ReeferGUI

import java.awt.EventQueue;
import java.awt.Font;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.text.DecimalFormat;
import java.util.ArrayList;

import javax.swing.GroupLayout;
import javax.swing.GroupLayout.Alignment;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.LayoutStyle.ComponentPlacement;
import javax.swing.Timer;
import javax.swing.border.EmptyBorder;

public class ReeferGUI extends JFrame
{
    private static final long serialVersionUID = 1L;

    private JPanel contentPane;

    private JLabel lblPercent1 = new JLabel("%");;
    private JLabel labelPercent2 = new JLabel("%");;

    private JLabel lblWeedAmtG = new JLabel("Weed Amount (g)");
    private JLabel labelDabAmtG = new JLabel("Dab Amount (g)");
    private JLabel lblWeedAmtO = new JLabel("Weed Amount (O)");
    private JLabel lblDabAmtO = new JLabel("Dab Amount (O)");
    private JLabel lblWeedPotency = new JLabel("THC Potency (Weed)");
    private JLabel lblDabPotency = new JLabel("THC Potency (Dabs)");

    private JTextField weedAmtG,      // 0
                             dabAmtG,        // 1
                             weedAmtO,       // 2       These are the index's of each of the TextFields in
                             dabAmtO,       // 3       textFieldList in the TimerListener class.
                             weedPotency,   // 4
                             dabPotency;    // 5

    public ReeferGUI()
    {
        setTitle("Reefer");
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setBounds(100, 100, 219, 272);
        contentPane = new JPanel();
        contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
        setContentPane(contentPane);

        weedAmtG = new JTextField();
        weedAmtG.setColumns(10);
        TextFieldListener weedAmtGListener = new TextFieldListener(weedAmtG, true);
        weedAmtG.addKeyListener(weedAmtGListener);
        weedAmtG.addMouseListener(weedAmtGListener);

        dabAmtG = new JTextField();
        dabAmtG.setColumns(10);
        TextFieldListener dabAmtGListener = new TextFieldListener(dabAmtG, true);
        dabAmtG.addKeyListener(dabAmtGListener);
        dabAmtG.addMouseListener(dabAmtGListener);

        weedAmtO = new JTextField();
        weedAmtO.setColumns(10);
        TextFieldListener weedAmtOListener = new TextFieldListener(weedAmtO, true);
        weedAmtO.addKeyListener(weedAmtOListener);
        weedAmtO.addMouseListener(weedAmtOListener);

        dabAmtO = new JTextField();
        dabAmtO.setColumns(10);
        TextFieldListener dabAmtOListener = new TextFieldListener(dabAmtO, true);
        dabAmtO.addKeyListener(dabAmtOListener);
        dabAmtO.addMouseListener(dabAmtOListener);

        weedPotency = new JTextField();
        weedPotency.setColumns(10);
        TextFieldListener weedPotencyListener = new TextFieldListener(weedPotency, false);
        weedPotency.addKeyListener(weedPotencyListener);
        weedPotency.addMouseListener(weedPotencyListener);
        weedPotency.setHorizontalAlignment(JTextField.RIGHT);
        weedPotency.setText("17");

        dabPotency = new JTextField();
        dabPotency.setColumns(10);
        TextFieldListener dabPotencyListener = new TextFieldListener(dabPotency, false);
        dabPotency.addKeyListener(dabPotencyListener);
        dabPotency.addMouseListener(dabPotencyListener);
        dabPotency.setHorizontalAlignment(JTextField.RIGHT);
        dabPotency.setText("85");

        lblPercent1.setFont(new Font("Tahoma", Font.PLAIN, 12));
        labelPercent2.setFont(new Font("Tahoma", Font.PLAIN, 12));

