[news.eclipse.platform.swt] Printing content of the Composite...

[user@xxxxxxxxxxxxxx]

I try to print the content of my Composite.
I try to send to the printer Image mBuffer produced with my method, 
which called during redrawing.
But printer shows nothing. what is the plausible reason?

Sergei.

PrintDialog dialog = new PrintDialog(this.getShell(), SWT.NULL);
PrinterData printerData = dialog.open();
if (printerData == null)
    return;
Printer printer = new Printer(printerData);
Point screenDPI = this.getDisplay().getDPI();
Point printerDPI = printer.getDPI();
int scaleFactor = printerDPI.x / screenDPI.x;
Rectangle trim = printer.computeTrim(0, 0, 0, 0);

if (printer.startJob("Print FlowComposite")) {
    if (printer.startPage()) {
        GC gc = new GC(printer);

        Image mBuffer = new Image(
            FlowComposite.this.getDisplay(),
            size.x,
            size.y);
        GC gc2 = new GC(mBuffer);
        onPaint(gc2);
        gc2.dispose();

        gc.drawImage(
            mBuffer,
            0,
            0,
            mBuffer.getImageData().width,
            mBuffer.getImageData().height,
            -trim.x,
            -trim.y,
            scaleFactor * mBuffer.getImageData().width,
            scaleFactor * mBuffer.getImageData().height);
            gc.dispose();
            printer.endPage();
        }
        printer.endJob();
    }
    printer.dispose();
} catch (SWTError e) {
    e.printStackTrace();
}