Tugas PBO 14 GUI & Panel Login

Nama : Afel Allaric Absor
NRP   : 5025231140
Kelas  : PBO (A)

                                                     Tugas 14 GUI Image Viewer & Panel Login

1). Image Viewer

- Isi file ImageViewer.java :

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

/**
 * ImageViewer is the main class of the image viewer application. It builds and
 * displays the application GUI and initializes all other components.
 *
 * To start the application, create an object of this class.
 *
 * @author Michael Kolling and David J Barnes
 * @version 1.0
 */
public class ImageViewer {
    // Static fields
    private static final String VERSION = "Version 1.0";
    private static JFileChooser fileChooser = new JFileChooser(System.getProperty("user.dir"));

    // Instance fields
    private JFrame frame;
    private ImagePanel imagePanel;
    private JLabel filenameLabel;
    private JLabel statusLabel;
    private OFImage currentImage;

    /**
     * Main constructor. Create an ImageViewer and show it on screen.
     */
    public ImageViewer() {
        makeFrame();
    }

    /**
     * Open a file dialog to load an image file.
     */
    private void openFile() {
        int returnVal = fileChooser.showOpenDialog(frame);
        if (returnVal != JFileChooser.APPROVE_OPTION) {
            return; // cancelled
        }

        File selectedFile = fileChooser.getSelectedFile();
        currentImage = ImageFileManager.loadImage(selectedFile);
        if (currentImage == null) {
            JOptionPane.showMessageDialog(frame,
                    "The file was not in a recognized image file format.",
                    "Image Load Error",
                    JOptionPane.ERROR_MESSAGE);
            return;
        }

        imagePanel.setImage(currentImage);
        showFilename(selectedFile.getPath());
        showStatus("File loaded.");
        frame.pack();
    }

    /**
     * Close the currently loaded image.
     */
    private void close() {
        currentImage = null;
        imagePanel.clearImage();
        showFilename(null);
        showStatus("Image closed.");
    }

    /**
     * Quit the application.
     */
    private void quit() {
        System.exit(0);
    }

    /**
     * Apply a "darker" filter to the image.
     */
    private void makeDarker() {
        if (currentImage != null) {
            currentImage.darker();
            frame.repaint();
            showStatus("Applied: darker");
        } else {
            showStatus("No image loaded.");
        }
    }

    /**
     * Apply a "lighter" filter to the image.
     */
    private void makeLighter() {
        if (currentImage != null) {
            currentImage.lighter();
            frame.repaint();
            showStatus("Applied: lighter");
        } else {
            showStatus("No image loaded.");
        }
    }

    /**
     * Apply a "threshold" filter to the image.
     */
    private void threshold() {
        if (currentImage != null) {
            currentImage.threshold();
            frame.repaint();
            showStatus("Applied: threshold");
        } else {
            showStatus("No image loaded.");
        }
    }

    /**
     * Show an "About" dialog.
     */
    private void showAbout() {
        JOptionPane.showMessageDialog(frame,
                "ImageViewer\n" + VERSION,
                "About ImageViewer",
                JOptionPane.INFORMATION_MESSAGE);
    }

    // ---- Support Methods ----

    /**
     * Display a file name on the filename label.
     *
     * @param filename The file name to be displayed.
     */
    private void showFilename(String filename) {
        if (filename == null) {
            filenameLabel.setText("No file displayed.");
        } else {
            filenameLabel.setText("File: " + filename);
        }
    }

    /**
     * Display a status message in the status bar.
     *
     * @param text The status message to be displayed.
     */
    private void showStatus(String text) {
        statusLabel.setText(text);
    }

    // ---- GUI Construction ----

    /**
     * Create the Swing frame and its content.
     */
    private void makeFrame() {
        frame = new JFrame("ImageViewer");
        makeMenuBar(frame);

        Container contentPane = frame.getContentPane();
        contentPane.setLayout(new BorderLayout(6, 6));

        filenameLabel = new JLabel("No file displayed.");
        contentPane.add(filenameLabel, BorderLayout.NORTH);

        imagePanel = new ImagePanel();
        contentPane.add(imagePanel, BorderLayout.CENTER);

        statusLabel = new JLabel(VERSION);
        contentPane.add(statusLabel, BorderLayout.SOUTH);

        frame.pack();
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        Dimension d = Toolkit.getDefaultToolkit().getScreenSize();
        frame.setLocation(d.width / 2 - frame.getWidth() / 2, d.height / 2 - frame.getHeight() / 2);
        frame.setVisible(true);
    }

