Rotating an imageicon in JTable cells

[tan kian]

i tried putting together something from what i found on the net, but i have an error in drawImage. What should i put for the parameters Image? i cant cast my imageicon to an Image nor Graphics. please point out if there are any other parts which i did not do/did wrongly. thanks.

class Mycellrender extends DefaultTableCellRenderer
{
   ImageIcon test = new ImageIcon("test.JPG");  
   int selectcol = -1, selectrow = -1, cellwidth;     
   
   public Component getTableCellRendererComponent(JTable jt,Object value,boolean isselected, boolean hasfocus,int row,int col)
   {
      super.getTableCellRendererComponent(jt,value,isselected,hasfocus,row,col);
      
      if (col == selectcol || row == selectrow || hasfocus == true)      
         setBackground(Color.lightGray);
      else
      {    
     setBackground(null);     
         setBorder(BorderFactory.createLineBorder(Color.red));
 
     //do image rotation here
         cellwidth = jt.getColumnModel().getTotalColumnWidth();
  BufferedImage bim = new BufferedImage(cellwidth/5, cellwidth, BufferedImage.TYPE_INT_RGB);
  Graphics2D g2d = (Graphics2D)(bim.createGraphics());
  g2d.translate(cellwidth/5, 0);
  g2d.rotate(1.5708); 
  g2d.drawImage(test, 0, 0, cellwidth, cellwidth/5, jt.getColumnModel());
          
         setIcon(test); 
      }
      
      return this;
   }
   
   public void setcol(int index)   
   {
      if (selectcol == index)
         selectcol = -1;     
      else
     selectcol = index;
   }
   
   public void setrow(int index)
   {
      if (selectrow == index)
         selectrow = -1;     
      else
     selectrow = index;
   }
}

[Jeff Albertson]

Using an ImageIcon here isn't helping you that much: it seems to be used as an easy way to read from a jpeg file, but ImageIO.read is just as easy to use, and returns a BufferedImage, to boot.

That being said, have you studied ImageIcon's API to see if there are any useful methods that would enable you to successfully call drawImage?
[ May 02, 2006: Message edited by: Jeff Albertson ]

[tan kian]

ok i solved it already, thks for the reply anyway =) i have another question now though. i have some JComboBoxes, and i need to make it so that when the value in the combobox is changed, the image in the cells will need to be rotated as well according to the value in the combobox. i tried doing this but well nothing happened.

public void init()
{
final Mycellrender mcr = new Mycellrender();
JComboBox l = new JComboBox();
l.addItem("a");
l.addItem("b");
l.addItem("c");
l.addItemListener(new ItemListener()
{
public void itemStateChanged(ItemEvent e)
{
if (e.toString() == "a")
{
mcr.setL(1);
}
else if (e.toString() == "b")
{
mcr.setL(2);
}
else if (e.toString() == "c")
{
mcr.setL(3);
}
}
}

class Mycellrender extends DefaultTableCellRenderer
{
Random rand = new Random(255);
int choosel;

public Component getTableCellRendererComponent(JTable jt,Object value,boolean isselected, boolean hasfocus,int row,int col)
{
super.getTableCellRendererComponent(jt,value,isselected,hasfocus,row,col);

//if a cell is selected
if (blah blah blah)
{
setBackground(Color.GRAY);
}
else
{
if (rand.nextInt(100) < 25 || choosel == 1)
{
//do stuff like rotating an image
}
else
//do other stuff
}

return this;
}

public void setL(int index)
{
choosel = index;
}
}

[Jeff Albertson]

First, a couple suggestions:

1. When asking a new and potentially unrelated question, it's a good idea to start a new thread.
2. Use code tags for your code.

