Best books about JAVA programming:

• Head First JAVA, Second Editon
• Effective Java Programming Language Guide
• Professional Java, JDK 5 Edition
• Ivor Horton's Beginning Java 2, JDK 5 Edition

JAVA JTree Diabled icon

The following code disable JTree node dynamically. This example has three files: DisabledNodeTreeExample2.java,DisabledNode.java and GraydIcon.java.

/*Example modified from http://www.crionics.com/products/opensource/faq/swing_ex/JTableExamples2.html
*/



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

public class GraydIcon implements Icon {
Icon icon;
Image image;

public GraydIcon(Icon icon) {
this.icon = icon;
}

public void paintIcon(Component c, Graphics g, int x, int y) {
if (image == null) {
Image orgImage = c.createImage(getIconWidth(), getIconHeight());
Graphics imageG = orgImage.getGraphics();
Color background = c.getBackground();
imageG.setColor(background);
imageG.fillRect(0,0, getIconWidth(), getIconHeight() );

icon.paintIcon(c,imageG,x,y);

ImageFilter colorfilter = new GrayFilter();
image = c.createImage(
new FilteredImageSource(orgImage.getSource(),colorfilter));

}
g.drawImage(image, x, y, null);
}

public int getIconWidth() { return icon.getIconWidth(); }
public int getIconHeight() { return icon.getIconHeight(); }

 

class GrayFilter extends RGBImageFilter {

public GrayFilter() {
// If I set ture, black is gone?!
//canFilterIndexColorModel = true;
}

public int filterRGB(int x, int y, int rgb) {
int r = (rgb & 0xff0000) >> 16;
int g = (rgb & 0x00ff00) >> 8;
int b = (rgb & 0x0000ff);
int iy = (int)(r + g + b)/3;
iy = Math.min(255, iy);
return ((rgb & 0xff000000)
| (iy << 16)
| (iy << 8)
| iy);
}
}

}