    /**
     * Create the main frame's menu bar.
     *
     * @param frame The frame that the menu bar should be added to.
     */
    private void makeMenuBar(JFrame frame) {
        JMenuBar menubar = new JMenuBar();
        frame.setJMenuBar(menubar);

        JMenu menu;
        JMenuItem item;

        // File menu
        menu = new JMenu("File");
        menubar.add(menu);

        item = new JMenuItem("Open");
        item.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_O, ActionEvent.CTRL_MASK));
        item.addActionListener(e -> openFile());
        menu.add(item);

        item = new JMenuItem("Close");
        item.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_W, ActionEvent.CTRL_MASK));
        item.addActionListener(e -> close());
        menu.add(item);

        menu.addSeparator();

        item = new JMenuItem("Quit");
        item.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_Q, ActionEvent.CTRL_MASK));
        item.addActionListener(e -> quit());
        menu.add(item);

        // Filter menu
        menu = new JMenu("Filter");
        menubar.add(menu);

        item = new JMenuItem("Darker");
        item.addActionListener(e -> makeDarker());
        menu.add(item);

        item = new JMenuItem("Lighter");
        item.addActionListener(e -> makeLighter());
        menu.add(item);

        item = new JMenuItem("Threshold");
        item.addActionListener(e -> threshold());
        menu.add(item);

        // Help menu
        menu = new JMenu("Help");
        menubar.add(menu);

        item = new JMenuItem("About ImageViewer...");
        item.addActionListener(e -> showAbout());
        menu.add(item);
    }

    public static void main(String[] args) {
        new ImageViewer();
    }
}

- Isi file ImagePanel.java :

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

public class ImagePanel extends JPanel {
    private OFImage image;

    public void setImage(OFImage image) {
        this.image = image;
        repaint();
    }

    public void clearImage() {
        this.image = null;
        repaint();
    }

    @Override
    protected void paintComponent(Graphics g) {
        super.paintComponent(g);
        if (image != null) {
            g.drawImage(image, 0, 0, getWidth(), getHeight(), null);
        }
    }
}

- Isi file ImageFileManager.java :

import java.awt.image.*;
import javax.imageio.*;
import java.io.*;

/**
 * ImageFileManager is a utility class with static methods to load and save images.
 *
 * The files on disk can be in JPG or PNG image format. For files written
 * by this class, the format is determined by the constant IMAGE_FORMAT.
 *
 * @author Michael Kolling and David J Barnes
 * @version 2.0
 */
public class ImageFileManager {
    // A constant for the image format that this writer uses for writing.
    // Available formats are "jpg" and "png".
    private static final String IMAGE_FORMAT = "jpg";

    /**
     * Read an image file from disk and return it as an OFImage object.
     * This method can read JPG and PNG file formats.
     * In case of any problem (e.g., the file does not exist, is in an undecodable format,
     * or any other read error), this method returns null.
     *
     * @param imageFile The image file to be loaded.
     * @return The OFImage object or null if it could not be read.
     */
    public static OFImage loadImage(File imageFile) {
        try {
            BufferedImage image = ImageIO.read(imageFile);
            if (image == null) {
                // Could not load the image - probably an invalid file format
                return null;
            }
            return new OFImage(image);
        } catch (IOException exc) {
            // Return null if an error occurs while reading the image
            return null;
        }
    }

    /**
     * Write an OFImage object to disk. The file format is determined by IMAGE_FORMAT.
     * In case of any problem, the method silently returns.
     *
     * @param image The OFImage object to be saved.
     * @param file  The file to save to.
     */
    public static void saveImage(OFImage image, File file) {
        try {
            ImageIO.write(image, IMAGE_FORMAT, file);
        } catch (IOException exc) {
            // Silently handle any errors during image saving
        }
    }
}

- Isi File OFImage.java :

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

/**
 * OFImage is a class that defines an image in OF (Objects First) format.
 * It extends BufferedImage to add additional functionality for manipulating images.
 *
 * @author Michael Kolling and David J. Barnes
 * @version 1.1
 */
public class OFImage extends BufferedImage {

    /**
     * Create an OFImage copied from a BufferedImage.
     *
     * @param image The image to copy.
     */
    public OFImage(BufferedImage image) {
        super(image.getColorModel(), image.copyData(null),
                image.isAlphaPremultiplied(), null);
    }

