asked on

Printing in Threads

I need the user to be able to manuever within a GUI while the user is printing (from Java).
Im trying to get Java2D printing to run in a separate thread.
Java 2D printing sometimes takes 2-3 minutes to run, thats alot of time for a user to be staring at the screen.
I have a print method (in the GUI class) that has this code
fragment:

try {
PrinterJob printerjob= PrinterJob.getPrinterJob();
PageFormat pf= printerjob.defaultPage();
printerjob.setPrintable(new PrintGraphPainter(linegraph.getImages()),pf);
if (printerjob.printDialog()) {
printerjob.print();
}
}
catch (PrinterException pe) {
System.out.println("Print Error");
pe.printStackTrace();
}

Heres the PrintGraphPainter class:
//PrintGraphPainter.java
import java.awt.*;
import java.awt.print.*;

class PrintGraphPainter implements Printable {

Image[] images;

public PrintGraphPainter(Image[] images) {
this.images=images;
}
public synchronized int print(Graphics g, PageFormat pf, int pageIndex) throws PrinterException {

if (pageIndex < 1) {
Dimension f= new Dimension((int)pf.getImageableWidth(),(int)pf.getImageableHeight());
int XIMG=(int) (f.width-10); int YIMG=(int)(XIMG * .5042);
int XIMG2=(int)(f.width-10); int YIMG2=(int)(XIMG2 * .1433);
int XIMG3=(int)(f.width-10); int YIMG3=(int)(XIMG3 * .07163);
g.drawImage(images[0],(int)pf.getImageableX(),(int)pf.getImageableY(),XIMG3,YIMG3,null);
g.drawImage(images[1],(int)pf.getImageableX(),(int)pf.getImageableY()+YIMG3,XIMG,YIMG,null);
g.drawImage(images[2],(int)pf.getImageableX(),(int)pf.getImageableY()+YIMG3+YIMG,XIMG2,YIMG2,null);
g.drawRect((int)pf.getImageableX(),(int)pf.getImageableY(),XIMG,YIMG+YIMG2+YIMG3);
return Printable.PAGE_EXISTS;
}
else
return Printable.NO_SUCH_PAGE;
}
}

Do I make the PrintGraphPainter class implement the Runnable interface?

Im using JDK1.2 on Win95.

malexiev

I'm not familiar with Java 2D but I think you should put your "slow" part of code in a thread
like this :

Thread t = new Thread () {
public void run() {
try {
PrinterJob printerjob= PrinterJob.getPrinterJob();
PageFormat pf= printerjob.defaultPage();
printerjob.setPrintable(new PrintGraphPainter(linegraph.getImages()),pf);
if (printerjob.printDialog()) {
printerjob.print();
}
}
catch (PrinterException pe) {
System.out.println("Print Error");
pe.printStackTrace();
}
}
};

t.start();

mbunkows

ASKER

Good thing I asked I thought this was actually going to take some work!
Post an answer and I'll give you an A
Thanks!

ASKER CERTIFIED SOLUTION

malexiev

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