Print JTree on several pages

[Amelie Cornelis]

Hello,

I would like to print my JTree on several pages. I have implemented both Printable and Pageable, but only the first page prints correctly. The second page is just a repeat of the first one.

In my tree class:

public class EntityTree extends JTree implements Autoscroll, Printable, Pageable {
 
...
 
public int print(Graphics g, PageFormat pf, int pn) throws PrinterException {

Graphics2D g2d = (Graphics2D) g;
 
// check there still is something to draw
if(pn<0 || pn>=getNumberOfPages() ) return Printable.NO_SUCH_PAGE;
 
//// size on a page
//int height = (int)pf.getImageableHeight();
//
//// the whole tree area
//Rectangle overall = getBounds();
//// first node to draw
//TreePath first = getClosestPathForLocation(0, pn*height);
//Rectangle fb = getPathBounds(first);
//int start = fb.y;
//// the last node to draw
//TreePath last = getClosestPathForLocation(0, (pn+1)*height);
//Rectangle lb = getPathBounds(last);
//int stop = lb.y + lb.height;
//// start drawing before first and stop after last
//g2d.setClip(overall.x, start, overall.width, stop-start);
g2d.translate(pf.getImageableX(), pf.getImageableY());
paint(g2d);
return Printable.PAGE_EXISTS;
}
 
public int getNumberOfPages() {
double pageHeight = getPageFormat(0).getImageableHeight();
double componentHeight = getRowCount() * getRowHeight();
int nbPages = (int) Math.ceil( componentHeight / pageHeight );
return nbPages;
}
 
public PageFormat getPageFormat(int pageIndex) throws IndexOutOfBoundsException {
// same format for every page
return new PageFormat();
}
 
public Printable getPrintable(int pageIndex) throws IndexOutOfBoundsException {
return this;
}

In the applet that contains my tree:

public boolean print() {
// only print the tree on top
EntityTree tree = panel.getTree();
PrinterJob job = PrinterJob.getPrinterJob();
job.setPageable( tree );
try { 
job.print();
} catch (Exception ex) { 
return false; 
}
 
return true;
}

The commented lines were supposed to shift the display to the pn-th page, but it does not: the nodes displayed on page 2 are at the bottom of the page, and if you put page 1 and 2 on top of each other and look by transparence, you can see it just continues to print as if on continuous piece of paper...

Thanks for any help,
Amelie.