BufferedImages and Swing's ScrollablePicture in a JPanel

Question

I'm referring to http://java.sun.com/developer/technicalArticles/Media/imagestrategies/index.html paper.
As I read this excellent paper, I decided to go for the BufferedImage strategy.
But I can't put my BufferedImage into my ScrollablePicture as below:
JPanel picPanel = new JPanel(new GridBagLayout());
//Set up the scroll pane.
picture = new ScrollablePicture(imageIcon_, columnView.getIncrement()); // OK
//picture = new ScrollablePicture(bImg, columnView.getIncrement()); // NOT OK = don't work
...How to bypass the message "java:542: cannot resolve symbol symbol : constructor ScrollablePicture (java.awt.image.BufferedImage,int)"
It is very important as all my code is based on BufferedImage to apply many operations on the image.
? I believe the API does not allow to perform RGB to B&W operation on ImageIcon. ?
Thanks to all.
dimitryous r.

Answer 1

Hi camickr,
Hi all,
I pass trough my SSCCE. Good advice from camickr. But it was not so easy:
Short: not so short
Self contained: believe so
Correct: Java 1.4.2 code
Compilable: yes
I'm back with formatted code.
I'm sure you will fire at me all of you. Anyway if I don't even try, I will never succeed.
//  TooAwoo.java
//  TooAwoo
//     part of this code is from Sun's JavaTutorial 1.4.2
import java.applet.Applet.*;
import java.awt.*;
import java.awt.event.*;
import java.awt.GraphicsEnvironment;
import java.awt.image.*;
import java.lang.*;
import java.lang.String;
import java.lang.Object;
import java.net.URL;
import java.net.MalformedURLException;
import javax.swing.*;
import javax.swing.event.*;
import javax.swing.event.MouseInputAdapter;
import javax.swing.ImageIcon;
import javax.swing.JScrollPane;
import javax.swing.JToggleButton;
import java.io.FilePermission;
public class TooAwoo extends JApplet implements
                                                            ChangeListener,
                                                            ActionListener,
                                                            ItemListener
     FilePermission p = new FilePermission("<<ALL FILES>>", "read,write");
    public BufferedImage bImg;
     Font newFont = new Font("SansSerif", Font.PLAIN, 10);
     ImageControls RightPanel;
     public static int initOx = 0;
     public static int initOy = 0;
     int init_ww, init_wh, set_x, set_y = 0;
     final int pSP_w = 520; // final width of pictureScrollPane
     final int pSP_h = 650; // final height of pictureScrollPane
     Dimension applet_window; // applet dimensions
     public Image image;
     public ImageIcon imageIcon_;
     public static BufferedImage binull;
     // ScrollablePicture stuff
     public Rule columnView;
    public Rule rowView;
     public JToggleButton isMetric;
    public ScrollablePicture picture;
     public JScrollPane pictureScrollPane;
     public TooAwoo() {
          // nothing here
    public void init() {
          applet_window = getSize();                                                            // read applet dimensions in TooAwoo.html
          init_ww = applet_window.width;
          init_wh = applet_window.height;
          // get the image to use width > 680 (see final int pSP_w above)
          image = getImage(getDocumentBase(), "images/ReallyBig.jpg");
          imageIcon_ = createImageIcon("images/ReallyBig.jpg");
          int iw = imageIcon_.getIconWidth();
          int ih = imageIcon_.getIconHeight();
          bImg = new BufferedImage(iw, ih, BufferedImage.TYPE_INT_RGB);
          // Panels
          // ImageDisplayPanel
        //Create the row and column headers.
        columnView = new Rule(Rule.HORIZONTAL, true);
        rowView = new Rule(Rule.VERTICAL, true);
        if (imageIcon_ != null) {
            columnView.setPreferredWidth(imageIcon_.getIconWidth());
            rowView.setPreferredHeight(imageIcon_.getIconHeight());
        } else {
            columnView.setPreferredWidth(640);
            rowView.setPreferredHeight(480);
        //Create the upper left corner.