        initializeComponentLayout();
    }

    private void initializeComponentLayout()
    {
        GroupLayout gl_contentPane = new GroupLayout(contentPane);
        gl_contentPane.setHorizontalGroup(
            gl_contentPane.createParallelGroup(Alignment.LEADING)
                .addGroup(gl_contentPane.createSequentialGroup()
                    .addGroup(gl_contentPane.createParallelGroup(Alignment.LEADING)
                        .addGroup(gl_contentPane.createSequentialGroup()
                            .addGroup(gl_contentPane.createParallelGroup(Alignment.TRAILING, false)
                                .addComponent(lblWeedAmtG)
                                .addComponent(weedAmtG, Alignment.LEADING)
                                .addComponent(lblWeedAmtO, Alignment.LEADING, GroupLayout.DEFAULT_SIZE, GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
                            .addGap(18)
                            .addGroup(gl_contentPane.createParallelGroup(Alignment.LEADING)
                                .addComponent(lblDabAmtO, GroupLayout.PREFERRED_SIZE, 87, GroupLayout.PREFERRED_SIZE)
                                .addGroup(gl_contentPane.createSequentialGroup()
                                    .addGap(1)
                                    .addComponent(labelDabAmtG, GroupLayout.PREFERRED_SIZE, 85, GroupLayout.PREFERRED_SIZE))
                                .addComponent(dabAmtG, GroupLayout.PREFERRED_SIZE, GroupLayout.DEFAULT_SIZE, GroupLayout.PREFERRED_SIZE)))
                        .addGroup(gl_contentPane.createSequentialGroup()
                            .addComponent(weedAmtO, GroupLayout.PREFERRED_SIZE, 87, GroupLayout.PREFERRED_SIZE)
                            .addGap(18)
                            .addComponent(dabAmtO, GroupLayout.PREFERRED_SIZE, 87, GroupLayout.PREFERRED_SIZE))
                        .addGroup(gl_contentPane.createSequentialGroup()
                            .addGap(68)
                            .addComponent(weedPotency, GroupLayout.PREFERRED_SIZE, 33, GroupLayout.PREFERRED_SIZE)
                            .addPreferredGap(ComponentPlacement.RELATED)
                            .addComponent(lblPercent1))
                        .addGroup(gl_contentPane.createSequentialGroup()
                            .addGap(44)
                            .addGroup(gl_contentPane.createParallelGroup(Alignment.LEADING)
                                .addComponent(lblDabPotency, GroupLayout.PREFERRED_SIZE, 101, GroupLayout.PREFERRED_SIZE)
                                .addComponent(lblWeedPotency)))
                        .addGroup(gl_contentPane.createSequentialGroup()
                            .addGap(67)
                            .addComponent(dabPotency, GroupLayout.PREFERRED_SIZE, 33, GroupLayout.PREFERRED_SIZE)
                            .addPreferredGap(ComponentPlacement.RELATED)
                            .addComponent(labelPercent2, GroupLayout.PREFERRED_SIZE, 12, GroupLayout.PREFERRED_SIZE)))
                    .addContainerGap(GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
        );
        gl_contentPane.setVerticalGroup(
            gl_contentPane.createParallelGroup(Alignment.LEADING)
                .addGroup(gl_contentPane.createSequentialGroup()
                    .addGroup(gl_contentPane.createParallelGroup(Alignment.LEADING)
                        .addGroup(gl_contentPane.createSequentialGroup()
                            .addComponent(lblWeedAmtG, GroupLayout.PREFERRED_SIZE, 16, GroupLayout.PREFERRED_SIZE)
                            .addPreferredGap(ComponentPlacement.RELATED)
                            .addComponent(weedAmtG, GroupLayout.PREFERRED_SIZE, GroupLayout.DEFAULT_SIZE, GroupLayout.PREFERRED_SIZE))
                        .addGroup(gl_contentPane.createSequentialGroup()
                            .addComponent(labelDabAmtG, GroupLayout.PREFERRED_SIZE, 16, GroupLayout.PREFERRED_SIZE)
                            .addGap(6)
                            .addComponent(dabAmtG, GroupLayout.PREFERRED_SIZE, GroupLayout.DEFAULT_SIZE, GroupLayout.PREFERRED_SIZE)))
                    .addPreferredGap(ComponentPlacement.RELATED)
                    .addGroup(gl_contentPane.createParallelGroup(Alignment.BASELINE)
                        .addComponent(lblWeedAmtO)
                        .addComponent(lblDabAmtO))
                    .addPreferredGap(ComponentPlacement.RELATED)
                    .addGroup(gl_contentPane.createParallelGroup(Alignment.BASELINE)
                        .addComponent(weedAmtO, GroupLayout.PREFERRED_SIZE, GroupLayout.DEFAULT_SIZE, GroupLayout.PREFERRED_SIZE)
                        .addComponent(dabAmtO, GroupLayout.PREFERRED_SIZE, GroupLayout.DEFAULT_SIZE, GroupLayout.PREFERRED_SIZE))
                    .addGap(25)
                    .addComponent(lblWeedPotency)
                    .addPreferredGap(ComponentPlacement.RELATED)
                    .addGroup(gl_contentPane.createParallelGroup(Alignment.BASELINE)
                        .addComponent(lblPercent1, GroupLayout.PREFERRED_SIZE, 20, GroupLayout.PREFERRED_SIZE)
                        .addComponent(weedPotency, GroupLayout.PREFERRED_SIZE, GroupLayout.DEFAULT_SIZE, GroupLayout.PREFERRED_SIZE))
                    .addPreferredGap(ComponentPlacement.UNRELATED)
                    .addComponent(lblDabPotency)
                    .addPreferredGap(ComponentPlacement.RELATED)
                    .addGroup(gl_contentPane.createParallelGroup(Alignment.BASELINE)
                        .addComponent(dabPotency, GroupLayout.PREFERRED_SIZE, GroupLayout.DEFAULT_SIZE, GroupLayout.PREFERRED_SIZE)
                        .addComponent(labelPercent2, GroupLayout.PREFERRED_SIZE, 20, GroupLayout.PREFERRED_SIZE))
                    .addContainerGap(46, Short.MAX_VALUE))
        );
        contentPane.setLayout(gl_contentPane);
    }

