Java Reference
In-Depth Information
We will be adding an instance of the
Copies
class to our
PrintAttr
object to specify the number of
copies to be printed and this will be displayed by the print dialog. We can create an object specifying
the number of copies to be produced like this:
HashPrintRequestAttributeSet printAttr = new HashPrintRequestAttributeSet();
Copies twoCopies = new Copies(2);
if (printer.isAttributeCategorySupported(twoCopies.getCategory()))
printAttr.add(twoCopies);
if(printJob.printDialog(printAttr)) { // Display print dialog
The argument to the constructor specifies the number of copies to be produced. Our object specifies just
two copies but you can go for more if you have the paper, the time, and the inclination.
Before we add this object to the print request attribute set though, we verify that the printer does
actually support the production of multiple copies. Obviously it only makes sense to set an attribute for
a printer that has the appropriate capability - you won't be able to print in color on a monochrome
printer for instance. We can call the
isAttributeCategorySupported()
method for the
PrintService
object that we obtained from the
PrinterJob
object to do this.
The
isAttributeCategorySupported()
method requires an argument of type
Class
to identify
the attribute category that we are querying, and we obtain this by calling the
getCategory()
method
for our
Copies
object. If the attribute is supported, we add the
twoCopies
object to the set
encapsulated by
printAttr
by calling its
add()
method.
You can add the three lines of code to the
actionPerformed()
method in the
FileAction
inner
class and add an import statement for the
Copies
class to
SketchFrame.java
:
import javax.print.attribute.standard.Copies;
If you recompile and run Sketcher once more, the print dialog should come up with two copies set initially.
Of course, setting thing like margin sizes and page orientation once and for all may not be satisfactory
in many cases. It is easy to envisage situations where you may want to print some pages in a document
in portrait orientation while others, perhaps containing illustrations, are printed landscape. Let's see
how we can handle that in Java.
Multipage Document Printing
If you need to print a document that contains multiple pages in a print job, you can do it in the
implementation of the
print()
method declared in the
Printable
interface. The
PrinterJob
object will continue to call this method until the value
NO
_
SUCH
_
PAGE
is returned. However, this won't
be convenient in every case. In a more complicated application than Sketcher, as well as having
different page orientations, you may want to have different class objects printing different kinds of
pages - rendering the same data as graphical or textual output for instance. You can't do this
conveniently with just one class implementing the
Printable
interface. You also need something
more flexible than just passing a class object that does printing to the
PrinterJob
object by calling its
setPrintable()
method.
