user_interface.java

import java.awt.Font;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.io.File;
import java.io.IOException;
import java.net.Inet4Address;
import java.net.InetAddress;
import java.net.NetworkInterface;
import javax.swing.DefaultListModel;
import javax.swing.JButton;
import javax.swing.JFileChooser;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JList;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;
import javax.swing.JOptionPane;
import javax.swing.JScrollPane;
import javax.swing.JTextField;
import javax.swing.event.ListSelectionEvent;
import javax.swing.event.ListSelectionListener;
import java.util.ArrayList;
import java.util.Enumeration;
import java.util.List;

public class user_interface extends JFrame {
    public static String address;
    private static List<String> addresses = new ArrayList<>();
    private boolean is_connected = false;
    private packet_operations peer = new packet_operations(this);

    // Define bar and its elements.
    private JMenuBar bar = new JMenuBar();
    private JMenu files_menu = new JMenu("Files");
    private JMenu help_menu = new JMenu("Help");
    private JMenuItem connect_item = new JMenuItem("Connect");
    private JMenuItem disconnect_item = new JMenuItem("Disconnect");
    private JMenuItem exit_item = new JMenuItem("Exit");
    private JMenuItem about_item = new JMenuItem("About");

    // Define handler and status.
    private Handler handler = new Handler();
    private JLabel status = new JLabel("Disconnected");

    // Define folder choosers.
    private JLabel share_folder = new JLabel("Share folder:");
    private JTextField share_field = new JTextField();
    private JButton share_set = new JButton("Select");
    private JLabel download_folder = new JLabel("Download folder:");
    private JTextField download_field = new JTextField();
    private JButton download_set = new JButton("Select");
    private JFileChooser choose_folder = new JFileChooser();

    // Define lists.
    private JLabel downloaded_files = new JLabel("Downloaded files:");
    private DefaultListModel<String> downloaded_list = new DefaultListModel<>();
    private JScrollPane download_pane = new JScrollPane(new JList<>(downloaded_list));
    private JLabel found_files = new JLabel("Found files:");
    private DefaultListModel<String> found_list = new DefaultListModel<>();
    private JList<String> list = new JList<>(found_list);
    private JScrollPane found_pane = new JScrollPane(list);
    private List<String> info_list = new ArrayList<>();

    public static void main(String[] args) {
        new user_interface("Tacha Torrent " + address);
    }

    // Constructor
    public user_interface(String name) {
        super(name);

        setSize(600, 600);
        setResizable(false);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setDefaultCloseOperation(JFrame.DO_NOTHING_ON_CLOSE);
        setLayout(null);

        addWindowListener(new WindowAdapter() {
            @Override
            public void windowClosing(WindowEvent we) {
                if (is_connected)
                    peer.disconnect();

                System.exit(0);
            }
        });

        setJMenuBar(bar);

        // Create files menu.
        bar.add(files_menu);
        files_menu.add(connect_item);
        files_menu.add(disconnect_item);
        files_menu.add(exit_item);

        // Create help menu.
        bar.add(help_menu);
        help_menu.add(about_item);

        // Add item functionalities.
        connect_item.addActionListener(handler);
        disconnect_item.addActionListener(handler);
        exit_item.addActionListener(handler);
        about_item.addActionListener(handler);

        // Create status text.
        status.setBounds(490, 10, 150, 20);
        status.setFont(new Font("Tahoma", Font.BOLD, 13));
        status.setForeground(java.awt.Color.RED);
        add(status);

        // Create share folder area.
        share_folder.setFont(new Font("Tahoma", Font.BOLD, 13));
        share_folder.setBounds(20, 10, 550, 25);
        add(share_folder);

        share_field.setBounds(20, 40, 460, 25);
        add(share_field);

        share_set.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent ae) {
                choose_folder.setFileSelectionMode(JFileChooser.DIRECTORIES_ONLY);
                int result = choose_folder.showOpenDialog(null);

                if (result == JFileChooser.APPROVE_OPTION) {
                    File selectedFolder = choose_folder.getSelectedFile();
                    share_field.setText(selectedFolder.getAbsolutePath());
                }
            }
        });

        share_set.setFont(new Font("Tahoma", Font.BOLD, 10));
        share_set.setBounds(490, 40, 75, 25);
        add(share_set);