        JPanel buttonCorner = new JPanel();                                                  //use FlowLayout
        isMetric = new JToggleButton("cm", true);
        isMetric.setFont(newFont);
        isMetric.setMargin(new Insets(2,2,2,2));
        isMetric.addItemListener(this);                                                       // !!! not OK = don't work: button is not firing
        buttonCorner.add(isMetric);
          JPanel ImageDisplayPanel = new JPanel(new GridBagLayout());
        //Set up the scroll pane.
          picture = new ScrollablePicture(imageIcon_, columnView.getIncrement());     // either
          //picture = new ScrollablePicture(bImp, columnView.getIncrement());          // or
          // ********** if bImp change the lines in ScrollablePicture.java **********
        Graphics g = bImg.getGraphics();
          g.drawImage(bImg, 0, 0, null);
          JScrollPane pictureScrollPane = new JScrollPane(picture);
        pictureScrollPane.setPreferredSize(new Dimension(pSP_w, pSP_h));
        pictureScrollPane.setViewportBorder(
                BorderFactory.createLineBorder(Color.black));
        pictureScrollPane.setColumnHeaderView(columnView);
        pictureScrollPane.setRowHeaderView(rowView);
          //Set the corners.
        pictureScrollPane.setCorner(JScrollPane.UPPER_LEFT_CORNER, buttonCorner);
        pictureScrollPane.setCorner(JScrollPane.LOWER_LEFT_CORNER,
                                    new Corner());
        pictureScrollPane.setCorner(JScrollPane.UPPER_RIGHT_CORNER,
                                    new Corner());
          //set_y++;
          addToGridBag(ImageDisplayPanel,pictureScrollPane, set_x, set_y, 1, 1, 0, 0); // 0,0
          getContentPane().add( BorderLayout.WEST, ImageDisplayPanel);               // where to display the bImg: left
          RightPanel = new ImageControls();                                                  // call the ImageControls class
          RightPanel.setBackground(Color.black);
          getContentPane().add( BorderLayout.EAST, RightPanel);
          //getContentPane().add( BorderLayout.EAST, ToolsPanel);                         // where to display the tools: right
          JPanel GlobalPanel = new JPanel(new GridBagLayout());
          getContentPane().add( BorderLayout.NORTH, GlobalPanel);
     } // end public void init()
     public Graphics2D createGraphics2D(int width,
                                                int height,
                                                BufferedImage bi,
                                                Graphics g) {                                   // called by ImageControls paint
          Graphics2D g2 = null;
          if (bi != null) {
               System.out.println("TooAwoo createGraphics2D: bi != null : " + " w= " + width + " h= " + height);
               g2 = bi.createGraphics();
          } else {
               System.out.println("TooAwoo createGraphics2D: bi == null g2 = (Graphics2D) g");
               g2 = (Graphics2D) g;
          return g2; // return to ImageControls paint
     } // end createGraphics2D
     class ImageControls extends JPanel {
          public void paint(Graphics g) {
               Dimension applet_window = getSize();
               if (bImg == null) {
                    bImg = createBufferedImage(applet_window.width, applet_window.height, 2);
               } else {
                    Graphics2D g2 = createGraphics2D(applet_window.width, applet_window.height, bImg, g);
                    g.drawImage( bImg , initOx , initOy , null );
                    g2.dispose();
                    //toolkit.sync();
               } // end else (bImg != null)
          } // end paint
     } // end ImageControls
     public Dimension setPreferredSize() {
          Dimension applet_window = getSize();
          return applet_window;
     public String getString(String key) {
          return key;
     public BufferedImage createBufferedImage(int w, int h, int imgType) {          // called by ImageControls paint
          BufferedImage bi = null;
          if (imgType == 0) {
               bi = (BufferedImage) getGraphicsConfiguration().createCompatibleImage(w, h);
          } else if (imgType > 0 && imgType < 14) {
               bi = new BufferedImage(w, h, imgType);
          System.out.println("TooAwoo createBufferedImage: imgType= " + imgType + " w= " + w + " h= " + h);
          return bi;
     public static void addToGridBag(JPanel panel, Component comp,
                                             int x, int y, int w, int h, double weightx, double weighty) {
          GridBagLayout gbl = (GridBagLayout) panel.getLayout();
          GridBagConstraints c = new GridBagConstraints();
          c.fill = GridBagConstraints.BOTH;
          c.anchor = GridBagConstraints.WEST;
          c.gridx = x;
          c.gridy = y;
          c.gridwidth = w;
          c.gridheight = h;
          c.weightx = weightx;
          c.weighty = weighty;
          panel.add(comp);
          gbl.setConstraints(comp, c);
     } // end addToGridBag
     protected static ImageIcon createImageIcon(String path) {                         // Returns an ImageIcon, or null if the path was invalid.
          java.net.URL imgURL = TooAwoo.class.getResource(path);
          if (imgURL != null) {
               return new ImageIcon(imgURL);
          } else {
               System.err.println("Couldn't find file: " + path);
               return null;
     } // end createImageIcon
     private static void createAndShowGUI() {                                             // called by main
          JFrame frame = new JFrame("TooAwoo");                                             //Create and set up the window.