    /**
     * Create an OFImage with specified size and unspecified content.
     *
     * @param width  The width of the image.
     * @param height The height of the image.
     */
    public OFImage(int width, int height) {
        super(width, height, TYPE_INT_RGB);
    }

    /**
     * Set a given pixel of this image to a specified color.
     * The color is represented as an (r,g,b) value.
     *
     * @param x   The x position of the pixel.
     * @param y   The y position of the pixel.
     * @param col The color of the pixel.
     */
    public void setPixel(int x, int y, Color col) {
        int pixel = col.getRGB();
        setRGB(x, y, pixel);
    }

    /**
     * Get the color value at a specified pixel position.
     *
     * @param x The x position of the pixel.
     * @param y The y position of the pixel.
     * @return The color of the pixel at the given position.
     */
    public Color getPixel(int x, int y) {
        int pixel = getRGB(x, y);
        return new Color(pixel);
    }

    /**
     * Make this image a bit darker.
     */
    public void darker() {
        int height = getHeight();
        int width = getWidth();
        for (int y = 0; y < height; y++) {
            for (int x = 0; x < width; x++) {
                setPixel(x, y, getPixel(x, y).darker());
            }
        }
    }

    /**
     * Make this image a bit lighter.
     */
    public void lighter() {
        int height = getHeight();
        int width = getWidth();
        for (int y = 0; y < height; y++) {
            for (int x = 0; x < width; x++) {
                setPixel(x, y, getPixel(x, y).brighter());
            }
        }
    }

    /**
     * Perform a three-level threshold operation.
     * Repaint the image with only three color values: white, gray, and black.
     */
    public void threshold() {
        int height = getHeight();
        int width = getWidth();
        for (int y = 0; y < height; y++) {
            for (int x = 0; x < width; x++) {
                Color pixel = getPixel(x, y);
                int brightness = (pixel.getRed() + pixel.getBlue() + pixel.getGreen()) / 3;
                if (brightness <= 85) {
                    setPixel(x, y, Color.BLACK);
                } else if (brightness <= 170) {
                    setPixel(x, y, Color.GRAY);
                } else {
                    setPixel(x, y, Color.WHITE);
                }
            }
        }
    }

}

- Hasil Kode saat dijalankan :

2). Panel Login 

- Isi file LoginPanel.java :

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

public class LoginPanel {
    public static void main(String[] args) {
        JFrame frame = new JFrame("Login Panel");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setSize(350, 200);
        frame.setLocationRelativeTo(null);

        JPanel panel = new JPanel();
        panel.setLayout(new GridBagLayout());
        frame.add(panel);

        JLabel usernameLabel = new JLabel("Username:");
        JLabel passwordLabel = new JLabel("Password:");
        JTextField usernameField = new JTextField(15);
        JPasswordField passwordField = new JPasswordField(15);
        JButton loginButton = new JButton("Login");
        JLabel messageLabel = new JLabel("");

        GridBagConstraints gbc = new GridBagConstraints();
        gbc.insets = new Insets(5, 5, 5, 5);
        gbc.gridx = 0;
        gbc.gridy = 0;
        panel.add(usernameLabel, gbc);

        gbc.gridx = 1;
        gbc.gridy = 0;
        panel.add(usernameField, gbc);

        gbc.gridx = 0;
        gbc.gridy = 1;
        panel.add(passwordLabel, gbc);

        gbc.gridx = 1;
        gbc.gridy = 1;
        panel.add(passwordField, gbc);

        gbc.gridx = 1;
        gbc.gridy = 2;
        panel.add(loginButton, gbc);

        gbc.gridx = 1;
        gbc.gridy = 3;
        panel.add(messageLabel, gbc);


        loginButton.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                String username = usernameField.getText();
                String password = new String(passwordField.getPassword());


                if (username.equals("admin") && password.equals("1234")) {
                    messageLabel.setText("Login berhasil! Selamat datang, " + username);
                    messageLabel.setForeground(Color.GREEN);
                } else {
                    messageLabel.setText("Username atau password salah!");
                    messageLabel.setForeground(Color.RED);
                }
            }
        });

        frame.setVisible(true);
    }
}

- Hasil dari kode saat dijalankan :

- Link repository github berisi kode : https://github.com/afelallaric/Tugas-PBO-14-GUI.git