Printing classes

CPrinterDevice and MPageRegionPrinter are two classes fundamental to every print operation. CPrinterDevice encapsulates a printing device. Its uses include:

• converting to and from the co-ordinates of the printed page (in twips) and the co-ordinates of the target device (in pixels). When in print preview mode, for example, the target device is the screen.

• selecting a printer device and retrieving its model name and UID

A device has a page specification, giving the page orientation and the size, encapsulated in the TPageSpec class.

Pages are printed in regions of a page, called bands. An application implements the band printing interface, MPageRegionPrinter, to draw the requested region to the printer device. The attributes of the printed band are encapsulated in TBandAttributes.

Additional, but less important classes, are:

• CPrinterPort, and its sub-classes: used to set whether print output should be sent to a serial or parallel port, or via infrared or to a file or fax.

• CPrinterControl: used to set the graphics context for the print operation, and controlling its progress and termination.