Java Reference
In-Depth Information
Example 12−3: HardcopyWriter.java (continued)
hw.setFontStyle(Font.BOLD);
out.println("Dimensions:");
hw.setFontStyle(Font.PLAIN);
out.println("\tResolution: " + hw.pagedpi + " dots per inch");
out.println("\tPage width (pixels): " + hw.pagesize.width);
out.println("\tPage height (pixels): " + hw.pagesize.height);
out.println("\tWidth inside margins (pixels): " + hw.width);
out.println("\tHeight inside margins (pixels): " + hw.height);
out.println("\tCharacters per line: " + cols);
out.println("\tLines per page: " + rows);
// Skip down to the bottom of the page
for(int i = 0; i < rows-30; i++) out.println();
// And mark the lower left and lower right
out.print("+"); // lower-left
for(int i=0;i<cols-2;i++) out.print(" "); // space-over
out.print("+");
// lower-right
// Close the output stream, forcing the page to be printed
out.close();
}
}
}
Printing Swing Documents
Example 10-21 in Chapter 10 demonstrated the power of
javax.swing.
text.JTextComponent
to display complex documents, including HTML documents.
One feature missing from
JTextComponent
, however, is the ability to print those
documents. Example 10-21 included a printing feature based on a
PrintableDocu-
ment
class, which is listed in Example 12-4.
PrintableDocument
uses the Java 1.2 Printing API. In addition to implementing the
Printable
interface, this example also implements the
Pageable
interface.
Page-
able
represents a multipage document and defines three methods:
getNumberOf-
Pages()
, which returns the number of pages in the document;
getPageFormat()
,
which returns the size and orientation of each page of the document; and
get-
Printable()
, which returns a
Printable
object that represents each page.
Beyond demonstrating the use of the
Pageable
and
Printable
interfaces, the
example also shows the inner workings of the
javax.swing.text
package. In this
package,
Document
objects are composed of nested
Element
objects, which are dis-
played on the screen (or a printer) by a parallel hierarchy of
View
objects.
javax.swing.text
is one of the more obscure areas of Swing, so don't worry if
you don't understand all the details.
Unfortunately, the
PrintableDocument
class is not as robust and reliable as I
would like. In my tests, I have found that it occasionally breaks a page in the mid-
dle of a line of text, placing half the line at the bottom of one page and the rest at
the top of the next page. I am uncertain whether the bug lies in
PrintableDocu-
ment
or the
javax.swing.text
package. Also,
PrintableDocument
doesn't handle
unbreakable wide lines very well. When a document contains an unbreakable line