Back to your code: here's a hint. When trying to understand what's wrong with code, break it into smaller pieces. Your code have two parts: one half is listening to a combo box, and the other half is doing something in a table renderer. This two halfs are quite independent. Test each in isolation. For example, your item listener is doing a case analysis on e.toString() -- why not print this string out to see if it is what you are expecting it to be:

System.out.println(e.toString());

[Craig Wood]

There are a number of ways of doing this. The idea in this one is to make up an
ImageIcon for each angle in the JComboBox.

public class HighlightTest extends Applet
{
    String[] rotationAngles;
 
    public void init()
    {
        BufferedImage image = getImage();
        rotationAngles = new String[] { "0", "45", "90" };
        ...
        Mycellrender mcr = new Mycellrender(getIcons(image));
        ...
        setLayout(new BorderLayout());
        add(sp);
        add(getComboBox(mcr, table), "South");
    }
 
    /** make an ImageIcon for each angle item in JComboBox */
    private ImageIcon[] getIcons(BufferedImage image)
    {
        ImageIcon[] icons = new ImageIcon[rotationAngles.length];
        int w = image.getWidth();
        int h = image.getHeight();
        Dimension size = getMinimumIconSize(w, h);
        //System.out.printf("size %s", size);
        for(int j = 0; j < icons.length; j++)
        {
            BufferedImage bi = new BufferedImage(size.width, size.height,
                                                 BufferedImage.TYPE_INT_ARGB);
            Graphics2D g2 = bi.createGraphics();
            g2.setPaint(new Color(0,0,0,0));
            g2.fillRect(0,0,size.width,size.height);
            //g2.setPaint(Color.blue);
            //g2.drawRect(0,0,size.width-1,size.height-1);
            double phi = Math.toRadians(Integer.parseInt(rotationAngles[j]));
            double x = (size.width - w)/2;
            double y = (size.height - h)/2;
            AffineTransform at = AffineTransform.getTranslateInstance(x,y);
            at.rotate(phi, w/2, h/2);
            g2.drawRenderedImage(image, at);
            g2.dispose();
            icons[j] = new ImageIcon(bi);
        }
        //JPanel p = new JPanel(new FlowLayout(FlowLayout.CENTER, 5, 10));
        //for(ImageIcon icon : icons)
        //    p.add(new JLabel(icon));
        //JOptionPane.showMessageDialog(null, p);
        return icons;
    }
 
    /** smallest Dimension that will accomodate every image */
    private Dimension getMinimumIconSize(int w, int h)
    {
        Dimension d = new Dimension();
        for(int j = 0; j < rotationAngles.length; j++)
        {
            double phi = Math.toRadians(Integer.parseInt(rotationAngles[j]));
            int width  = (int)Math.ceil(w * Math.cos(phi) + h * Math.sin(phi));
            int height = (int)Math.ceil(w * Math.sin(phi) + h * Math.cos(phi));
            if(width > d.width)
                d.width = width;
            if(height > d.height)
                d.height = height;
        }
        return d;
    }
 
    private BufferedImage getImage()
    {
        String path = "yourImage.gif";
        BufferedImage bi = null;
        try
        {
            bi = ImageIO.read(new File(path));
        }
        catch(IOException ioe)
        {
            System.err.println("read error: " + ioe.getMessage());
        }
        //System.out.println(bi.getWidth() + "\t" + bi.getHeight());
        return bi;
    }
 
    private JPanel getComboBox(final Mycellrender mcr, final JTable table)
    {
        final JComboBox cb = new JComboBox(rotationAngles);
        cb.addActionListener(new ActionListener()
        {
            public void actionPerformed(ActionEvent e)
            {
                mcr.setRotationIndex(cb.getSelectedIndex());
                table.repaint();
            }
        });
        JPanel panel = new JPanel();
        panel.add(cb);
        return panel;
    }
    ...
}
 
class Mycellrender extends DefaultTableCellRenderer
{
    ImageIcon[] icons;
    int rotationIndex;
    final int imageRow = 0;
    int selectcol = -1, selectrow = -1;
 
    public Mycellrender(ImageIcon[] icons)
    {
        this.icons = icons;
        rotationIndex = 0;
    }
 
    public Component getTableCellRendererComponent(JTable jt,Object value,
                          boolean isselected, boolean hasfocus,int row,int col)
    {
        ...
        else if(isselected)
            setBackground(jt.getSelectionBackground());
        else
            setBackground(jt.getBackground());
        if(row == imageRow)
            setIcon(icons[rotationIndex]);
        else
            setIcon(null);
 
        return this;
    }
 
    ...
 
    public void setRotationIndex(int index) { rotationIndex = index; }
}

[tan kian]

thks, i will try it out and come back with any questions.