/*

 * Copyright (c) 1997, 2013, 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;

}