Java tutorial
/******************************************************************************* * Copyright (c) 2000, 2011 IBM Corporation and others. * All rights reserved. This program and the accompanying materials * are made available under the terms of the Eclipse Public License v1.0 * which accompanies this distribution, and is available at * http://www.eclipse.org/legal/epl-v10.html * * Contributors: * IBM Corporation - initial API and implementation *******************************************************************************/ package org.eclipse.swt.printing; import org.eclipse.swt.*; import org.eclipse.swt.graphics.*; /** * Instances of this class are used to print to a printer. * Applications create a GC on a printer using <code>new GC(printer)</code> * and then draw on the printer GC using the usual graphics calls. * <p> * A <code>Printer</code> object may be constructed by providing * a <code>PrinterData</code> object which identifies the printer. * A <code>PrintDialog</code> presents a print dialog to the user * and returns an initialized instance of <code>PrinterData</code>. * Alternatively, calling <code>new Printer()</code> will construct a * printer object for the user's default printer. * </p><p> * Application code must explicitly invoke the <code>Printer.dispose()</code> * method to release the operating system resources managed by each instance * when those instances are no longer required. * </p> * * @see PrinterData * @see PrintDialog * @see <a href="http://www.eclipse.org/swt/snippets/#printing">Printing snippets</a> * @see <a href="http://www.eclipse.org/swt/">Sample code and further information</a> */ public final class Printer extends Device { PrinterData data; /** * Returns an array of <code>PrinterData</code> objects * representing all available printers. If there are no * printers, the array will be empty. * * @return an array of PrinterData objects representing the available printers */ public static PrinterData[] getPrinterList() { PrinterData printerList[] = new PrinterData[0]; return printerList; } /** * Returns a <code>PrinterData</code> object representing * the default printer or <code>null</code> if there is no * default printer. * * @return the default printer data or null * * @since 2.1 */ public static PrinterData getDefaultPrinterData() { return null; } /** * Constructs a new printer representing the default printer. * <p> * Note: You must dispose the printer when it is no longer required. * </p> * * @exception SWTError <ul> * <li>ERROR_NO_HANDLES - if there is no valid default printer * </ul> * * @see Device#dispose */ public Printer() { this(getDefaultPrinterData()); } /** * Constructs a new printer given a <code>PrinterData</code> * object representing the desired printer. If the argument * is null, then the default printer will be used. * <p> * Note: You must dispose the printer when it is no longer required. * </p> * * @param data the printer data for the specified printer, or null to use the default printer * * @exception IllegalArgumentException <ul> * <li>ERROR_INVALID_ARGUMENT - if the specified printer data does not represent a valid printer * </ul> * @exception SWTError <ul> * <li>ERROR_NO_HANDLES - if there are no valid printers * </ul> * * @see Device#dispose */ public Printer(PrinterData data) { super(data); SWT.error(SWT.ERROR_NO_HANDLES); } /** * Invokes platform specific functionality to allocate a new GC handle. * <p> * <b>IMPORTANT:</b> This method is <em>not</em> part of the public * API for <code>Printer</code>. It is marked public only so that it * can be shared within the packages provided by SWT. It is not * available on all platforms, and should never be called from * application code. * </p> * * @param data the platform specific GC data * @return the platform specific GC handle * * @noreference This method is not intended to be referenced by clients. */ public int internal_new_GC(GCData data) { return 0; } /** * Invokes platform specific functionality to dispose a GC handle. * <p> * <b>IMPORTANT:</b> This method is <em>not</em> part of the public * API for <code>Printer</code>. It is marked public only so that it * can be shared within the packages provided by SWT. It is not * available on all platforms, and should never be called from * application code. * </p> * * @param hDC the platform specific GC handle * @param data the platform specific GC data * * @noreference This method is not intended to be referenced by clients. */ public void internal_dispose_GC(int xGC, GCData data) { } /** * Starts a print job and returns true if the job started successfully * and false otherwise. * <p> * This must be the first method