Notepad.java

/**
 * Class utama dari aplikasi Notepad
 *
 * @author Andika Nugrahanto
 * @version 28/12/2020
 */

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.util.Scanner;
import java.io.*;

public class Notepad extends JFrame implements ActionListener {
  private TextArea textArea = new TextArea("", 0,0, TextArea.SCROLLBARS_VERTICAL_ONLY);
  private MenuBar menuBar = new MenuBar(); // Membuat MenuBar
    private Menu file = new Menu(); // Membuat menu File

    private MenuItem newFile = new MenuItem(); // Opsi New
    private MenuItem openFile = new MenuItem();  // Opsi Open
    private MenuItem saveFile = new MenuItem(); // Opsi Save
    private MenuItem close = new MenuItem(); // Opsi Close

    public Notepad() {
        this.setSize(1280, 720); // Set ukuran Notepad
        this.setTitle("Java Notepad"); // Set Nama aplikasi
        setDefaultCloseOperation(EXIT_ON_CLOSE); // Set operasi penutupan aplikasi
        this.textArea.setFont(new Font("Century Gothic", Font.BOLD, 12)); // Set font default di TextArea

        this.getContentPane().setLayout(new BorderLayout());
        this.getContentPane().add(textArea);

        // Menambah menu bar ke GUI
        this.setMenuBar(this.menuBar);
        this.menuBar.add(this.file);

        this.file.setLabel("File");

        //Opsi New
        this.newFile.setLabel("New"); //label opsi
        this.newFile.addActionListener(this); //action listener supaya tahu ketika diklik
        this.newFile.setShortcut(new MenuShortcut(KeyEvent.VK_N, false)); // Shortcut ctrl + n
        this.file.add(this.newFile); // menambahkan ke menu "File"

        //Opsi Open
        this.openFile.setLabel("Open");
        this.openFile.addActionListener(this);
        this.openFile.setShortcut(new MenuShortcut(KeyEvent.VK_O, false)); // Shortcut ctrl + o
        this.file.add(this.openFile);

        //Opsi Save
        this.saveFile.setLabel("Save");
        this.saveFile.addActionListener(this);
        this.saveFile.setShortcut(new MenuShortcut(KeyEvent.VK_S, false)); // Shortcut ctrl + s
        this.file.add(this.saveFile);

        //Opsi Close
        this.close.setLabel("Close");
        this.close.setShortcut(new MenuShortcut(KeyEvent.VK_F4, false)); // Shortcut ctrl + F4
        this.close.addActionListener(this);
        this.file.add(this.close);
    }

    public void actionPerformed (ActionEvent e) {
        // Jika memilih Opsi Close
        if (e.getSource() == this.close)
            this.dispose(); // Dispose semua resource dan tutup aplikasi

        // Jika memilih opsi Open
        else if (e.getSource() == this.openFile) {
            JFileChooser open = new JFileChooser(); // Membuka file chooser
            int option = open.showOpenDialog(this); // Untuk mendapatkan opsi yang dipilih user (approve atau cancel)

            // Jika user klik OK, terdapat "APPROVE_OPTION"
            if (option == JFileChooser.APPROVE_OPTION) {
                this.textArea.setText(""); // Clear TextArea kemudian membuka isi File
                try {
                    // Membuat Scanner untuk membaca File
                    Scanner scan = new Scanner(new FileReader(open.getSelectedFile().getPath()));
                    while (scan.hasNext())
                        this.textArea.append(scan.nextLine() + "\n");
                } catch (Exception ex) {
                    System.out.println(ex.getMessage());
                }
            }
        }

        // Jika memilih opsi Save
        else if (e.getSource() == this.saveFile) {
            JFileChooser save = new JFileChooser(); // Membuka File Chooser
            int option = save.showSaveDialog(this);

            if (option == JFileChooser.APPROVE_OPTION) {
                try {

                    BufferedWriter out = new BufferedWriter(new FileWriter(save.getSelectedFile().getPath()));
                    out.write(this.textArea.getText());
                    out.close();
                } catch (Exception ex) {
                    System.out.println(ex.getMessage());
                }
            }
        }

        // Jika memilih opsi New
        else if (e.getSource() == this.newFile) {
            textArea.setText("");
        }
    }


    public static void main(String args[]) {
        Notepad app = new Notepad();
        app.setVisible(true);


}
}