        // Create download folder area.
        download_folder.setFont(new Font("Tahoma", Font.BOLD, 13));
        download_folder.setBounds(20, 70, 550, 25);
        add(download_folder);

        download_field.setBounds(20, 100, 460, 25);
        add(download_field);

        download_set.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent ae) {
                choose_folder.setFileSelectionMode(JFileChooser.DIRECTORIES_ONLY);
                int result = choose_folder.showOpenDialog(null);

                if (result == JFileChooser.APPROVE_OPTION) {
                    File selectedFolder = choose_folder.getSelectedFile();
                    download_field.setText(selectedFolder.getAbsolutePath());
                }
            }
        });

        download_set.setFont(new Font("Tahoma", Font.BOLD, 10));
        download_set.setBounds(490, 100, 75, 25);
        add(download_set);

        // Create downloaded files list.
        downloaded_files.setFont(new Font("Tahoma", Font.BOLD, 13));
        downloaded_files.setBounds(20, 130, 550, 25);
        add(downloaded_files);

        download_pane.setBounds(20, 160, 545, 150);
        add(download_pane);

        // Create found files list.
        found_files.setFont(new Font("Tahoma", Font.BOLD, 13));
        found_files.setBounds(20, 330, 550, 25);
        add(found_files);

        found_pane.setBounds(20, 360, 545, 150);
        add(found_pane);

        list.addListSelectionListener(new ListSelectionListener() {
            @Override
            public void valueChanged(ListSelectionEvent le) {
                if (le.getValueIsAdjusting() == false) {
                    String value = list.getSelectedValue();
                    int index = list.getSelectedIndex();

                    if (peer.is_downloading == true) {
                        JOptionPane.showMessageDialog(user_interface.this, "A file is already downloading!", "Download Warning", JOptionPane.WARNING_MESSAGE);
                        list.clearSelection();
                        return;
                    }

                    if (value == null || index == -1) {
                        list.clearSelection();
                        return;
                    }

                    value = value.substring(0, value.indexOf(" from "));

                    if (check_path(download_field) == true) {
                        int response = JOptionPane.showConfirmDialog(user_interface.this, "Do you want to download " + value + "?", "Confirm", JOptionPane.YES_NO_OPTION);

                        if (response == JOptionPane.YES_OPTION == true) {
                            downloaded_list.addElement(value + "    %0");
                            String text = download_field.getText();

                            new Thread(() -> {
                                try {
                                    peer.download(text, downloaded_list.size() - 1, info_list.get(index));
                                }

                                catch (IOException | InterruptedException exception) {
                                    JOptionPane.showMessageDialog(user_interface.this, "Connection failed!", "Download Error", JOptionPane.ERROR_MESSAGE);
                                }
                            }).start();
                        }
                    }

                    else
                        JOptionPane.showMessageDialog(user_interface.this, "Download folder is invalid!", "Download Warning", JOptionPane.WARNING_MESSAGE);

                    list.clearSelection();
                }
            }
        });

        setVisible(true);
    }

    // Check if the folder path is valid.
    private boolean check_path(JTextField text_field) {
        File directory = new File(text_field.getText());
        return (directory.exists() && directory.isDirectory());
    }