called to initiate a print job, * followed by any number of startPage/endPage calls, followed by * endJob. Calling startPage, endPage, or endJob before startJob * will result in undefined behavior. * </p> * * @param jobName the name of the print job to start * @return true if the job started successfully and false otherwise. * * @exception SWTException <ul> * <li>ERROR_DEVICE_DISPOSED - if the receiver has been disposed</li> * </ul> * * @see #startPage * @see #endPage * @see #endJob */ public boolean startJob(String jobName) { return true; } /** * Ends the current print job. * * @exception SWTException <ul> * <li>ERROR_DEVICE_DISPOSED - if the receiver has been disposed</li> * </ul> * * @see #startJob * @see #startPage * @see #endPage */ public void endJob() { } /** * Cancels a print job in progress. * * @exception SWTException <ul> * <li>ERROR_DEVICE_DISPOSED - if the receiver has been disposed</li> * </ul> */ public void cancelJob() { } /** * Starts a page and returns true if the page started successfully * and false otherwise. * <p> * After calling startJob, this method may be called any number of times * along with a matching endPage. * </p> * * @return true if the page started successfully and false otherwise. * * @exception SWTException <ul> * <li>ERROR_DEVICE_DISPOSED - if the receiver has been disposed</li> * </ul> * * @see #endPage * @see #startJob * @see #endJob */ public boolean startPage() { return true; } /** * Ends the current page. * * @exception SWTException <ul> * <li>ERROR_DEVICE_DISPOSED - if the receiver has been disposed</li> * </ul> * * @see #startPage * @see #startJob * @see #endJob */ public void endPage() { } /** * Returns a point whose x coordinate is the horizontal * dots per inch of the printer, and whose y coordinate * is the vertical dots per inch of the printer. * * @return the horizontal and vertical DPI * * @exception SWTException <ul> * <li>ERROR_DEVICE_DISPOSED - if the receiver has been disposed</li> * </ul> */ public Point getDPI() { return new Point(0, 0); } /** * Returns a rectangle describing the receiver's size and location. * <p> * For a printer, this is the size of the physical page, in pixels. * </p> * * @return the bounding rectangle * * @exception SWTException <ul> * <li>ERROR_DEVICE_DISPOSED - if the receiver has been disposed</li> * </ul> * * @see #getClientArea * @see #computeTrim */ public Rectangle getBounds() { return null; } /** * Returns a rectangle which describes the area of the * receiver which is capable of displaying data. * <p> * For a printer, this is the size of the printable area * of the page, in pixels. * </p> * * @return the client area * * @exception SWTException <ul> * <li>ERROR_DEVICE_DISPOSED - if the receiver has been disposed</li> * </ul> * * @see #getBounds * @see #computeTrim */ public Rectangle getClientArea() { return null; } /** * Given a <em>client area</em> (as described by the arguments), * returns a rectangle, relative to the client area's coordinates, * that is the client area expanded by the printer's trim (or minimum margins). * <p> * Most printers have a minimum margin on each edge of the paper where the * printer device is unable to print. This margin is known as the "trim." * This method can be used to calculate the printer's minimum margins * by passing in a client area of 0, 0, 0, 0 and then using the resulting * x and y coordinates (which will be <= 0) to determine the minimum margins * for the top and left edges of the paper, and the resulting width and height * (offset by the resulting x and y) to determine the minimum margins for the * bottom and right edges of the paper, as follows: * <ul> * <li>The left trim width is -x pixels</li> * <li>The top trim height is -y pixels</li> * <li>The right trim width is (x + width) pixels</li> * <li>The bottom trim height is (y + height) pixels</li> * </ul> * </p> * * @param x the x coordinate of the client area * @param y the y coordinate of the client area * @param width the width of the client area * @param height the height of the client area * @return a rectangle, relative to the client area's coordinates, that is * the client area expanded by the printer's trim (or minimum margins) * * @exception SWTException <ul> * <li>ERROR_DEVICE_DISPOSED - if the receiver has been disposed</li> * </ul> * * @see #getBounds * @see #getClientArea */ public Rectangle computeTrim(int x, int y, int width, int height) { return new Rectangle(0, 0, 0, 0); } /** * Returns a <code>PrinterData</code> object representing the * target printer for this print job. * * @return a PrinterData object describing the receiver */ public PrinterData getPrinterData() { return data; } }