          // Make sure we have nice window decorations.
          frame.setDefaultLookAndFeelDecorated(true);
          frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
          // Create and set up content pane.
          frame.addWindowListener(new WindowAdapter() {
               public void windowClosing(WindowEvent e) {
                    System.exit(0);
          JPanel masterPanel = new JPanel();
          frame.add("Center", masterPanel);
          // Display the window.
          frame.pack();
          frame.setSize(new Dimension( 1000 , 640 ));
          frame.setVisible(true);
     } // end createAndShowGUI
     public static void main(String s[]) {
        javax.swing.SwingUtilities.invokeLater(new Runnable() {
               public void run() {
                    createAndShowGUI();
     } // end main
     public void actionPerformed(ActionEvent e) {
          repaint(1024);
    public void stateChanged(ChangeEvent e) {
          repaint(1024);
     public void itemStateChanged(ItemEvent e) {
          Object obj = e.getSource();
          if ( obj == isMetric ) {
               System.out.println("obj isMetric");
            //Turn it to metric.
            rowView.setIsMetric(true);
            columnView.setIsMetric(true);
               picture.setMaxUnitIncrement(rowView.getIncrement());
        } else {
            System.out.println("obj isNotMetric");
               //Turn it to inches.
            rowView.setIsMetric(false);
            columnView.setIsMetric(false);
               picture.setMaxUnitIncrement(rowView.getIncrement());
     } // end itemStateChanged(ItemEvent e)
} // end TooAwoo
Next is ScrollablePicture.java
import java.awt.*;
import java.awt.event.*;
import java.awt.image.*;
import javax.swing.*;
import javax.swing.border.*;
public class ScrollablePicture extends JLabel implements Scrollable {
    private int maxUnitIncrement = 1;
     private boolean missingPicture = false;
    public ScrollablePicture (ImageIcon imageIcon_, int m){                              //(BufferedImage bImg, int m)
        super(imageIcon_); // comment this line if bImg...
          if (imageIcon_ == null) { // change imageIcon_ to bImg if bImg...
               missingPicture = true;
               setText("No picture found.");
               setHorizontalAlignment(CENTER);
               setOpaque(true);
               setBackground(Color.black);
          maxUnitIncrement = m;
    public Dimension getPreferredScrollableViewportSize() {
        return getPreferredSize();
    public int getScrollableUnitIncrement(Rectangle visibleRect,
                                          int orientation,
                                          int direction) {
        //Get the current position.
        int currentPosition = 0;
        if (orientation == SwingConstants.HORIZONTAL)
            currentPosition = visibleRect.x;
        else
            currentPosition = visibleRect.y;
        //Return the number of pixels between currentPosition
        //and the nearest tick mark in the indicated direction.
        if (direction < 0) {
            int newPosition = currentPosition -
               (currentPosition / maxUnitIncrement) *
               maxUnitIncrement;
            return (newPosition == 0) ? maxUnitIncrement : newPosition;
        } else {
            return ((currentPosition / maxUnitIncrement) + 1) *
               maxUnitIncrement - currentPosition;
    public int getScrollableBlockIncrement(Rectangle visibleRect,
                                           int orientation,
                                           int direction) {
        if (orientation == SwingConstants.HORIZONTAL)
            return visibleRect.width - maxUnitIncrement;
        else
            return visibleRect.height - maxUnitIncrement;
    public boolean getScrollableTracksViewportWidth() {
        return false;
    public boolean getScrollableTracksViewportHeight() {
        return false;
    public void setMaxUnitIncrement(int pixels) {
        maxUnitIncrement = pixels;
Next is Corner.java
import java.awt.*;
import javax.swing.*;
public class Corner extends JComponent {
    protected void paintComponent(Graphics g) {
        g.setColor(new Color(230, 163, 4));
        g.fillRect(0, 0, getWidth(), getHeight());
Next is Rule.java
import java.awt.*;
import javax.swing.*;
public class Rule extends JComponent {
    public static final int INCH = Toolkit.getDefaultToolkit().
