Windows Driver Kit (WDK) Documentation Blog : Printing

XPS Document API Now Available for Printer Driver Filter Modules

wdkblog — Sat, 11 Jul 2009 00:32:00 GMT

If you are a Print Driver developer using the XPS Filter Pipeline, you can now use unmanaged XPS functions that were previously only available as .NET managed code. Because these functions were originally written for .NET, they could not be called from a Print driver until now.

These XPS functions will enable driver developers to modify XPS documents in greater detail when they are in the filter pipeline. This will make it possible to make custom changes to the documents before they get to the printer. In addition, this API allows you to have access to the document metadata and content.

This API was previously unavailable to Print Driver developers, but has been recently converted to unmanaged code and is now documented in the Windows SDK. The new documentation includes overviews of the XPS Object Model and complete coverage of all interfaces, methods, structures, and enumerators that are implemented by the XPS API.

For more information, see the XPS Document Programming Guide and Reference at http://msdn.microsoft.com/en-us/library/dd316976(VS.85).aspx.

－Seth McEvoy [MSFT], WDK Senior Programming Writer

Update to Windows 7 RC Version of the XPS Rasterization Filter Service Sample

wdkblog — Wed, 01 Jul 2009 05:00:00 GMT

Here are two updates that will help Printer driver developers who are working with the RC version of the XPS Rasterization Filter Service sample.

1. If you are using the RC version of the XPS Rasterization Filter Service sample, it is strongly recommended that you work directly with the WIC bitmap returned from the XPS Rasterization service rather than the calls into WIC to encode each band as a TIFF. The sample calls into WIC for encoding each band were for demonstration purposes only and are not recommended for larger applications because they could be inefficient and difficult.

2. In the sample, the output file consists of a series of per-band TIFFs. Because this file will be a series of complete TIFFs and not a single-page TIFF, opening the file in a viewer will only display the first band of the first page. More details can be found in the bitmaphandler.cpp file that is included in the sample source code.

The Windows 7 RTM version of the sample documentation will include this update. In the meantime, until Windows 7 is released, apply these changes to the sample documentation at http://msdn.microsoft.com/en-us/library/dd434895.aspx.

－Seth McEvoy [MSFT], WDK Senior Programming Writer

New for Windows 7 – Distributed Scan Management

wdkblog — Tue, 03 Mar 2009 04:43:00 GMT

Distributed Scan Management is a new Windows 7 feature that will make it easier and more efficient for corporations to use scanners to create and route documents in their business networks. In the past, corporate IT departments often found it difficult to include paper-based scanned documents into their electronic communications. Distributed Scan Management is an innovative new technique that makes it possible to easily use scanners to integrate paper information into corporate computer-based networks more effectively than ever before.

For example, this could be used when a corporate employee has to submit paper receipts for business expenses. With Distributed Scan Management, an employee could use a scanner to submit them electronically. They would first put the receipt into the scanner and the scan management system would be able to authenticate the employee's status and then offer them a set of choices on where to deliver the receipt information, such as an email address, a SharePoint server, or a file server.

For Windows 7, the WDK documentation will provide programming information that scanner manufacturers will need in order to develop code for this new distributed scanning system. For more information, see http://go.microsoft.com/fwlink/?LinkId=144358

-- Seth McEvoy [MSFT], WDK Senior Programmer Writer

New for Windows 7 - XPS Print Driver Rasterization Service

wdkblog — Tue, 03 Mar 2009 04:22:00 GMT

The new XPS Print Rasterization service has been created to convert XPS documents to bitmaps, simplifying printer driver development by eliminating the need to write your own XPS filter conversion routine. Previous to Windows 7, you had to write extensive code to convert XML-based XPS documents to raster-based bitmaps. By making just a few simple method calls, you can take advantage of this new rasterization service to transform fixed pages in an XPS document to bitmap images suitable for your print device.

How Does It Work?

The XPS Print Driver Rasterization service is easy to use. You need to write only a few lines of COM filter code to access this feature.

The steps for using this service in an XPSDrv COM filter are:

· Get a reference to the Rasterization factory object from the print pipeline property bag. Use the IPrintPipelinePropertyBag::GetProperty method to retrieve the MS_IXpsRasterizationFactory object reference.

· IUnknown::QueryInterface to get the IXpsRasterizationFactory interface.

· Then call the IXpsRasterizationFactory::CreateRasterizer method to create XPS rasterizer objects.

· Create a new rasterizer object for every fixed page you want to render to a bitmap.

· When the factory object is no longer needed, the filter should release the object by calling the Release method on the object's IXpsRasterizationFactory interface.

The interfaces that are provided by the Rasterization service are:

IXpsRasterizationFactory

This interface provides a way to create rasterizer objects. It has one method, IXpsRasterizationFactory::CreateRasterizer, which creates a rasterizer object. You need one object for each XPS page you want to convert to a bitmap.

IXpsRasterizer

This interface does the actual conversion. It has two methods:

· IXpsRasterizer::RasterizeRect, which converts an XPS page to a bitmap.

· IXpsRasterizer::SetMinimalLineWidth, which sets the minimum line width for the conversion.

An XPSDrv filter should also implement the following interface if it needs to cancel an in-progress XPS rasterization operation before the operation completes:

IXpsRasterizerNotificationCallback

This callback needs to implement one method, IXpsRasterizerNotificationCallback::Continue, which tells the rasterization service whether it should continue the conversion process or not.

Note: Because XPS Print Driver Rasterization service is a new development for Windows 7, it is not available on previous versions of Windows.

Want More Information?

See the following Windows Driver Kit topics:

Using the XPS Rasterization Service at http://go.microsoft.com/fwlink/?LinkId=144356
XPS Rasterization Service Reference at http://go.microsoft.com/fwlink/?LinkID=144357

-- Seth McEvoy [MSFT], WDK Senior Programmer Writer