Java Foundation Classes in a Nutshell

Example 5−2: PageableT ext.java (continued)

// Create the font we will use, and compute spacing between lines

font = new Font(FONTFAMILY, FONTSTYLE, FONTSIZE);

linespacing = (int) (FONTSIZE * LINESPACEFACTOR);

// Figure out how many lines per page and how many pages

linesPerPage = (int)Math.floor(format.getImageableHeight()/linespacing);

numPages = (lines.size()-1)/linesPerPage + 1;

}

// These are the methods of the Pageable interface.

// Note that the getPrintable() method returns this object, which means

// that this class must also implement the Printable interface.

public int getNumberOfPages() { return numPages; }

public PageFormat getPageFormat(int pagenum) { return format; }

public Printable getPrintable(int pagenum) { return this; }

/**

* This is the print() method of the Printable interface.

*Itdoes most of the printing work.

*/

public int print(Graphics g, PageFormat format, int pagenum) {

// Tell the PrinterJob if the page number is not a legal one

if ((pagenum < 0) | (pagenum >= numPages))

return NO_SUCH_PAGE;

// First time we're called, figure out the baseline for our font.

// We couldn't do this earlier because we needed a Graphics object.

if (baseline == -1) {

FontMetrics fm = g.getFontMetrics(font);

baseline = fm.getAscent();

}

// Clear the background to white. This shouldn't be necessary but is

// required on some systems to work around an implementation bug.

g.setColor(Color.white);

g.fillRect((int)format.getImageableX(), ...