            getScreenResolution();
    public static final int HORIZONTAL = 0;
    public static final int VERTICAL = 1;
    public static final int SIZE = 30;
    public int orientation;
    public boolean isMetric;
    private int increment;
    private int units;
    public Rule(int o, boolean m) {
        orientation = o;
        isMetric = m;
        setIncrementAndUnits();
    public void setIsMetric(boolean isMetric) {
        this.isMetric = isMetric;
        setIncrementAndUnits();
        repaint();
    private void setIncrementAndUnits() {
        if (isMetric) {
            units = (int)((double)INCH / (double)2.54); // dots per centimeter
            increment = units;
        } else {
            units = INCH;
            increment = units / 2;
    public boolean isMetric() {
        return this.isMetric;
    public int getIncrement() {
        return increment;
    public void setPreferredHeight(int ph) {
        setPreferredSize(new Dimension(SIZE, ph));
    public void setPreferredWidth(int pw) {
        setPreferredSize(new Dimension(pw, SIZE));
    protected void paintComponent(Graphics g) {
        Rectangle drawHere = g.getClipBounds();
        // Fill clipping area with dirty brown/orange.
        g.setColor(new Color(230, 163, 4));
        g.fillRect(drawHere.x, drawHere.y, drawHere.width, drawHere.height);
        // Do the ruler labels in a small font that's black.
        g.setFont(new Font("SansSerif", Font.PLAIN, 10));
        g.setColor(Color.black);
        // Some vars we need.
        int end = 0;
        int start = 0;
        int tickLength = 0;
        String text = null;
        // Use clipping bounds to calculate first and last tick locations.
        if (orientation == HORIZONTAL) {
            start = (drawHere.x / increment) * increment;
            end = (((drawHere.x + drawHere.width) / increment) + 1)
                  * increment;
        } else {
            start = (drawHere.y / increment) * increment;
            end = (((drawHere.y + drawHere.height) / increment) + 1)
                  * increment;
        // Make a special case of 0 to display the number
        // within the rule and draw a units label.
        if (start == 0) {
            text = Integer.toString(0) + (isMetric ? " cm" : " in");
            tickLength = 8;//10;
            if (orientation == HORIZONTAL) {
                g.drawLine(0, SIZE-1, 0, SIZE-tickLength-1);
                g.drawString(text, 2, 21);
            } else {
                g.drawLine(SIZE-1, 0, SIZE-tickLength-1, 0);
                g.drawString(text, 9, 10);
            text = null;
            start = increment;
        // ticks and labels
        for (int i = start; i < end; i += increment) {
            if (i % units == 0)  {
                tickLength = 7;//10;
                text = Integer.toString(i/units);
            } else {
                tickLength = 4;//7;
                text = null;
            if (tickLength != 0) {
                if (orientation == HORIZONTAL) {
                    g.drawLine(i, SIZE-1, i, SIZE-tickLength-1);
                    if (text != null)
                        g.drawString(text, i-3, 21);
                } else {
                    g.drawLine(SIZE-1, i, SIZE-tickLength-1, i);
                    if (text != null)
                        g.drawString(text, 9, i+3);
Here is TooAwoo.html
<HTML>
<HEAD>
<TITLE>TooAwoo</TITLE>
</HEAD>
<BODY>
<APPLET archive="TooAwoo.jar" code="TooAwoo" width=1024 height=800>
Your browser does not support Java, so nothing is displayed.
</APPLET>
</BODY>
</HTML>
*/Total number of lines: 486
Weight: 15 199 bytes
Total number of files: 5
TooAwoo.java
ScrollablePicture.java
Corner.java
Rule.java
TooAwoo.html
... in that order in my code
The major default is: I cannot have that BuffuredImage at the left of the screen if run using bImp at line 91 of TooAwoo.java.
Minor bug: the JToggle button (inch/cm) does not fires-up correctly. Nothing change.
Anyway feel free to fire at me if you believe its a good strategy. I will remain very positive to all comments and suggestions.
Thanks.
dimitryous r.