    public static void openNewGUI()
    {
        EventQueue.invokeLater(new Runnable()
        {
            public void run()
            {
                try
                {
                    ReeferGUI frame = new ReeferGUI();
                    frame.setVisible(true);
                }
                catch (Exception e)
                {
                    e.printStackTrace();
                }
            }
        });
    }
}
class TextFieldListener implements KeyListener, MouseListener
{
    private static ArrayList<JTextField> connectedFieldList = new ArrayList<>();
    private static ArrayList<JTextField> textFieldList = new ArrayList<>();

    private static JTextField currentlyEditingField;
    private static JTextField lastEditedConnectedField;

    private JTextField textField;

    static boolean firstRun = true;

    private static Timer timer = new Timer(500, new TimerListener());

    static
    {
        timer.start();
    }

    public TextFieldListener(JTextField field, boolean addToList)
    {
        textField = field;
        textFieldList.add(field);

        if (addToList)
        {
            if (firstRun) // Set the top left box (first one added to list) to the currently editing box
            {
                firstRun = false;
                currentlyEditingField = textField;
            }
            else  // Set all text boxes to "--" besides the top left one
            {
                field.setText("--");

            }

            field.setHorizontalAlignment(JTextField.CENTER);
            connectedFieldList.add(field);
        }
    }

    @Override
    public void keyPressed(KeyEvent e) { }

    private void clearConnectedTextFields()
    {
        for (JTextField f : connectedFieldList)
        {
            if (f != null && !(f.equals(textField)))
            {
                f.setText("--");
            }
        }

