        displayPanel.add(rateTextField, getConstraints(1, 1, 1, 1, GridBagConstraints.EAST));

        // years label
        yearsLabel = new JLabel("Number of Years:");
        displayPanel.add(yearsLabel, getConstraints(2, 0, 1, 1, GridBagConstraints.WEST));

        // years text field
        //yearsTextField = new JTextField(10);
        //displayPanel.add(yearsTextField);
        Integer years[] = {1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20};
        yearsComboBox = new JComboBox(years);
        displayPanel.add(yearsComboBox, getConstraints(2, 1, 1, 1, GridBagConstraints.EAST));

        // future value label
        futureValueLabel = new JLabel("Future Value:");
        displayPanel.add(futureValueLabel, getConstraints(3, 0, 1, 1, GridBagConstraints.WEST));

        // future value text field
        futureValueTextField = new JTextField(10);
        futureValueTextField.setEditable(false);
        futureValueTextField.setFocusable(false);
        displayPanel.add(futureValueTextField, getConstraints(3, 1, 1, 1, GridBagConstraints.EAST));

        // button panel
        JPanel buttonPanel = new JPanel();
        buttonPanel.setLayout(new GridBagLayout());

        // calculate button
        calculateButton = new JButton("Calculate");
        calculateButton.addActionListener(this);
        buttonPanel.add(calculateButton, getConstraints(4, 0, 1, 1, GridBagConstraints.WEST));

        // exit button
        exitButton = new JButton("Exit");
        exitButton.addActionListener(this);
        buttonPanel.add(exitButton, getConstraints(4, 1, 1, 1, GridBagConstraints.EAST));

        // add panels to main panel
        this.setLayout(new BorderLayout());
        this.add(displayPanel, BorderLayout.CENTER);
        this.add(buttonPanel, BorderLayout.SOUTH);
    }

    @Override
    public void actionPerformed(ActionEvent e)
    {
        Object source = e.getSource();
        if (source == exitButton)
            System.exit(0);
        else if (source == calculateButton)
        {
            double payment = Double.parseDouble(paymentTextField.getText());
            double rate = Double.parseDouble(rateTextField.getText());
            int years = Integer.parseInt(yearsTextField.getText());
            double futureValue = FinancialCalculations.calculateFutureValue(
                payment, rate, years);
            NumberFormat currency = NumberFormat.getCurrencyInstance();
            futureValueTextField.setText(currency.format(futureValue));
        }
    }
    
    private GridBagConstraints getConstraints(int gridx, int gridy, int gridwidth, int gridheight, int anchor){
        GridBagConstraints c = new GridBagConstraints();
        c.insets = new Insets(5,5,5,5);
        c.ipadx = 0;
        c.ipady = 0;
        c.gridx = gridy;
        c.gridy = gridx;
        c.gridwidth = gridwidth;
        c.gridheight = gridheight;
        c.anchor = anchor;
        return c;
    }
}