    // Get the path of the share folder.
    public String get_share_folder() {
        if (check_path(share_field) == false)
            return "";

        return share_field.getText();
    }

    // Change file size units.
    public static String change_units(String string) {
        String[] units = {"B", "KB", "MB", "GB", "TB"};
        int index = 0;
        double size = Long.parseLong(string);

        while (size >= 1024 && index < units.length - 1) {
            size = size / 1024.0;
            index = index + 1;
        }

        return String.format("%.2f %s", size, units[index]);
    }

    // Check if this client is the owner of this address.
    public boolean is_owner(String address) {
        if (addresses.contains(address) == false)
            return false;

        if (user_interface.address.equals(address) == false)
            setTitle("Tacha Torrent " + address);

        return true;
    }

    // Update the percentage of the downloaded files.
    public void update_percentage(int index, double l) {
        String item = downloaded_list.get(index);
        downloaded_list.set(index, String.format("%s %.2f",  item.substring(0, item.indexOf('%') + 1), l * 100));
    }

    // Scan for the found files.
    public void refresh_found_list(String string, String received_message) {
        if (received_message.equals("") == true) {
            for (int i = 0; i < found_list.getSize(); i++)
                if (found_list.getElementAt(i).contains(string)) {
                    info_list.remove(i);
                    found_list.remove(i--);
                }
            return;
        }

        String[] file_infos = received_message.split(";");
        int size = file_infos.length;
        String[] files = new String[size];
        String[] bytes = new String[size];
        int index = 0;

        for (int i = 0; i < size; i++) {
            String[] info = file_infos[i].split("~");

            // name
            files[i] = info[0];

            // length
            bytes[i] = info[2];
        }

        for (int i = 0; i < found_list.getSize(); i++) {
            if (found_list.getElementAt(i).contains(string) == true) {
                if (index == size) {
                    info_list.remove(i);
                    found_list.remove(i--);
                }

                else {
                    info_list.set(i, file_infos[index]);
                    found_list.set(i, files[index] + " " + change_units(bytes[index++]) + " from " + string);
                }
            }
        }

        for (int i = index; i < size; i++) {
            info_list.add(file_infos[i]);
            found_list.addElement(files[i] + " " + change_units(bytes[i]) + " from " + string);
        }
    }

    // Handler for the menu bar items.
    private class Handler implements ActionListener {
        @Override
        public void actionPerformed(ActionEvent ae) {
            if (ae.getSource() == connect_item) {
                if (is_connected == false) {
                    is_connected = true;
                    status.setText("Connected");
                    status.setForeground(java.awt.Color.GREEN);
                    peer.connect();
                }
            }

            else if (ae.getSource() == disconnect_item) {
                if (is_connected) {
                    is_connected = false;
                    status.setText("Disconnected");
                    status.setForeground(java.awt.Color.RED);
                    found_list.clear();
                    peer.disconnect();
                }
            }

            else if (ae.getSource() == exit_item) {
                if (is_connected)
                    peer.disconnect();

                System.exit(0);
            }

            else if (ae.getSource() == about_item)
                JOptionPane.showMessageDialog(user_interface.this, "Name & Surname: Eren Dumlupinar\nSchool Number: 20210702006");
        }
    }

    // Save addresses.
    static {
        try {
            Enumeration<NetworkInterface> network_interfaces = NetworkInterface.getNetworkInterfaces();
            NetworkInterface network_interface;
            Enumeration<InetAddress> inet_addresses;
            InetAddress inet_address;
            boolean is_self;

            while (network_interfaces.hasMoreElements() == true) {
                network_interface = network_interfaces.nextElement();

                if (network_interface.isLoopback() == true || network_interface.isUp() == false)
                    continue;

                inet_addresses = network_interface.getInetAddresses();
                is_self = true;

                while (inet_addresses.hasMoreElements() == true) {
                    inet_address = inet_addresses.nextElement();

                    if (inet_address instanceof Inet4Address == true) {
                        addresses.add(inet_address.getHostAddress());

                        if (is_self == true) {
                            address = inet_address.getHostAddress();
                            is_self = false;
                        }
                    }
                }
            }
        }

        catch (IOException io) {
            io.printStackTrace();
            System.exit(1);
        }
    }
}