    }

    @Override
    public void keyReleased(KeyEvent arg0) { }

    @Override
    public void keyTyped(KeyEvent e)
    {
        currentlyEditingField = textField;

        if (connectedFieldList.contains(textField))
        {
            lastEditedConnectedField = textField;
            clearConnectedTextFields();
        }
    }

    @Override
    public void mouseClicked(MouseEvent e)
    {
        textField.setText("");
        currentlyEditingField = textField;

        if (connectedFieldList.contains(textField))
        {
            lastEditedConnectedField = textField;
            clearConnectedTextFields();
        }
    }

    @Override
    public void mouseEntered(MouseEvent e) { }

    @Override
    public void mouseExited(MouseEvent e) { }

    @Override
    public void mousePressed(MouseEvent e)  { }

    @Override
    public void mouseReleased(MouseEvent e) { }


    static class TimerListener implements ActionListener
    {
        @Override
        public void actionPerformed(ActionEvent e)
        {
            ping();
        }

        private void ping()
        {
            if (areAllFieldsValid()) // If all fields are valid numbers, perform calculations
            {
                int index = 0; // Figure out the index of the last edited text box because the calculations are based off of this index
                for (int i = 0; i < connectedFieldList.size(); i++)
                {
                    if (connectedFieldList.get(i).equals(lastEditedConnectedField))
                    {
                        index = i;
                    }
                }

                JTextField f = connectedFieldList.get(index);

                double weedPotency = Double.parseDouble(textFieldList.get(4).getText());
                double dabPotency = Double.parseDouble(textFieldList.get(5).getText());
                double weedToDabRatio = weedPotency / dabPotency;
                double dabToWeedRatio = dabPotency / weedPotency;

                DecimalFormat df = new DecimalFormat("#.##");

                double weedG = 0, dabG = 0, weedO = 0, dabO = 0;

                switch (index)
                {
                case 0: // CONDITION they edited the Weed Amount (g) field, so other values should be based off of this field
                    weedG = Double.parseDouble(f.getText());
                    weedO = weedG / 28.0;
                    dabG = weedToDabRatio * weedG;
                    dabO = weedToDabRatio * weedO;
                    break;
                case 1: // CONDITION they edited the Dab Amount (g) field, so other values should be based off of this field
                    dabG = Double.parseDouble(f.getText());
                    dabO = dabG / 28.0;
                    weedG = dabToWeedRatio * dabG;
                    weedO = weedG / 28.0;
                    break;
                case 2: // CONDITION they edited the Weed Amount (O) field, so other values should be based off of this field
                    weedO = Double.parseDouble(f.getText());
                    weedG = weedO * 28.0;
                    dabG = weedToDabRatio * weedG;
                    dabO = weedToDabRatio * weedO;
                    break;
                case 3: // CONDITION they edited the Dab Amount (O) field, so other values should be based off of this field
                    dabO = Double.parseDouble(f.getText());
                    dabG = dabG * 28.0;
                    weedG = dabToWeedRatio * dabG;
                    weedO = weedG / 28.0;
                    break;
                }

                connectedFieldList.get(0).setText(df.format(weedG));
                connectedFieldList.get(1).setText(df.format(dabG));
                connectedFieldList.get(2).setText(df.format(weedO));
                connectedFieldList.get(3).setText(df.format(dabO));
            }

        }

        private boolean areAllFieldsValid()
        {
            boolean valid = true;
            int numBlankFields = 0;
            for (JTextField f : textFieldList)
            {
                try
                {
                    Double.parseDouble(f.getText());
                }
                catch (Exception e)
                {
                    if (!(f.getText().equals("--")))
                    {
                        valid = false;

                        if (!(f.equals(currentlyEditingField))) // Don't change the text to #NAN if the user is currently editing it
                        {
                            f.setText("#NAN");
                        }
                    }
                    else
                    {
                        numBlankFields++;
                    }
                }
            }

            if (numBlankFields > 3) // If all 4 fields are blank it can't be valid
            {
                valid = false;
            }
            return valid;
        }

    }
}