/*
* Copyright (c) 1997, 2005, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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*/
package java.awt.print;
import java.awt.Graphics;
/**
* The <code>Printable</code> interface is implemented
* by the <code>print</code> methods of the current
* page painter, which is called by the printing
* system to render a page. When building a
* {@link Pageable}, pairs of {@link PageFormat}
* instances and instances that implement
* this interface are used to describe each page. The
* instance implementing <code>Printable</code> is called to
* print the page's graphics.
* <p>
* A <code>Printable(..)</code> may be set on a <code>PrinterJob</code>.
* When the client subsequently initiates printing by calling
* <code>PrinterJob.print(..)</code> control
* <p>
* is handed to the printing system until all pages have been printed.
* It does this by calling <code>Printable.print(..)</code> until
* all pages in the document have been printed.
* In using the <code>Printable</code> interface the printing
* commits to image the contents of a page whenever
* requested by the printing system.
* <p>
* The parameters to <code>Printable.print(..)</code> include a
* <code>PageFormat</code> which describes the printable area of
* the page, needed for calculating the contents that will fit the
* page, and the page index, which specifies the zero-based print
* stream index of the requested page.
* <p>
* For correct printing behaviour, the following points should be
* observed:
* <ul>
* <li> The printing system may request a page index more than once.
* On each occasion equal PageFormat parameters will be supplied.
*
* <li>The printing system will call <code>Printable.print(..)</code>
* with page indexes which increase monotonically, although as noted above,
* the <code>Printable</code> should expect multiple calls for a page index
* and that page indexes may be skipped, when page ranges are specified
* by the client, or by a user through a print dialog.
*
* <li>If multiple collated copies of a document are requested, and the
* printer cannot natively support this, then the document may be imaged
* multiple times. Printing will start each copy from the lowest print
* stream page index page.
*
* <li>With the exception of re-imaging an entire document for multiple
* collated copies, the increasing page index order means that when
* page N is requested if a client needs to calculate page break position,
* it may safely discard any state related to pages < N, and make current
* that for page N. "State" usually is just the calculated position in the
* document that corresponds to the start of the page.
*
* <li>When called by the printing system the <code>Printable</code> must
* inspect and honour the supplied PageFormat parameter as well as the
* page index. The format of the page to be drawn is specified by the
* supplied PageFormat. The size, orientation and imageable area of the page
* is therefore already determined and rendering must be within this
* imageable area.
* This is key to correct printing behaviour, and it has the
* implication that the client has the responsibility of tracking
* what content belongs on the specified page.
*
* <li>When the <code>Printable</code> is obtained from a client-supplied
* <code>Pageable</code> then the client may provide different PageFormats
* for each page index. Calculations of page breaks must account for this.
* </ul>
* <p>
* @see java.awt.print.Pageable
* @see java.awt.print.PageFormat
* @see java.awt.print.PrinterJob
*/
public interface Printable {
/**
* Returned from {@link #print(Graphics, PageFormat, int)}
* to signify that the requested page was rendered.
*/
int PAGE_EXISTS = 0;
/**
* Returned from <code>print</code> to signify that the
* <code>pageIndex</code> is too large and that the requested page
* does not exist.
*/
int NO_SUCH_PAGE = 1;
/**
* Prints the page at the specified index into the specified
* {@link Graphics} context in the specified
* format. A <code>PrinterJob</code> calls the
* <code>Printable</code> interface to request that a page be
* rendered into the context specified by
* <code>graphics</code>. The format of the page to be drawn is
* specified by <code>pageFormat</code>. The zero based index
* of the requested page is specified by <code>pageIndex</code>.
* If the requested page does not exist then this method returns
* NO_SUCH_PAGE; otherwise PAGE_EXISTS is returned.
* The <code>Graphics</code> class or subclass implements the
* {@link PrinterGraphics} interface to provide additional
* information. If the <code>Printable</code> object
* aborts the print job then it throws a {@link PrinterException}.
* @param graphics the context into which the page is drawn
* @param pageFormat the size and orientation of the page being drawn
* @param pageIndex the zero based index of the page to be drawn
* @return PAGE_EXISTS if the page is rendered successfully
* or NO_SUCH_PAGE if <code>pageIndex</code> specifies a
* non-existent page.
* @exception java.awt.print.PrinterException
* thrown when the print job is terminated.
*/
int print(Graphics graphics, PageFormat pageFormat, int pageIndex)
throws PrinterException;
}