import javax.swing.*;
import java.awt.*;
import java.awt.event.*;

public class Assignment3 extends JApplet implements ActionListener {
    JTextField T1 ;
    JTextField T2 ;
    JLabel invalid;
    JTextArea result;
    JButton exit ;
    JLabel L1;
    JLabel name;
    JLabel gpa;
    JButton save;
    JButton clear;
    int max=0;
    double [] gArray;
    String [] nArray;

        public void init() {
        Container cp = getContentPane();
        cp.setLayout(new FlowLayout());
        L1 = new JLabel("Enter studens name and GPA:  ");
        cp.add(L1);
        name = new JLabel("Name: ",SwingConstants.LEFT);
        T1 = new JTextField(SwingConstants.RIGHT);
        T1.setColumns(30);
        cp.add(name);
        cp.add(T1);
        gpa = new JLabel("GPA: ",SwingConstants.LEFT);
        cp.add(gpa);
        T2 = new JTextField(SwingConstants.RIGHT);
        T2.setColumns(20);
        cp.add(T2);
        result = new JTextArea(5,30);
        cp.add(result);
        result.setVisible(false);
        save = new JButton("Save");
        cp.add(save);
        clear = new JButton("Clear");
        cp.add(clear);
        exit = new JButton("Exit");
        cp.add(exit);
        invalid = new JLabel("Invalid GPA!");
        cp.add(invalid);
        invalid.setForeground(Color.RED);
        invalid.setVisible(false);
        save.addActionListener(this);
        clear.addActionListener(this);
        exit.addActionListener(this);
        nArray = new String [100];
        gArray = new double[100];
    }

    public void actionPerformed(ActionEvent e) {
        String ac  = e.getActionCommand();
        if(ac.equals("Save")){
            Double g = Double.valueOf(T2.getText());
            if(g<0||g>4)
                invalid.setVisible(true);
            else{
                nArray[i]=T1.getText();
                gArray[i]=g;
                i++;
                T1.setText("");
                T2.setText("");
            }
        }
        if(ac.equals("Clear")){
            T1.setText("");
            T2.setText("");
            invalid.setVisible(false);
        }
        //Exit button
        if(ac.equals("Exit")){
            result.setVisible(true);
            save.setVisible(false);
            clear.setVisible(false);
            exit.setVisible(false);
            T1.setVisible(false);
            T2.setVisible(false);
            L1.setVisible(false);
            name.setVisible(false);
            gpa.setVisible(false);
            for(int j=0;j<i;j++){
                if(gArray[j]>gArray[max]) {
                    max=j;
                }//if end
            }// for loop end
            String s=(nArray[max]+" Scored the maximum GPA ("+gArray[max]+") n among total of " +i+" students.");
            result.setText(s);
        }//first if end
    }// end of method
}// end of class