tugas image viewer

Pada kesempatan kali ini saya akan menampilkan sebuah program aplikasi Image Viewer. Image Viewer sendiri adalah aplikasi yang dapat menampilkan sebuah gambar

1. Source Code ImageViewer

  /**   
  * Write a description of class ImageViewer here.   
  *   
  * @author muhammad irfan   
  * @version 1.0   
  */   
  import java.awt.*;   
  import java.awt.event.*;   
  import javax.swing.*;   
  public class ImageViewer   
  {   
   private JFrame frame;   
   private ImagePanel imagePanel;   
   /**   
   * Create an ImageViewer show it on screen.   
   */   
   public ImageViewer()   
   {   
    makeFrame();   
   }   
   // ---- implementation of menu functions ----   
   /**   
   * Open function: open a file chooser to select a new image file.   
   */   
   private void openFile()   
   {   
    OFImage image = ImageFileManager.getImage();   
    imagePanel.setImage(image);   
    frame.pack();   
   }   
   /**   
   * Quit function: quit the application.   
   */   
   private void quit()   
   {   
    System.exit(0);   
   }   
   // ---- swing stuff to build the frame and all its components ----   
   /**   
   * Create the Swing frame and its content.   
   */   
   private void makeFrame()   
   {   
    frame = new JFrame("ImageViewer");   
    makeMenuBar(frame);   
    Container contentPane = frame.getContentPane();   
    imagePanel = new ImagePanel();   
    contentPane.add(imagePanel);   
    // building is done - arrange the components and show     
    frame.pack();   
    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)   
   {   
    final int SHORTCUT_MASK =   
     Toolkit.getDefaultToolkit().getMenuShortcutKeyMask();   
    JMenuBar menubar = new JMenuBar();   
    frame.setJMenuBar(menubar);   
    // create the File manu   
    JMenu fileMenu = new JMenu("File");   
    menubar.add(fileMenu);   
    JMenuItem openItem = new JMenuItem("Open");   
     openItem.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_O, SHORTCUT_MASK));   
     openItem.addActionListener(new ActionListener() {   
          public void actionPerformed(ActionEvent e) { openFile(); }   
         });   
    fileMenu.add(openItem);   
    JMenuItem quitItem = new JMenuItem("Quit");   
     quitItem.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_Q, SHORTCUT_MASK));   
     quitItem.addActionListener(new ActionListener() {   
       public void actionPerformed(ActionEvent e) { quit(); }   
     });   
    fileMenu.add(quitItem);   
   }   
  }   

2. Source Code ImageFileManager

 /**   
  * Write a description of class ImageFileManager here.   
  *   
  * @author muhammad irfan   
  * @version 1.0   
  */   
  import java.awt.image.*;   
  import javax.imageio.*;   
  import javax.swing.*;   
  import java.io.*;   
  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";   
   private static JFileChooser fileChooser = new JFileChooser(System.getProperty("user.dir"));   
   /**   
   * Open a file chooser and let the user select an image file in the file   
   * system. Then read an image file from disk and return it as an image. 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.   
   *    
   * @return  The image object or null is it was not a valid image file.   
   */   
   public static OFImage getImage()   
   {   
    int returnVal = fileChooser.showOpenDialog(null);   
    if(returnVal != JFileChooser.APPROVE_OPTION) {   
     return null; // cancelled   
    }   
    File selectedFile = fileChooser.getSelectedFile();   
    return loadImage(selectedFile);   
   }   
   /**   
   * Read an image file from disk and return it as a BufferedImage. 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 image object or null is it was not a valid image file.   
   */   
   public static OFImage loadImage(File imageFile)   
   {   
    try {   
     BufferedImage image = ImageIO.read(imageFile);   
     if(image == null || (image.getWidth(null) < 0)) {   
      // we could not load the image - probably invalid file format   
      return null;   
     }   
     return new OFImage(image);   
    }   
    catch(IOException exc) {   
     return null;   
    }   
   }   
   /**   
   * Write an image file to disk. The file format is JPG. In case of any problem   
   * the method just silently returns.   
   *    
   * @param image The image 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) {   
     return;   
    }   
   }   
  }  

3.  Source Code ImagePanel

 /**   
  * Write a description of class ImagePanel here.   
  *   
  * @author muhammad irfan  
  * @version 1.0   
  */   
  import java.awt.*;   
  import javax.swing.*;   
  import java.awt.image.*;   
  public class ImagePanel extends JComponent   
  {   
   // The current width and height of this panel   
   private int width, height;   
   // An internal image buffer that is used for painting. For   
   // actual display, this image buffer is then copied to screen.   
   private OFImage panelImage;   
   /**   
   * Create a new, empty ImagePanel.   
   */   
   public ImagePanel()   
   {   
    width = 360; // arbitrary size for empty panel   
    height = 240;   
    panelImage = null;   
   }   
   /**   
   * Set the image that this panel should show.   
   *    
   * @param image The image to be displayed.   
   */   
   public void setImage(OFImage image)   
   {   
    if(image != null) {   
     width = image.getWidth();   
     height = image.getHeight();   
     panelImage = image;   
     repaint();   
    }   
   }   
   /**   
   * Clear the image on this panel.   
   */   
   public void clearImage()   
   {   
    Graphics imageGraphics = panelImage.getGraphics();   
    imageGraphics.setColor(Color.LIGHT_GRAY);   
    imageGraphics.fillRect(0, 0, width, height);   
    repaint();   
   }   
   // The following methods are redefinitions of methods   
   // inherited from superclasses.   
   /**   
   * Tell the layout manager how big we would like to be.   
   * (This method gets called by layout managers for placing   
   * the components.)   
   *    
   * @return The preferred dimension for this component.   
   */   
   public Dimension getPreferredSize()   
   {   
    return new Dimension(width, height);   
   }   
   /**   
   * This component needs to be redisplayed. Copy the internal image    
   * to screen. (This method gets called by the Swing screen painter    
   * every time it want this component displayed.)   
   *    
   * @param g The graphics context that can be used to draw on this component.   
   */   
   public void paintComponent(Graphics g)   
   {   
    Dimension size = getSize();   
    g.clearRect(0, 0, size.width, size.height);   
    if(panelImage != null) {   
     g.drawImage(panelImage, 0, 0, null);   
    }   
   }   
  }   

4. Source Code OFImage

 /**   
  * Write a description of class OFImage here.   
  *   
  * @author muhammad irfan  
  * @version 1.0   
  */   
  import java.awt.*;   
  import java.awt.image.*;   
  import javax.swing.*;   
  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);   
   }   
  }