Lolz

package engineupgrade;

/**
 *
 * @author s1100117
 */
import java.util.Random;
import java.awt.*;
import javax.swing.*;
import java.awt.event.*;

public class Main extends JFrame{

        private JPanel paBase = new JPanel(new GridLayout(3,1,5,5));
        private JPanel paUpper = new JPanel(new GridLayout(2,2,5,5));
        private JPanel paMiddle = new JPanel(new FlowLayout(FlowLayout.CENTER));
        private JPanel paLower = new JPanel(new GridLayout(4,1,0,5));

    private JTextField tfPower = new JTextField(2);
    private JTextField tfUpgradeP = new JTextField(2);
        private JTextField tfWeight = new JTextField(2);
    private JTextField tfUpgradeW = new JTextField(2);

    private JLabel lbPower = new JLabel("Current power");
    private JLabel lbUpgradeP = new JLabel("Desired power upgrade");
        private JLabel lbWeight = new JLabel("Current weight");
    private JLabel lbUpgradeW = new JLabel("Desired weight upgrade");
    private JLabel lbResult = new JLabel("");

    private JButton btResultP = new JButton("Upgrade power");
        private JButton btResultW = new JButton("Upgrade weight");
    private JButton btQuit = new JButton("Quit");
    private JButton btEmpty = new JButton("Empty fields");

    public Main()
    {
        this.setTitle("Engine upgrade counter");
        this.setSize(640, 320);
        this.setLocation(400, 400);
        this.setComponents();
        this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    }

    private void setComponents()
    {
        paUpper.add(lbPower);
                paUpper.add(tfPower);
                paUpper.add(lbUpgradeP);
                paUpper.add(tfUpgradeP);
                paUpper.add(lbWeight);
                paUpper.add(tfWeight);
                paUpper.add(lbUpgradeW);
                paUpper.add(tfUpgradeW);
                paMiddle.add(lbResult);
        paLower.add(btResultP);
                paLower.add(btResultW);
        paLower.add(btEmpty);
                paLower.add(btQuit);
                paBase.add(paUpper);
                paBase.add(paMiddle);
                paBase.add(paLower);

            this.add(paBase);

            btQuit.addActionListener(new AlsQuit());
            btEmpty.addActionListener(new AlsEmpty());
            btResultP.addActionListener(new AlsResultPower());
            btResultW.addActionListener(new AlsResultWeight());
    }

        class AlsQuit implements ActionListener{
            public void actionPerformed(ActionEvent e){
                System.exit(0);
            }
        }
        class AlsEmpty implements ActionListener{
            public void actionPerformed(ActionEvent e){
                tfPower.setText("");
                tfUpgradeP.setText("");
                tfWeight.setText("");
                tfUpgradeW.setText("");
            }
        }
        class AlsResultPower implements ActionListener{
            public void actionPerformed(ActionEvent e){
                try{
                String CurrentHPT = tfPower.getText();
                String UpgradeAmountT = tfUpgradeP.getText();
                int CurrentHP = Integer.parseInt(CurrentHPT)-640;
                int UpgradeAmountP = Integer.parseInt(UpgradeAmountT);
                Random randomchance = new Random();
                int r = randomchance.nextInt(140);
                UpgradeChanceP(CurrentHP, UpgradeAmountP, r);
                }
                catch(Exception error){
                    lbResult.setText("Input error: "+error);
                }
            }
        }
        class AlsResultWeight implements ActionListener{
            public void actionPerformed(ActionEvent e){
                try{
                String CurrentWT = tfWeight.getText();
                String UpgradeAmountWT = tfUpgradeW.getText();
                int CurrentW = Integer.parseInt(CurrentWT)-50;
                int UpgradeAmountW = Integer.parseInt(UpgradeAmountWT);
                Random randomchance = new Random();
                int r = randomchance.nextInt(120);
                UpgradeChanceW(CurrentW, UpgradeAmountW, r);
                }
                catch(Exception error){
                    lbResult.setText("Input error: "+error);
                }
            }
        }
    public static void main(String[] args)
    {
        SwingUtilities.invokeLater(new Runnable() {
      public void run() {
        new Main().setVisible(true);
      }
    });

    }

  private void UpgradeChanceP(int CurrentHP, int UpgradeAmountP, int r){
      int result;
      result = (125-CurrentHP-UpgradeAmountP-r);
      if (result > 20){
          lbResult.setText("Engine successfully upgraded by 20 horsepower.");
      }
      else if(result > 0)
      {
          lbResult.setText("Engine successfully upgraded by " +result+ " horsepower.");
      }
      else{
          lbResult.setText("Engine upgrade failed.");
      }
 }
    private void UpgradeChanceW(int CurrentW, int UpgradeAmountW, int r){
      int result;
      result = (CurrentW-UpgradeAmountW-r);
      if (result > 10){
          lbResult.setText("Engine successfully lightened by 10 kilograms.");
      }
      else if(result > 0)
        {
          lbResult.setText("Engine successfully lightened by " +result+ " kilograms.");
      }
      else{
          lbResult.setText("Engine upgrade failed.");
      }
 }
}