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PrintableComponent.javaAPI DocExample2516Mon Oct 11 15:07:22 BST 1999None

PrintableComponent.java

/*
 * This example is from the book "Java Foundation Classes in a Nutshell".
 * Written by David Flanagan. Copyright (c) 1999 by O'Reilly & Associates.  
 * You may distribute this source code for non-commercial purposes only.
 * You may study, modify, and use this example for any purpose, as long as
 * this notice is retained.  Note that this example is provided "as is",
 * WITHOUT WARRANTY of any kind either expressed or implied.
 */

import java.awt.*;
import java.awt.print.*;

/**
 * This wrapper class encapsulates a Component and allows it to be printed
 * using the Java 2 printing API.
 */
public class PrintableComponent implements Printable {
  // The component to be printed.
  Component c;

  /** Create a PrintableComponent wrapper around a Component */
  public PrintableComponent(Component c) { this.c = c; }

  /**
   * This method is not part of the Printable interface.  It is a method
   * that sets up the PrinterJob and initiates the printing.
   */
  public void print() throws PrinterException {
    // Get the PrinterJob object
    PrinterJob job = PrinterJob.getPrinterJob();
    // Get the default page format, then allow the user to modify it
    PageFormat format = job.pageDialog(job.defaultPage());
    // Tell the PrinterJob what to print
    job.setPrintable(this, format);
    // Ask the user to confirm, and then begin the printing process
    if (job.printDialog()) 
      job.print();
  }

  /**
   * This is the "callback" method that the PrinterJob will invoke.
   * This method is defined by the Printable interface.
   */
  public int print(Graphics g, PageFormat format, int pagenum) {
    // The PrinterJob will keep trying to print pages until we return
    // this value to tell it that it has reached the end.
    if (pagenum > 0) 
      return Printable.NO_SUCH_PAGE;

    // We're passed a Graphics object, but it can always be cast to Graphics2D
    Graphics2D g2 = (Graphics2D) g;

    // Use the top and left margins specified in the PageFormat Note
    // that the PageFormat methods are poorly named.  They specify
    // margins, not the actual imageable area of the printer.
    g2.translate(format.getImageableX(), format.getImageableY());

    // Tell the component to draw itself to the printer by passing in 
    // the Graphics2D object.  This will not work well if the component
    // has double-buffering enabled.
    c.paint(g2);

    // Return this constant to tell the PrinterJob that we printed the page.
    return Printable.PAGE_EXISTS;
  }
}