printer.java

源码为Eclipse开源开发平台桌面开发工具SWT的源代码,

 * 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) {
	checkDevice();
	DOCINFO di = new DOCINFO();
	di.cbSize = DOCINFO.sizeof;
	int hHeap = OS.GetProcessHeap();
	int lpszDocName = 0;
	if (jobName != null && jobName.length() != 0) {
		/* Use the character encoding for the default locale */
		TCHAR buffer = new TCHAR(0, jobName, true);
		int byteCount = buffer.length() * TCHAR.sizeof;
		lpszDocName = OS.HeapAlloc(hHeap, OS.HEAP_ZERO_MEMORY, byteCount);
		OS.MoveMemory(lpszDocName, buffer, byteCount);
		di.lpszDocName = lpszDocName;
	}
	int lpszOutput = 0;
	if (data.printToFile && data.fileName != null) {
		/* Use the character encoding for the default locale */
		TCHAR buffer = new TCHAR(0, data.fileName, true);
		int byteCount = buffer.length() * TCHAR.sizeof;
		lpszOutput = OS.HeapAlloc(hHeap, OS.HEAP_ZERO_MEMORY, byteCount);
		OS.MoveMemory(lpszOutput, buffer, byteCount);
		di.lpszOutput = lpszOutput;
	}
	int rc = OS.StartDoc(handle, di);
	if (lpszDocName != 0) OS.HeapFree(hHeap, 0, lpszDocName);
	if (lpszOutput != 0) OS.HeapFree(hHeap, 0, lpszOutput);
	return rc > 0;
}

/**
 * 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() {
	checkDevice();
	OS.EndDoc(handle);
}

/**
 * Cancels a print job in progress. 
 *
 * @exception SWTException <ul>
 *    <li>ERROR_DEVICE_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 */
public void cancelJob() {
	checkDevice();
	OS.AbortDoc(handle);
}

/**
 * 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() {
	checkDevice();
	int rc = OS.StartPage(handle);
	if (rc <= 0) OS.AbortDoc(handle);
	return rc > 0;
}

/**
 * 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() {
	checkDevice();
	OS.EndPage(handle);
}

/**
 * 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() {
	checkDevice();
	int dpiX = OS.GetDeviceCaps(handle, OS.LOGPIXELSX);
	int dpiY = OS.GetDeviceCaps(handle, OS.LOGPIXELSY);
	return new Point(dpiX, dpiY);
}

/**
 * Returns a rectangle describing the receiver's size and location.
 * For a printer, this is the size of a page, in pixels.
 *
 * @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() {
	checkDevice();
	int width = OS.GetDeviceCaps(handle, OS.PHYSICALWIDTH);
	int height = OS.GetDeviceCaps(handle, OS.PHYSICALHEIGHT);
	return new Rectangle(0, 0, width, height);
}

/**
 * Returns a rectangle which describes the area of the
 * receiver which is capable of displaying data.
 * For a printer, this is the size of the printable area
 * of a page, in pixels.
 * 
 * @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() {
	checkDevice();
	int width = OS.GetDeviceCaps(handle, OS.HORZRES);
	int height = OS.GetDeviceCaps(handle, OS.VERTRES);
	return new Rectangle(0, 0, width, height);
}

/**
 * Given a desired <em>client area</em> for the receiver
 * (as described by the arguments), returns the bounding
 * rectangle which would be required to produce that client
 * area.
 * <p>
 * In other words, it returns a rectangle such that, if the
 * receiver's bounds were set to that rectangle, the area
 * of the receiver which is capable of displaying data
 * (that is, not covered by the "trimmings") would be the
 * rectangle described by the arguments (relative to the
 * receiver's parent).
 * </p>
 * Note that there is no setBounds for a printer. This method
 * is usually used by passing in the client area (the 'printable
 * area') of the printer. It can also be useful to pass in 0, 0, 0, 0.
 * 
 * @param x the desired x coordinate of the client area
 * @param y the desired y coordinate of the client area
 * @param width the desired width of the client area
 * @param height the desired height of the client area
 * @return the required bounds to produce the given client area
 *
 * @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) {
	checkDevice();
	int printX = -OS.GetDeviceCaps(handle, OS.PHYSICALOFFSETX);
	int printY = -OS.GetDeviceCaps(handle, OS.PHYSICALOFFSETY);
	int printWidth = OS.GetDeviceCaps(handle, OS.HORZRES);
	int printHeight = OS.GetDeviceCaps(handle, OS.VERTRES);
	int paperWidth = OS.GetDeviceCaps(handle, OS.PHYSICALWIDTH);
	int paperHeight = OS.GetDeviceCaps(handle, OS.PHYSICALHEIGHT);
	int hTrim = paperWidth - printWidth;
	int vTrim = paperHeight - printHeight;
	return new Rectangle(x + printX, y + printY, width + hTrim, height + vTrim);
}

/**
 * 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;
}

/**
 * Checks the validity of this device.
 *
 * @exception SWTException <ul>
 *    <li>ERROR_DEVICE_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 */
protected void checkDevice() {
	if (handle == 0) SWT.error(SWT.ERROR_DEVICE_DISPOSED);
}

/**	 
 * Releases any internal state prior to destroying this printer.
 * This method is called internally by the dispose
 * mechanism of the <code>Device</code> class.
 */
protected void release() {
	super.release();
	data = null;
}

/**	 
 * Destroys the printer handle.
 * This method is called internally by the dispose
 * mechanism of the <code>Device</code> class.
 */
protected void destroy() {
	if (handle != 0) OS.DeleteDC(handle);
	handle = 0;
}

}